SFPD needs to crack down on Bicyclists with No Lights (& SF-GG Bridge-LarkspurRide Report)

[SMS]

Yesterday we rode from the Presidio in San Francisco over to Larkspur,
and took the ferry back to San Francisco. By the time we finished eating
a late lunch/early dinner at Taylor's Automatic Refresher, it was 5:30
and dark, as we rode along the Embarcadero back to the Presidio.

It was fine until Aquatic Park, where the lighted streets ended. I had
lights for everyone so it was no problem for us, but with the fog and
darkness it was _really_ hard to see other bicycles, and there were _a
lot_ of them, nearly all from those bicycle rental places along
Fisherman's Wharf (identifiable by the handlebar bags).

The rest of the ride back was not too enjoyable, having to strain to see
shadows of cyclists, dressed in non-reflective clothing, coming toward
us in the darkness and light fog.

One cyclist complained "you're blinding me" due to my light, which was
just a two AA Cree LED flashlight (Fenix L2DCE) attached to my handlebar
("http://nordicgroup.us/s78/images/IMG_0332.JPG"). I angled it down a
bit after that, but geez it's only a 3W LED.

Anyway, I think that these rental places should be providing at least
"being seen" front and rear lights on their bicycles at this time of
year, and that SFPD should enforce the laws on bicycle lighting,
especially in areas with no street lighting.

BTW, if you take visitors on the classic ride across the GG bridge and
take the ferry back, I recommend going all the way to Larkspur, rather
than coming back on the Sausalito or Tiburon ferries. First, you can eat
at the Marin Brewing Company right across the road from the Larkspur
ferry terminal (use the pedestrian overpass) which is much better than
those tourist traps in Sausalito or Tiburon. Second, you get a much
longer Bay Cruise than from Sausalito or Tiburon. Third, the Sausalito
and Tiburon ferries are typically packed with all those people on the
rental bicycles (as well as hordes of other tourists), but almost no one
goes all the way to Larkspur, which is really not much further than
Tiburon, and it's a nice route. There were only eight bicycles on the
boat yesterday, and less than a hundred passengers on a boat that holds
750 people.

The Sausalito-San Francisco ferry can get nasty when it gets crowded.
Last time I rode it the bar ran out of vodka for Bloody Marys and irate
tourists threw the bartender overboard. I think one of the reasons for
so many of those rental bicycles being out so late is that the number of
bicycles on the ferries is limited, and it was a really nice day
yesterday so a lot of tourists had the same idea of a ride to Sausalito
and back by ferry (which the bicycle rental companies promote). I'd
wager that a lot of bicyclists were denied boarding and decided to ride
back.

I tried to exit the Larkspur-San Francisco ferry with a Surly Long Haul
Trucker with Arkel panniers, but the owner stopped me.

The route to the Larkspur ferry terminal is now signed pretty well,
which is good since it's not an obvious route, with some disconnected
bike paths to Corte Madera and Larkspur, that you pretty much have to
use to avoid 101 unless you go a really long and hilly way around.

Taylor's Automatic is a good place to eat where you can lock your bikes
to the railing around their outdoor patio, and you can see your bikes
even from inside the restaurant. Try the pistachio milk shake.
"http://www.taylorsrefresher.com/menu/TaylorsMenuFall2008.pdf"

[ZBicyclist]

SMS wrote:
>
> Anyway, I think that these rental places should be providing at
> least
> "being seen" front and rear lights on their bicycles at this time
> of
> year, and that SFPD should enforce the laws on bicycle lighting,
> especially in areas with no street lighting.


Rental bikes that I've seen (but I'm not in the bay area) tend to
have little attached to them of value that could be removed easily.

But those Halloween blinkies they give out near trick or treat time
have to be
1. Cheap
2. Pretty be-seen visible
3. Since they are yellow, they'd be acceptable either front or rear.
Heck, real estate agents give them out free, as an advertising
gimmick.

[Tom Keats]

In article >,
"ZBicyclist" > writes:
> SMS wrote:
>>
>> Anyway, I think that these rental places should be providing at
>> least
>> "being seen" front and rear lights on their bicycles at this time
>> of
>> year, and that SFPD should enforce the laws on bicycle lighting,
>> especially in areas with no street lighting.
>
>
> Rental bikes that I've seen (but I'm not in the bay area) tend to
> have little attached to them of value that could be removed easily.
>
> But those Halloween blinkies they give out near trick or treat time
> have to be
> 1. Cheap
> 2. Pretty be-seen visible
> 3. Since they are yellow, they'd be acceptable either front or rear.
> Heck, real estate agents give them out free, as an advertising
> gimmick.

Riding in fog at night is tricky business.
So much so, I prefer not to do it. Sometimes thick
banks of fog can just swallow yellow->red (i.e:
longer wavelength) light. And passive reflectives
don't work very well in thick fog. Fog is the
one weather condition that actually fights against
your illumination system.

AFAIC foggy nights are for watching TV at home,
or making a batch of stew or clam chowder.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[SMS]

ZBicyclist wrote:

> Rental bikes that I've seen (but I'm not in the bay area) tend to
> have little attached to them of value that could be removed easily.

They do provide handlebar bags, and all the bikes have rear racks.

During times of year when it gets dark before the rental place closes
they should include an LED headlight and tail light in the bag that can
be attached without tools. The rental agreement should include a
requirement that the rider use the lights after dark.

Maybe charge something extra if the bicycle is returned after dark to
cover the cost. Maybe seal it inside a pouch and only charge if the
pouch is opened. I don't know, they can figure it out.

Their insurance company would not be too pleased if they knew that they
were renting bicycles that even if returned by the closing time are
being operated in an illegal manner that could cause the rider injury
and also expose the rental agency to liability from anyone that rider
might injure.

What would be great is if they had wheels with dynamo hubs, and dynamo
lights on all the rental bicycles, but obviously that's not going to happen.

[Tom Kunich]

"SMS" > wrote in message
...
>
> The rest of the ride back was not too enjoyable, having to strain to see
> shadows of cyclists, dressed in non-reflective clothing, coming toward us
> in the darkness and light fog.

So you made it back and are complaining because you had to be careful.

[Tom Kunich]

"nmp" > wrote in message
...
> Tom Kunich wrote:
>
>> "SMS" > wrote in message
>> ...
>>>
>>> The rest of the ride back was not too enjoyable, having to strain to
>>> see shadows of cyclists, dressed in non-reflective clothing, coming
>>> toward us in the darkness and light fog.
>>
>> So you made it back and are complaining because you had to be careful.
>
> Perhaps he's complaining because he saw so many people exposing
> themselves to danger, riding without lights. Proper bicycle lights are no
> luxury. In a lot of countries they are mandated by law.

On the bike path......

[Richard Mlynarik]

Tom Kunich wrote, On 2008-11-23 13:33:
> "SMS" > wrote in message
> ...
>>
>> The rest of the ride back was not too enjoyable, having to strain to
>> see shadows of cyclists, dressed in non-reflective clothing, coming
>> toward us in the darkness and light fog.
>
> So you made it back and are complaining because you had to be careful.

Sounds like a simply horrible experience. Just horrible.

Why no citizen's arrests of the miscreants?
Surely that would have been the least you could do.

You ought to have U-locked them to your Surly Long Haul Trucker,
covered their heads in Arkel panniers to prevent escape,
used your AA Cree LED flashlight to illuminate your Garmin
GPS unit to locate coordinates that you could communicate
at high priority to the San Francisco Police Department
Flash Response Units using your iPhone Mobile Communications
Center, and awaited Action by the Authorities.

We do regret that you did not fully enjoy your visit to
San Francisco and trust that our Customer Care Response
Team will have fully effectuated feedback-driven improvements
to our customer-facing experience by the time you make your
next visit. As a token of our regret, please accept this
Bloody Mary coupon, good on your next ferry ride to San
Francisco.

[[email protected]]

SMS who? wrote:

> Yesterday we rode from the Presidio in San Francisco over to
> Larkspur, and took the ferry back to San Francisco. By the time we
> finished eating a late lunch/early dinner at Taylor's Automatic
> Refresher, it was 5:30 and dark, as we rode along the Embarcadero
> back to the Presidio.

> It was fine until Aquatic Park, where the lighted streets ended. I
> had lights for everyone so it was no problem for us, but with the
> fog and darkness it was _really_ hard to see other bicycles, and
> there were _a lot_ of them, nearly all from those bicycle rental
> places along Fisherman's Wharf (identifiable by the handlebar bags).

> The rest of the ride back was not too enjoyable, having to strain to
> see shadows of cyclists, dressed in non-reflective clothing, coming
> toward us in the darkness and light fog.

> One cyclist complained "you're blinding me" due to my light, which
> was just a two AA Cree LED flashlight (Fenix L2DCE) attached to my
> handlebar ("http://nordicgroup.us/s78/images/IMG_0332.JPG"). I
> angled it down a bit after that, but geez it's only a 3W LED.

My laser pointer is less than 1W but is greatly blinding. Why aim a
light at the face of oncoming people unless it is a gesture of self
righteous pride. I met a guy on the Dumbarton bridge yesterday with
two of those lights aimed right in my face. He used your excuse about
how few watts they emitted.

> Anyway, I think that these rental places should be providing at
> least "being seen" front and rear lights on their bicycles at this
> time of year, and that SFPD should enforce the laws on bicycle
> lighting, especially in areas with no street lighting.

Did you consider a citizens arrest of unlit pedestrians you met? Hell
They are even worse because they have no metal reflecting bicycle.

Jobst Brandt

[Tom Keats]

In article >,
writes:
> SMS who? wrote:
>
>> Yesterday we rode from the Presidio in San Francisco over to
>> Larkspur, and took the ferry back to San Francisco. By the time we
>> finished eating a late lunch/early dinner at Taylor's Automatic
>> Refresher, it was 5:30 and dark, as we rode along the Embarcadero
>> back to the Presidio.
>
>> It was fine until Aquatic Park, where the lighted streets ended. I
>> had lights for everyone so it was no problem for us, but with the
>> fog and darkness it was _really_ hard to see other bicycles, and
>> there were _a lot_ of them, nearly all from those bicycle rental
>> places along Fisherman's Wharf (identifiable by the handlebar bags).
>
>> The rest of the ride back was not too enjoyable, having to strain to
>> see shadows of cyclists, dressed in non-reflective clothing, coming
>> toward us in the darkness and light fog.
>
>> One cyclist complained "you're blinding me" due to my light, which
>> was just a two AA Cree LED flashlight (Fenix L2DCE) attached to my
>> handlebar ("http://nordicgroup.us/s78/images/IMG_0332.JPG"). I
>> angled it down a bit after that, but geez it's only a 3W LED.
>
> My laser pointer is less than 1W but is greatly blinding. Why aim a
> light at the face of oncoming people unless it is a gesture of self
> righteous pride. I met a guy on the Dumbarton bridge yesterday with
> two of those lights aimed right in my face. He used your excuse about
> how few watts they emitted.
>
>> Anyway, I think that these rental places should be providing at
>> least "being seen" front and rear lights on their bicycles at this
>> time of year, and that SFPD should enforce the laws on bicycle
>> lighting, especially in areas with no street lighting.
>
> Did you consider a citizens arrest of unlit pedestrians you met? Hell
> They are even worse because they have no metal reflecting bicycle.

Pedestrians are only going at an average rate of 2.5 MPH.

Encountering unlit riders on a foggy, rainy, or even
a clear night can be quite unnerving. Their patterns
of movement can be sketchy, unpredictable and Brownianly
random.

Some riders are able to pull-off stealth riding (and
I honestly declare I'm not one of them.)
There's a whole bunch of others who /think/ they are.

I don't want to see any more Law Enforcement pogroms
against cyclists. We've had enough of that here in
Vancouver already.

For some reason, fellow cyclists are our own worst
enemies, with some wanting to sic The Law on those
who don't toe the line, or don't conform to certain
notions of "appropriate" behaviour.

I wish we cyclists would stop tearing ourselves apart,
and instead apply that energy toward supporting each
other in a positive, inclusive and welcoming manner.

Wouldn't that be nice?


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[C.H. Luu]

This is one of the nicest ride you can do in the north bay. I usually
head into the Marin headlans beforing going through Sausalito and then
onto Larkspur. The stretch of road between Tiburon and Larkspur is
especially scenic and has little traffic. Granted it's our right to
travel the roads, but it is rather dangerous at night. Most usually
do not travel with reflective apparel or lights (I'm guilty of this &
do not ride at night anymore). In high traffic areas, like those
around the Ferry and the Pier area in San Fancisco, this can make
riding very dangerous.

I honestly don't think that this will get any better. Be safe and
travel during daylight hours. If you must brave the darkness, be
prepared to put your foot down at a moment's notice. I've ridden
betweent the Pier area and the Presidio. Even in daylight, it's
hazardous. I would be hesitant to use clipless pedals in that area.

Please travel and come home in safety.

Claude

[SMS]

wrote:

> My laser pointer is less than 1W but is greatly blinding. Why aim a
> light at the face of oncoming people unless it is a gesture of self
> righteous pride. I met a guy on the Dumbarton bridge yesterday with
> two of those lights aimed right in my face. He used your excuse about
> how few watts they emitted.

Well it really was not aimed at anyone's face. It was already angled
down slightly, but I angled it down more after she complained. It may
have been blinding her because she had been riding in the pitch black
until I came along.

> Did you consider a citizens arrest of unlit pedestrians you met? Hell
> They are even worse because they have no metal reflecting bicycle.

It is not against the law to be an unlit pedestrian, though it should be
when you're walking on the road or on mixed use paths.

[SMS]

C.H. Luu wrote:
> This is one of the nicest ride you can do in the north bay. I usually
> head into the Marin headlans beforing going through Sausalito and then
> onto Larkspur. The stretch of road between Tiburon and Larkspur is
> especially scenic and has little traffic. Granted it's our right to
> travel the roads, but it is rather dangerous at night. Most usually
> do not travel with reflective apparel or lights (I'm guilty of this &
> do not ride at night anymore). In high traffic areas, like those
> around the Ferry and the Pier area in San Fancisco, this can make
> riding very dangerous.

The ferry and pier area is at least very well lit. There's a bike lane
on the Embarcadero for quite a way so you don't have to ride either in
traffic or on the sidewalk, though many people do. When we got down to
the Pier 39 area we rode in the streetcar lane.

The real problem area starts at Aquatic park where there is no street
lighting. Combined with the fog, it's really hard to see bicycles or
pedestrians without lights.

> I honestly don't think that this will get any better. Be safe and
> travel during daylight hours. If you must brave the darkness, be
> prepared to put your foot down at a moment's notice. I've ridden
> betweent the Pier area and the Presidio. Even in daylight, it's
> hazardous. I would be hesitant to use clipless pedals in that area.
>
> Please travel and come home in safety.

We didn't plan to be out at night, but with it getting dark so early it
can happen. OTOH, since I had lights for everyone with me, maybe we did
plan for it!

I also noticed what a huge difference our Flash Flags made in terms of
getting vehicles to not come too close. Whether it's because they don't
want to get their vehicles scratched, or because we're more visible, I
don't know, but they make a big arc around us.
"http://www.flashback.ca/bicycle.html".

[[email protected]]

C.H. Luu wrote:

> This is one of the nicest ride you can do in the north bay. I
> usually head into the Marin headlands before going through Sausalito
> and then onto Larkspur. The stretch of road between Tiburon and
> Larkspur is especially scenic and has little traffic. Granted it's
> our right to travel the roads, but it is rather dangerous at night.
> Most usually do not travel with reflective apparel or lights (I'm
> guilty of this & do not ride at night anymore). In high traffic
> areas, like those around the Ferry and the Pier area in San
> Francisco, this can make riding very dangerous.

> I honestly don't think that this will get any better. Be safe and
> travel during daylight hours. If you must brave the darkness, be
> prepared to put your foot down at a moment's notice. I've ridden
> between the Pier area and the Presidio. Even in daylight, it's
> hazardous. I would be hesitant to use clipless pedals in that area.

> Please travel and come home in safety.

This reminds me of a ride in the late 1960's when we parked on the SF
side of the GG Bridge rode to Mill Valley at dusk and climbed
Mt. Tamalpais that night under a full moon, a moon that inspired this
adventure. I recall that Kieth Vierra got a snake bite flat (the RR
ROW is rocky and rough) and because we were young and fast, it was
plenty warm. He said he wanted to find a shady spot to change his
flat under the delusion that the stark white moonlight was sunlight
and causing our sweat.

After marveling at the beautiful vista from the top of the mountain,
we descended via Panoramic Highway to HWY 1 and on down to Sausalito:

http://www.rntl.net/sausalitocam.htm

and on to the GG Bridge to the cars.

The hazard was not in meeting oncoming traffic, even though no one
had a light, but rather that in the darkness under curves in the
trees, wildlife was crossing the road. On more than one occasion we
heard, but did not see, deer running in our midst.

Discussing this later we decided, it had to be the first and last
Mt. Tamalpais full moon ride, with or without lights. In those days,
there were no cars at that time of day and no wreck.bike guys to be
incensed about "stealth" bicyclists. We were the only bikies in the
SF Bay Area that went anywhere and we knew them all by name, some of
which are pictured on Ray Hosler's site:

http://www.geocities.com/rayhosler/coastrangeslides/coast_range_slide.htm

Jobst Brandt

[SMS]

wrote:

> Discussing this later we decided, it had to be the first and last
> Mt. Tamalpais full moon ride, with or without lights. In those days,
> there were no cars at that time of day and no wreck.bike guys to be
> incensed about "stealth" bicyclists.

I would have been incensed, but I was only 8 or 9 years old.

In the 1980's I used to lead full moon all-night bike rides for some
local bike clubs, including around SF, through the tunnels, down
Lombard, and across the GG bridge. These were very fun rides with little
traffic. I never felt unsafe on these rides, and OMG some people didn't
even wear helmets! We did all have lights though. I think we scared some
of the few people that were on the streets at those times.

I remember one time I co-listed the ride with the Sierra Club cycling
section from Oakland, and two days before the ride someone from that
group got it into their head that riding at night was just exceptionally
dangerous and that when people showed up I would have to tell them that
the ride was canceled. I told them that they S.O.L.. It was amusing to
see these idiots panic and complain about me to the Sierra Club's
National office, who told them to find something more important to
complain about.

[Frank Krygowski[_2_]]

On Nov 24, 12:06*am, SMS > wrote:
> wrote:
> > My laser pointer is less than 1W but is greatly blinding. *Why aim a
> > light at the face of oncoming people unless it is a gesture of self
> > righteous pride. *I met a guy on the Dumbarton bridge yesterday with
> > two of those lights aimed right in my face. *He used your excuse about
> > how few watts they emitted.
>
> Well it really was not aimed at anyone's face. It was already angled
> down slightly, but I angled it down more after she complained. It may
> have been blinding her because she had been riding in the pitch black
> until I came along.

It was blinding her because it's a flashlight, not a proper
headlight.

Every proper headlight on every automobile, motorcycle, scooter, or
other road vehicle features optics designed to light the road but not
blind oncoming road users.

The units you've always espoused have never had proper, non-blinding
optics. Don't pretend you weren't told that 100 times.

- Frank Krygowski

[[email protected]]

Frank Krygowski wrote:

>>> My laser pointer is less than 1W but is greatly blinding. Â*Why aim
>>> a light at the face of oncoming people unless it is a gesture of
>>> self righteous pride. Â*I met a guy on the Dumbarton bridge
>>> yesterday with two of those lights aimed right in my face. Â*He
>>> used your excuse about how few watts they emitted.

>> Well it really was not aimed at anyone's face. It was already
>> angled down slightly, but I angled it down more after she
>> complained. It may have been blinding her because she had been
>> riding in the pitch black until I came along.

> It was blinding her because it's a flashlight, not a proper
> headlight.

> Every proper headlight on every automobile, motorcycle, scooter, or
> other road vehicle features optics designed to light the road but
> not blind oncoming road users.

That may be theoretically so but HID headlights on cars are blinding
just the same and seem to operate on the assumption that roads are
level and smooth, because with slightest irregularities the lights
strike oncoming drivers right in the face, just like the bicycle
lights.

> The units you've always espoused have never had proper, non-blinding
> optics. Don't pretend you weren't told that 100 times.

I sense that people with these lights are so proud of them because
they have them on in daylight, aimed into oncoming traffic at eye
level. Even in daylight the effect is annoying. My first reaction is
to wish I had my laser pointer at hand.

Here is what they advertise with blinding brightness. Watch that
light:

http://www.xenonpros.com/?gclid=CMuAj7OcjpcCFQ89awod2C1DGA

Jobst Brandt

[SMS]

wrote:

> That may be theoretically so but HID headlights on cars are blinding
> just the same and seem to operate on the assumption that roads are
> level and smooth, because with slightest irregularities the lights
> strike oncoming drivers right in the face, just like the bicycle
> lights.

The lights I find most annoying are those flashing LED bicycle lights
and HID bicycle headlights. OTOH, the former does make the cyclist
visible to motor vehicles in the daytime which is their goal, and the
latter does light the road sufficiently for high speed night riding.

I have a dynamo light on the bike I was riding in San Francisco on
Saturday night, and it was just a complete waste of perfectly good human
power to use it. Too weak to make it a good "being seen" light at the
speeds that were practical on those roads, and totally worthless as a
light to illuminate the road. As my wife said, at least people can hear
you approaching (it's a tire driven dynamo). Dynamo lights are
sufficient for low speed rides around town on familiar well-lit streets,
but on a pitch black and foggy road with hundreds of unlit bicyclists
that don't know where they're going you need something better.

[SMS]

wrote:

> Here is what they advertise with blinding brightness. Watch that
> light:
>
> http://www.xenonpros.com/?gclid=CMuAj7OcjpcCFQ89awod2C1DGA

$200 for a bicycle light, ouch.

If you want to carry something light that's sufficiently powerful for
when you get caught out at night, look at:

"http://eliteled.com/products/flashlights/fenix-l2d-q5.html"
and
"http://eliteled.com/products/accessory/fenix-bfm.html"

It's got a beam pattern that's very good for cycling, both in terms of
seeing and being seen, and it's got three brightness levels so you can
avoid blinding people if you're in an area with a lot of oncoming
bicycles on a narrow path.

When the woman said "you're blinding me" we were on a narrow path in
front of the Maritime museum at Aquatic park, and she was only about 18"
to the left. This is not a typical situation with oncoming traffic. If
both of us had had no lights then it would have been really bad!

[[email protected]]

SMS who? wrote:

>> That may be theoretically so but HID headlights on cars are
>> blinding just the same and seem to operate on the assumption that
>> roads are level and smooth, because with slightest irregularities
>> the lights strike oncoming drivers right in the face, just like the
>> bicycle lights.

> The lights I find most annoying are those flashing LED bicycle
> lights and HID bicycle headlights. OTOH, the former does make the
> cyclist visible to motor vehicles in the daytime which is their
> goal, and the latter does light the road sufficiently for high speed
> night riding.

> I have a dynamo light on the bike I was riding in San Francisco on
> Saturday night, and it was just a complete waste of perfectly good
> human power to use it. Too weak to make it a good "being seen"
> light at the speeds that were practical on those roads, and totally
> worthless as a light to illuminate the road. As my wife said, at
> least people can hear you approaching (it's a tire driven dynamo).
> Dynamo lights are sufficient for low speed rides around town on
> familiar well-lit streets, but on a pitch black and foggy road with
> hundreds of unlit bicyclists that don't know where they're going you
> need something better.

As another thread states, Bicycling is too dangerous to be done by
reasonable people. At least that is what I gather from "Take the
lane" writers, helmet wars, and need for dark goggles and intense
front and rear lights. Besides, riding on anything other than carbon
fiber is also a hazard.

Bicycling has been infested by a conformity similar to that of autos
(aka trucks and SUV's).

Jobst Brandt

[SMS]

wrote:

> Bicycling has been infested by a conformity similar to that of autos
> (aka trucks and SUV's).

There are still ample opportunities to not conform. Alas, the price of
non-conformity is often a lot higher now than in the past.

I owned an SUV before the term SUV was even coined (an old Toyota Land
Cruiser). I had to sell it once everyone had an SUV, or I would be
accused of being a conformist.

[Tom Kunich]

> wrote in message
...
>
> Besides, riding on anything other than carbon fiber is also a hazard.

In another three months I should be fully recovered from riding on carbon
fiber. My accident was last June.

[Tom Kunich]

"SMS" > wrote in message
...
>
> There are still ample opportunities to not conform. Alas, the price of
> non-conformity is often a lot higher now than in the past.

You mean that steel bikes are more expensive now?

> I owned an SUV before the term SUV was even coined (an old Toyota Land
> Cruiser). I had to sell it once everyone had an SUV, or I would be accused
> of being a conformist.

Why would anyone own a vehicle designed to look macho? That alone means that
you ain't.

[Helmut Springer]

In rec.bicycles.misc SMS > wrote:
> The lights I find most annoying are those flashing LED bicycle
> lights and HID bicycle headlights. OTOH, the former does make the
> cyclist visible to motor vehicles in the daytime which is their
> goal,

A flashing LED in bright daylight? Good one 8)


> I have a dynamo light on the bike I was riding in San Francisco on
> Saturday night, and it was just a complete waste of perfectly good
> human power to use it.

You could install a reasonable one if it wasn't against your deepest
believe 8)

--
MfG/Best regards
helmut springer panta rhei

[SMS]

Helmut Springer wrote:
> In rec.bicycles.misc SMS > wrote:
>> The lights I find most annoying are those flashing LED bicycle
>> lights and HID bicycle headlights. OTOH, the former does make the
>> cyclist visible to motor vehicles in the daytime which is their
>> goal,
>
> A flashing LED in bright daylight? Good one 8)

Obviously you've never seen one of the Cree 3W LED flashing lights. They
are extremely bright and visible in the daytime.

> You could install a reasonable one if it wasn't against your deepest
> believe 8)

I've seen people with the so-called "decent" ones. They are not much
better than the Union/Marwi. There is one supposedly really good one
from SolidLights (it's gotten good reviews from dynamo light users) but
it's like $300 just for the lamp.

[Tom Kunich]

"Helmut Springer" > wrote in message
...
> In rec.bicycles.misc SMS > wrote:
>> I have a dynamo light on the bike I was riding in San Francisco on
>> Saturday night, and it was just a complete waste of perfectly good
>> human power to use it.
>
> You could install a reasonable one if it wasn't against your deepest
> believe 8)

I have never seen a European type under-the-bottom-bracket generator being
sold here Helmut.

The kind available here are the side-of-the-tire kind that are very
inefficient and scrub a lot.

And of course the in-hub generators are the best of all. But none that I've
seen generate sufficient power for a decent headlight that is effective at
anything other than a dim glow that is supposed to alert drivers not to run
you over.

I wonder if you could couple the hub generator with an LED headlight and get
a decent illumination for riding at, say, 25 kph on an unlit roadway.

[Helmut Springer]

Tom Kunich <cyclintom@yahoo. com> wrote:
> I have never seen a European type under-the-bottom-bracket
> generator being sold here Helmut.

Those have decreased quite a lot here by now...in-hub generators
have pretty much taken over that market segment.


> I wonder if you could couple the hub generator with an LED
> headlight and get a decent illumination for riding at, say, 25 kph
> on an unlit roadway.

IMO yes: at that speed you can easily power 2 or 3 headlights with
3W LED if you wanted. With recent models like Schmidt's Edelux or
B&M's Cyo Sport it has become easier, and technology robably won't
stop there.

http://nabendynamo.de/produkte/ar_tabelle.html shows some pictures
of modern LED headlights on the German market, powered by a hub
generator ot 20km/h.

--
MfG/Best regards
helmut springer panta rhei

[SMS]

Helmut Springer wrote:
> Tom Kunich <cyclintom@yahoo. com> wrote:
>> I have never seen a European type under-the-bottom-bracket
>> generator being sold here Helmut.
>
> Those have decreased quite a lot here by now...in-hub generators
> have pretty much taken over that market segment.

Can you even buy the bottom bracket dynamos anymore? I have an old Sanyo
that still works, but I haven't seen that type for sale anywhere in the
world for a long time.

> IMO yes: at that speed you can easily power 2 or 3 headlights with
> 3W LED if you wanted. With recent models like Schmidt's Edelux or
> B&M's Cyo Sport it has become easier, and technology robably won't
> stop there.

I doubt if you could three 3W LED headlights with a 3W dynamo. Two might
be do-able at high speeds. These LED headlights waste a lot of power as
heat, as well as wasting some in the drive circuitry and regulation
circuitry.

"Efficiency and LED lifetime mainly depend on its cooling. This is why
we placed the LED on a massive copper heat sink, which in turn conducts
the heat to the aluminum housing, and then to the outside air. At high
speed the good cooling allows for an increase of 20% luminous flux
compared to usual LED headligts, some of which can reach more than 100°
Celsius (210° F)."

Of course the other issue with the Edelux is that not many people are
going to spending $212 on just a headlight.

[Helmut Springer]

SMS > wrote:
> Can you even buy the bottom bracket dynamos anymore?

Yes.


> I doubt if you could three 3W LED headlights with a 3W dynamo.

Several people in d.r.f do, as the hub generator isn't limited to 3W
at sufficient speed. But Andreas has explained that at length in
r.b.t.


--
MfG/Best regards
helmut springer panta rhei

[SMS]

Phil W Lee wrote:

>
> You haven't seen any modern ones then.
>> I wonder if you could couple the hub generator with an LED headlight and get
>> a decent illumination for riding at, say, 25 kph on an unlit roadway.
>
> Easily, and I can't think of any reason to do anything else.
> When you are providing the power, you don't want to waste it on
> inefficient lighting technologies like bits of hot wire.
> LEDs give the best bang for your buck, with better lumen/watt than
> even HID.

HID are far more efficient in lumens/watt.

But yes, there's no hot wire on LEDs, instead there's a very hot
semiconductor junction, with all the cooling challenges of
semiconductors. There is even active cooling available for LED lamps
now, because passive convection cooling can't keep up. Alas, nothing is
free. It was interesting to read the literature on the Edelux,
especially the part about the cooling.

Still, a 3W hub generator could sufficiently power a single 3W LED
headlight at moderate speed. Now all that needs to happen is for some
company in China to come out with such a headlight for $20, and it'll
enable a new generation of bicycle dynamo lighting. Certainly $212 LED
headlights aren't going to have a huge market.

The problem is that LED headlights aren't just an LED in place of a
filament bulb. The LED headlights require a switching regulator, you
can't drive them directly from the dynamo. The Edelux literature
mentions "very low loss" in their switching regulator but they aren't
more specific than that. The firt thing they must be doing is running
the output of the dynamo through a full wave bridge rectifier, which has
a maximum efficiency (with perfect diodes that don't exist) of 81.2%.
Then they're running the output through a DC-DC switching regulator,
which also has losses. By the time they're done. they probably only have
70% of the power remaining.

[SMS]

C.H. Luu wrote:
> This is one of the nicest ride you can do in the north bay. I usually
> head into the Marin headlans beforing going through Sausalito and then
> onto Larkspur.

Yes, Conzelman road is just wonderful, except when the park rangers
decide to give speeding tickets to cyclists on the one-way downhill
section. Riding through the tunnel is also fun, though now that it's
legal to go through it's less exciting than when the military police
would wait at the east end for bicyclists to ticket.

> The stretch of road between Tiburon and Larkspur is
> especially scenic and has little traffic. Granted it's our right to
> travel the roads, but it is rather dangerous at night.

I don't know where you get the idea that riding at night, with good
lighting, is any more dangerous that riding during the daytime. That
stretch is pretty narrow with no shoulder, and I tend to take the whole
lane a lot so if the vehicles want to go by they really have to pass,
not just squeeze me off the road. The Flash Flag helps a lot as well.

With good lights on a bicycle you really stand out at night, especially
on unlit roads. In the daytime is when you are less visible, though now
I see more and more cyclists with "DRLs" consisting of very bright LED
flashing headlights and taillights that are visible even in the daytime.

When you curse bicyclists while driving at night is when you almost hit
them because they have no lights, or the lights they have are so poor
that they aren't visible even with lights. It's just insane that these
people value their life so little that they're not spending $40 or so
for some good lights.

> I honestly don't think that this will get any better.

But it has gotten much better already. Bicycle lighting has evolved from
the days of lights that neither made a cyclist visible, nor lit up the
road well enough to ride at an expeditious rate.

> travel during daylight hours. If you must brave the darkness, be
> prepared to put your foot down at a moment's notice. I've ridden
> betweent the Pier area and the Presidio. Even in daylight, it's
> hazardous.

Between the single's Safeway (the pick-up spot for singles in the Marina
district) all the way to Fort Point it's a wide paved multi-use trail
with separate lanes for each direction of bicycles and pedestrians. Once
you enter the Presidio the traffic is very light and you don't even need
to use the trail if you don't want to.

Due to the fog, you really want to be using good lights even on full
moon nights.

I found it interesting that the biggest bicycle rental company down by
the wharf, Blazing Saddles, has a selling point of "Blazing Saddles
provide <sic> a 24 hour drop off area, so you can experience ultimate
fun, all day long, no time constraints!" That's great, especially with
the prices they charge for daily rentals, of $28-105 per day, since you
want to get your money's worth. But they really should provide equipment
that makes such riding legal.

[SMS]

Tom Sherman wrote:

> If it has manual door locks, crank windows, vinyl seats and a tractor
> engine (1980's Land Cruiser station wagon) is it really a SUV?

Cloth seats, crank windows, manual locks, and a Chevrolet straight-6
engine, manual locking hubs, and of course manual transmission.

[SMS]

Tom Sherman wrote:

> Could not a Cree 3W LED be driven by a 3W dynamo hub, or two 3W Crees by
> a 6W dynamo hub? Batteries do not cut it for certain people, such as
> those who like long night rides to avoid the worst of the summer heat.

Yes. Probably you could drive two 3W LEDs from a 3W hub if you were
going fast enough. The best option would be a hybrid system where the
dynamo charged a battery so you didn't waste excess generated power when
going fast, and could be at full brightness when slowing down. It would
also be good to have multiple brightness levels so you could select one
based on your needs.

[SMS]

Tom Sherman wrote:
> SMS aka Steven M. Scharf wrote:
>> Tom Sherman wrote:
>>
>>> If it has manual door locks, crank windows, vinyl seats and a tractor
>>> engine (1980's Land Cruiser station wagon) is it really a SUV?
>>
>> Cloth seats, crank windows, manual locks, and a Chevrolet straight-6
>> engine, manual locking hubs, and of course manual transmission.
>
> And of course, a transfer case and manually locking hubs.
>
Fix your computer's RTC Tom.

[Tom Sherman[_3_]]

SMS aka Steven M. Scharf wrote:
> Tom Sherman wrote:
>> SMS aka Steven M. Scharf wrote:
>>> Tom Sherman wrote:
>>>
>>>> If it has manual door locks, crank windows, vinyl seats and a
>>>> tractor engine (1980's Land Cruiser station wagon) is it really a SUV?
>>>
>>> Cloth seats, crank windows, manual locks, and a Chevrolet straight-6
>>> engine, manual locking hubs, and of course manual transmission.
>>
>> And of course, a transfer case and manually locking hubs.
>>
> Fix your computer's RTC Tom.

Hey, I am just so speedy that I am a day ahead. ;)

(I am using a new laptop that I picked up because it was on sale, in
stock and my desktop's power supply died and will likely not come back
from the repair shop for a couple of weeks). Two days in, and not a fan
of Vista.

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Tom Sherman[_3_]]

aka Jobst Brandt wrote:
> SMS who? wrote:
>
Steven M. Scharf?

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Helmut Springer]

Tom Sherman > wrote:
> Could not a Cree 3W LED be driven by a 3W dynamo hub,

Sure.

> or two 3W Crees by a 6W dynamo hub?

The hub generator isn't limited to 3W: it is limited to roughly
500mA which translates to 3W with the German standard consumers.
Per construction the dynamo is more or less a stable current
provider and will happily deliver 500mA and 6W with the respective
consumers and sufficient speed. Which for modern LED lights isn't
that fast, 15-20km/h. This has been discusses in rather detail in
r.b.t before.

--
MfG/Best regards
helmut springer panta rhei

[SMS]

Helmut Springer wrote:
> Tom Sherman > wrote:
>> Could not a Cree 3W LED be driven by a 3W dynamo hub,
>
> Sure.
>
>> or two 3W Crees by a 6W dynamo hub?
>
> The hub generator isn't limited to 3W: it is limited to roughly
> 500mA which translates to 3W with the German standard consumers.
> Per construction the dynamo is more or less a stable current
> provider and will happily deliver 500mA and 6W with the respective
> consumers and sufficient speed. Which for modern LED lights isn't
> that fast, 15-20km/h. This has been discusses in rather detail in
> r.b.t before.

Yes, it's like a constant current source, but variable voltage. This is
a blessing and a curse. The incandescent lamps need to have voltage
regulators, typically a zener diode, so they don't burn out at high
speeds from over-voltage, which wastes power. Putting two in series is
one way to avoid wasting power at higher speeds.

An LED lamp, with a switching regulator could be designed to also charge
a battery at higher speeds, rather than just waste the excess power as
heat to be dissipated through a heat sink, but that's more complexity,
and more weight to carry around.

[SMS]

Tom Sherman wrote:
> SMS aka Steven M. Scharf wrote:
>> Tom Sherman wrote:
>>
>>> If it has manual door locks, crank windows, vinyl seats and a tractor
>>> engine (1980's Land Cruiser station wagon) is it really a SUV?
>>
>> Cloth seats, crank windows, manual locks, and a Chevrolet straight-6
>> engine, manual locking hubs, and of course manual transmission.
>
> And of course, a transfer case and manually locking hubs.
>

I never got the PTO wench <sic>. I wonder if the new models even still
have that capability.

[SMS]

DennisTheBald wrote:

> If you're talking about banging some actual greenbacks then
> lead acid and halogen is your best bet.

Nah, you don't need serious greenbacks for lead acid and halogen. In
fact, I don't think you can get much cheaper than a 12V lead acid gelled
electrolyte battery and a 12 volt halogen lamp for a good commute
system, when you're not all that concerned about weight, and don't want
to spend much money.

The battery is $10-22 depending on the capacity you want at
"http://tinyurl.com/5sn7fd" and they're not even the cheapest source.

A 12 volt halogen headlamp varies in price. MR16 lamps have an excellent
beam pattern for cycling applications. You can get a set of two for $23
at "http://tinyurl.com/5as6aw" but you should replace the lamp with
something lower wattage like a 10W or 20W lamp.

I've also used 14W and 25W PAR36 sealed beams. They have a flood beam
pattern, and the large reflector really helps efficiency. See
"http://tinyurl.com/5mp63u". For some reason the PAR36 beams seem to get
more respect from vehicles during commuting. They may think that a
motorcycle is approaching, rather than a bicycle. These lights are not
blinding like HID lights. I don't even use an enclosure, these are
lightweight all plastic beams, and I mount them directly to an
insulator, then to the bike (on a quill stem bike use a steel reflector
bracket).

You can get a set of 55W driving lamps for less than $10 at Harbor
Freight, but the lowest wattage H3 bulbs are 25W, and cost $11.50 each.

You can get a lead-acid charger for $5 on sale from Harbor Freight.
"http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=42292".

Add a fuse and some wire, and you've got a very good commute systems for
well under $50, depending on the lamps and batteries you choose. You
can also power a xenon strobe off the same battery, and it's much more
visible than all but the best LED rear flashers.

Google "Bicycle Lighting" and click on "I'm Feeling Lucky." You'll go
straight to an amazing web site with a lot of information on DIY bicycle
lighting. OMG, that's my site!

[SMS]

wrote:
> SMS? wrote:
>
>>>> I owned an SUV before the term SUV was even coined (an old Toyota
>>>> Land Cruiser). I had to sell it once everyone had an SUV, or I
>>>> would be accused of being a conformist.
>
>>> Meh, who cares what the Jones think. Selling it to not look like a
>>> conformist is being a fashionista just as much as buying it to be a
>>> conformist.
>
>> Feh, that was a joke. I did sell it eventually because a vehicle that
>> got 11 city/13 highway, was impractical.
>
> So when did it start getting poor gas mileage and if that wasn't a
> change, why did you gt it in the first place if it wasn't to cloak
> yourself in truck driver ambience, the bulldog on the block?

That was the rated mileage. I bought it as a second car to be able to
take 5 people and gear cross country skiing. In 16 years, I put less
than 80K miles on it. Between the poor mileage and an excessive mount of
repairs, and no longer going on the types of trips where I needed such a
vehicle, when someone approached me and wanted to buy it, I got rid of
it. It was the most un-SUV like 4WD vehicle around, no power anything,
all manual, and an engine designed for high torque, not for highway driving.

[Tom Sherman[_3_]]

SMS aka Steven M. Scharf wrote:
> wrote:
>
>> Bicycling has been infested by a conformity similar to that of autos
>> (aka trucks and SUV's).
>
> There are still ample opportunities to not conform. Alas, the price of
> non-conformity is often a lot higher now than in the past.
> [...]

Recumbent bicycles are not that expensive!

> I owned an SUV before the term SUV was even coined (an old Toyota Land
> Cruiser). I had to sell it once everyone had an SUV, or I would be
> accused of being a conformist.

If it has manual door locks, crank windows, vinyl seats and a tractor
engine (1980's Land Cruiser station wagon) is it really a SUV?

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Tom Sherman[_3_]]

SMS aka Steven M. Scharf wrote:
> Helmut Springer wrote:
>> In rec.bicycles.misc SMS > wrote:
>>> The lights I find most annoying are those flashing LED bicycle
>>> lights and HID bicycle headlights. OTOH, the former does make the
>>> cyclist visible to motor vehicles in the daytime which is their
>>> goal,
>>
>> A flashing LED in bright daylight? Good one 8)
>
> Obviously you've never seen one of the Cree 3W LED flashing lights. They
> are extremely bright and visible in the daytime.
>
>> You could install a reasonable one if it wasn't against your deepest
>> believe 8)
>
> I've seen people with the so-called "decent" ones. They are not much
> better than the Union/Marwi. There is one supposedly really good one
> from SolidLights (it's gotten good reviews from dynamo light users) but
> it's like $300 just for the lamp.

Could not a Cree 3W LED be driven by a 3W dynamo hub, or two 3W Crees by
a 6W dynamo hub? Batteries do not cut it for certain people, such as
those who like long night rides to avoid the worst of the summer heat.

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Tom Sherman[_3_]]

SMS aka Steven M. Scharf wrote:
> Tom Sherman wrote:
>> SMS aka Steven M. Scharf wrote:
>>> Tom Sherman wrote:
>>>
>>>> If it has manual door locks, crank windows, vinyl seats and a
>>>> tractor engine (1980's Land Cruiser station wagon) is it really a SUV?
>>>
>>> Cloth seats, crank windows, manual locks, and a Chevrolet straight-6
>>> engine, manual locking hubs, and of course manual transmission.
>>
>> And of course, a transfer case and manually locking hubs.
>>
>
> I never got the PTO wench <sic>. I wonder if the new models even still
> have that capability.

Land Rover dropped the PTO from it vehicles, so you can no longer use
one to run farm equipment. :(

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Tom Sherman[_3_]]

Dane Buson wrote:
> Tom Sherman > wrote:
>> SMS aka Steven M. Scharf wrote:
>>> wrote:
>>>
>>>> Bicycling has been infested by a conformity similar to that of autos
>>>> (aka trucks and SUV's).
>>> There are still ample opportunities to not conform. Alas, the price of
>>> non-conformity is often a lot higher now than in the past.
>>> [...]
>> Recumbent bicycles are not that expensive!
>
> Now Tom, I thought we agreed we weren't going to talk about those in
> polite company?
>
> /me looks around
>
> Errrr, never mind, carry on.
>
Indeed! ;)

> Any recommendations for a tadpole trike? I'm getting tired of banging
> my hips during icy winter days.
>
USian made, and reasonably priced: <http://www.catrike.com/>.

High performance, good handling but still corrosion resistant:
<http://www.windcheetah.co.uk/>.

Rear suspension is nice, since it is hard to avoid potholes with all
three wheel tracks, and this one is also corrosion resistant:
<http://www.optima-cycles.nl/main/en/modellen/5.html?Itemid=27>.

Laugh at the cold rain: <http://leitra.dk/news.php>.

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Tom Sherman[_3_]]

SMS aka Steven M. Scharf wrote:
> Tom Sherman wrote:
>
>> If it has manual door locks, crank windows, vinyl seats and a tractor
>> engine (1980's Land Cruiser station wagon) is it really a SUV?
>
> Cloth seats, crank windows, manual locks, and a Chevrolet straight-6
> engine, manual locking hubs, and of course manual transmission.

And of course, a transfer case and manually locking hubs.

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Frank Krygowski[_2_]]

On Nov 25, 7:03*pm, DennisTheBald > wrote:
> On Nov 25, 11:50 am, Frank Krygowski > wrote:
>
>
>
> > On Nov 24, 3:45 pm, SMS > wrote:
>
> > > The problem is that LED headlights aren't just an LED in place of a
> > > filament bulb. The LED headlights require a switching regulator, you
> > > can't drive them directly from the dynamo.
>
> > I'm seriously curious about this point.
>
> > Almost all bike generators output 0.5 amp AC current. *They pump that
> > same current into any resistive load, within reason. *That's what
> > allows putting two 3W halogen headlamps in series with certain
> > generators. *The same 0.5 amps flows through both and lights them
> > both.
>
> > If the output is already regulated to 0.5 amps, and if LEDs require a
> > regulated current, why is a switching regulator needed? *For an LED
> > driven by a battery, of course a limiting resistor or complicated
> > constant current circuit is needed. *But it seems LED requirements
> > naturally match generator characteristics.
>
> > Online and in at least one magazine, I've seen circuits used by
> > experimenters to build their own LED headlights for generators.
> > Several simply ran the AC output through a bridge rectifier, then into
> > the LED. *One person skipped that, and just used two opposing LEDs,
> > with each functioning during half the AC cycle.
>
> > I briefly bench tested the latter scheme. *It seemed to work fine, but
> > mine was a very brief test.
>
> > Why do commercial LED lamps intended for generators need anything
> > more?
>
> > - Frank Krygowski
>
> I'm with ya here. *I want to know why the LEDs couldn't be the
> rectifier. *I guess if the voltage gets too high they turn into NEDs
> (noise emitting diodes, albeit single use), but couldn't we limit that
> with a battery instead of the more traditional resistor?

Looks to me like a fairly typical max reverse voltage is about 5
volts. If the two LEDs were in parallel, the forward one would dump
all the current at less than 5 volts.

If necessary, I suppose you could back them up with a standard diode
for more protection, but I'm not sure that's necessary.

I'm not an electrical engineer, but I wish a competent EE would
comment.

- Frank Krygowski

[Peter Cole[_2_]]

SMS wrote:
> wrote:
>
>> Here is what they advertise with blinding brightness. Watch that
>> light:
>>
>> http://www.xenonpros.com/?gclid=CMuAj7OcjpcCFQ89awod2C1DGA
>
> $200 for a bicycle light, ouch.

$55 for a flashlight -- ouch!


>
> If you want to carry something light that's sufficiently powerful for
> when you get caught out at night, look at:
>
> "http://eliteled.com/products/flashlights/fenix-l2d-q5.html"
> and
> "http://eliteled.com/products/accessory/fenix-bfm.html"
>
> It's got a beam pattern that's very good for cycling, both in terms of
> seeing and being seen, and it's got three brightness levels so you can
> avoid blinding people if you're in an area with a lot of oncoming
> bicycles on a narrow path.
>
> When the woman said "you're blinding me" we were on a narrow path in
> front of the Maritime museum at Aquatic park, and she was only about 18"
> to the left. This is not a typical situation with oncoming traffic. If
> both of us had had no lights then it would have been really bad!

Since you're using a flashlight, the beam is symmetrical (circular),
putting out "spill" light equally above and below the pointed direction.
I don't know about the Fenix, but most LED (and MR-16) lights have a
faceted (or "orange peel") reflector, used to diffuse the light to even
out hot spots. This causes considerable spill. An easy solution to the
problem would be to fit a hood on the front to cut off upward spill.

One of the things I like about head mounted lights is that they're easy
to dip to avoid blinding oncoming traffic. If you're feeling charitable
you can even point them ahead of the oncoming cyclist to illuminate
their path -- at least until they get by. They're also useful to
simulate a high beam flash to get oncoming motorists to dim theirs.

[Peter Cole[_2_]]

Tom Kunich wrote:
> "Helmut Springer" > wrote in message
> ...
>> In rec.bicycles.misc SMS > wrote:
>>> I have a dynamo light on the bike I was riding in San Francisco on
>>> Saturday night, and it was just a complete waste of perfectly good
>>> human power to use it.
>>
>> You could install a reasonable one if it wasn't against your deepest
>> believe 8)
>
> I have never seen a European type under-the-bottom-bracket generator
> being sold here Helmut.
>
> The kind available here are the side-of-the-tire kind that are very
> inefficient and scrub a lot.
>
> And of course the in-hub generators are the best of all. But none that
> I've seen generate sufficient power for a decent headlight that is
> effective at anything other than a dim glow that is supposed to alert
> drivers not to run you over.
>
> I wonder if you could couple the hub generator with an LED headlight and
> get a decent illumination for riding at, say, 25 kph on an unlit roadway.
>

I've ridden all night side-by-side with riders using very good hub
dynamos and lights. They work pretty well, a bit better than a good 2.5W
halogen like my Cateye micro's, but not as good as a 10W system. I'd
rate them adequate for normal night riding, maybe not quite so under bad
conditions (lots of oncoming glare, rain, etc.).

A good LED head on a good dynamo should be a large improvement, in
absolute amount of light, efficiency, ruggedness, and eventually, cost.
But all that is pretty well known to dynamo users.

[Edward Dolan]

"Tom Sherman" > wrote in message
...
[...]
> USian made, and reasonably priced: <http://www.catrike.com/>.

Ugh! I go to the Catrike website and the first thing I see is a picture of
old Larry Varney linked to his review on BROL. Why hasn't that old Kentucky
coot croaked by now? Anyone who bases a decision on a review of his has got
to be nuts. Larry Varney couldn't think his way out of a paper bag. I see he
still has his Santa Claus beard. What an ugly freak he is!

> High performance, good handling but still corrosion resistant:
> <http://www.windcheetah.co.uk/>.

You bet, just take all your money out of the bank and give it to these
assholes.
[...]

Regards,

Ed Dolan the Great - Minnesota
aka
Saint Edward the Great - Order of the Perpetual Sorrows - Minnesota

[Peter Cole[_2_]]

SMS wrote:
> Helmut Springer wrote:
>> Tom Kunich <cyclintom@yahoo. com> wrote:
>>> I have never seen a European type under-the-bottom-bracket
>>> generator being sold here Helmut.
>>
>> Those have decreased quite a lot here by now...in-hub generators
>> have pretty much taken over that market segment.
>
> Can you even buy the bottom bracket dynamos anymore? I have an old Sanyo
> that still works, but I haven't seen that type for sale anywhere in the
> world for a long time.
>
>> IMO yes: at that speed you can easily power 2 or 3 headlights with
>> 3W LED if you wanted. With recent models like Schmidt's Edelux or
>> B&M's Cyo Sport it has become easier, and technology robably won't
>> stop there.
>
> I doubt if you could three 3W LED headlights with a 3W dynamo. Two might
> be do-able at high speeds.

Sure you could. At ~$6/LED you'd just be spending more than you need to.
Power LED's are more efficient at less than full power.


> These LED headlights waste a lot of power as
> heat, as well as wasting some in the drive circuitry and regulation
> circuitry.

LED's waste less power as heat than incandescents (that's why you get
more lumens/watt). You don't need regulation driving LED's from a dynamo
(as several have demonstrated), they're a good match as is.


> "Efficiency and LED lifetime mainly depend on its cooling. This is why
> we placed the LED on a massive copper heat sink, which in turn conducts
> the heat to the aluminum housing, and then to the outside air. At high
> speed the good cooling allows for an increase of 20% luminous flux
> compared to usual LED headligts, some of which can reach more than 100°
> Celsius (210° F)."

Aluminum is the standard heat sink material for power electronics,
copper is just a bit of hype. Heat sinking is nothing new. All you need
is an aluminum light housing, finned if necessary. Check out the LED
MR-16 lights.


> Of course the other issue with the Edelux is that not many people are
> going to spending $212 on just a headlight.

This is $20-30 technology (currently), only the bike business gives it
such obscene markups.

[Peter Cole[_2_]]

SMS wrote:
> Phil W Lee wrote:
>
>>
>> You haven't seen any modern ones then.
>>> I wonder if you could couple the hub generator with an LED headlight
>>> and get a decent illumination for riding at, say, 25 kph on an unlit
>>> roadway.
>>
>> Easily, and I can't think of any reason to do anything else.
>> When you are providing the power, you don't want to waste it on
>> inefficient lighting technologies like bits of hot wire.
>> LEDs give the best bang for your buck, with better lumen/watt than
>> even HID.
>
> HID are far more efficient in lumens/watt.


Currently, it's roughly a tie. In actual products, HID's may still have
a slight edge, perhaps 50-60 l/W vs. 80-90 l/W, but at peak efficiency,
LED's are above 100 l/W. The problem with HID lamps is making them
small. You don't really need more than 150-300 lumen for bike use, which
translates to a HID lamp of 3-4W. You can't easily make them that small.


> But yes, there's no hot wire on LEDs, instead there's a very hot
> semiconductor junction, with all the cooling challenges of
> semiconductors. There is even active cooling available for LED lamps
> now, because passive convection cooling can't keep up. Alas, nothing is
> free. It was interesting to read the literature on the Edelux,
> especially the part about the cooling.

Active cooling can make sense where space is limited, but passive
cooling a 3-5W thermal load is not very hard.


> Still, a 3W hub generator could sufficiently power a single 3W LED
> headlight at moderate speed. Now all that needs to happen is for some
> company in China to come out with such a headlight for $20, and it'll
> enable a new generation of bicycle dynamo lighting. Certainly $212 LED
> headlights aren't going to have a huge market.
>
> The problem is that LED headlights aren't just an LED in place of a
> filament bulb. The LED headlights require a switching regulator, you
> can't drive them directly from the dynamo.

Sure you can.

The Edelux literature
> mentions "very low loss" in their switching regulator but they aren't
> more specific than that. The firt thing they must be doing is running
> the output of the dynamo through a full wave bridge rectifier, which has
> a maximum efficiency (with perfect diodes that don't exist) of 81.2%.
> Then they're running the output through a DC-DC switching regulator,
> which also has losses. By the time they're done. they probably only have
> 70% of the power remaining.

Again, your efficiency figure for a FW bridge is wrong, but we've been
all over that.

[Peter Cole[_2_]]

SMS wrote:
> Tom Sherman wrote:
>
>> Could not a Cree 3W LED be driven by a 3W dynamo hub, or two 3W Crees
>> by a 6W dynamo hub? Batteries do not cut it for certain people, such
>> as those who like long night rides to avoid the worst of the summer heat.
>
> Yes. Probably you could drive two 3W LEDs from a 3W hub if you were
> going fast enough. The best option would be a hybrid system where the
> dynamo charged a battery so you didn't waste excess generated power when
> going fast, and could be at full brightness when slowing down. It would
> also be good to have multiple brightness levels so you could select one
> based on your needs.

All you need to do is to design you light so that peak dynamo power
doesn't exceed LED power rating. The simple way is to just over-spec the
LED a bit (or use multiples). I can't see why you wouldn't want more
light the faster you're going. At low power/speed the LED wins because
the color stays constant and the efficiency only improves. Batteries are
less necessary with an LED head than an incandescent one. LED's are a
prefect match to a dynamo source without any other complexity.

[Peter Cole[_2_]]

Frank Krygowski wrote:
> On Nov 25, 7:03 pm, DennisTheBald > wrote:
>> On Nov 25, 11:50 am, Frank Krygowski > wrote:
>>
>>
>>
>>> On Nov 24, 3:45 pm, SMS > wrote:
>>>> The problem is that LED headlights aren't just an LED in place of a
>>>> filament bulb. The LED headlights require a switching regulator, you
>>>> can't drive them directly from the dynamo.
>>> I'm seriously curious about this point.
>>> Almost all bike generators output 0.5 amp AC current. They pump that
>>> same current into any resistive load, within reason. That's what
>>> allows putting two 3W halogen headlamps in series with certain
>>> generators. The same 0.5 amps flows through both and lights them
>>> both.
>>> If the output is already regulated to 0.5 amps, and if LEDs require a
>>> regulated current, why is a switching regulator needed? For an LED
>>> driven by a battery, of course a limiting resistor or complicated
>>> constant current circuit is needed. But it seems LED requirements
>>> naturally match generator characteristics.
>>> Online and in at least one magazine, I've seen circuits used by
>>> experimenters to build their own LED headlights for generators.
>>> Several simply ran the AC output through a bridge rectifier, then into
>>> the LED. One person skipped that, and just used two opposing LEDs,
>>> with each functioning during half the AC cycle.
>>> I briefly bench tested the latter scheme. It seemed to work fine, but
>>> mine was a very brief test.
>>> Why do commercial LED lamps intended for generators need anything
>>> more?
>>> - Frank Krygowski
>> I'm with ya here. I want to know why the LEDs couldn't be the
>> rectifier. I guess if the voltage gets too high they turn into NEDs
>> (noise emitting diodes, albeit single use), but couldn't we limit that
>> with a battery instead of the more traditional resistor?
>
> Looks to me like a fairly typical max reverse voltage is about 5
> volts. If the two LEDs were in parallel, the forward one would dump
> all the current at less than 5 volts.
>
> If necessary, I suppose you could back them up with a standard diode
> for more protection, but I'm not sure that's necessary.
>
> I'm not an electrical engineer, but I wish a competent EE would
> comment.
>
> - Frank Krygowski

Some LED spec sheets caution to never reverse bias the devices, some
don't. It would probably work with many devices as you describe.

[Frank Krygowski[_2_]]

On Nov 26, 8:54*am, Peter Cole > wrote:
>
>
> Since you're using a flashlight, the beam is symmetrical (circular),
> putting out "spill" light equally above and below the pointed direction.

True. This is why a road lamp should have optics designed for the
job.

> I don't know about the Fenix, but most LED (and MR-16) lights have a
> faceted (or "orange peel") reflector, used to diffuse the light to even
> out hot spots. This causes considerable spill. An easy solution to the
> problem would be to fit a hood on the front to cut off upward spill.

It's not necessarily so easy. Depending on the source and optics,
shading the top half of the lamp may do little more than dim the
entire beam. IOW, with some lamps, even the bottom half of the lamp
generates a lot of upwards scatter.

- Frank Krygowski

[SMS]

Peter Cole wrote:
> SMS wrote:
>> wrote:
>>
>>> Here is what they advertise with blinding brightness. Watch that
>>> light:
>>>
>>> http://www.xenonpros.com/?gclid=CMuAj7OcjpcCFQ89awod2C1DGA
>>
>> $200 for a bicycle light, ouch.
>
> $55 for a flashlight -- ouch!

Yeah, I agree. It seems like a lot until you compare it with the cost of
bicycle lights that illuminate as well.

You can always get the $30 Lowe's Task Force flashlight which has become
like a cult item around here.

[Frank Krygowski[_2_]]

On Nov 26, 9:01*am, Peter Cole > wrote:
>
> I've ridden all night side-by-side with riders using very good hub
> dynamos and lights. They work pretty well, a bit better than a good 2.5W
> halogen like my Cateye micro's, but not as good as a 10W system.

It definitely depends on the system.

The incident that awakened me to the importance of optics was this:
My best friend decided to join me in night riding, so he shelled out
for a 10 watt system that was on sale somewhere. Sorry, I don't
remember the brand, but it was a typical moderately pricey system of
the day, with a small sealed lead-acid gel cell, wall-wart charger,
and headlamp. The generator I was using at the time was a Sanyo
bottom bracket unit, which I now know is a bit low on output power
(details on request). Anyway, we certainly expected his well-over-
$100 system to be greatly superior to my 2.4 watt headlight.

It wasn't even close. I'm sure his system threw out more lumens, but
the optics were so terrible that he couldn't ride more than about 8
mph in comfort. We could see dim light being scattered everywhere,
including way up into the trees; but there was no practical
illumination of the road. I believe he used that system only once or
twice, then left it on the bench until the battery eventually died.

Other 10 W halogen systems with better optics may be excellent; but I
don't know of one that actually has good road optics. Most are
designed for mountain biking.

- Frank Krygowski

[Dane Buson]

Tom Sherman > wrote:
> Dane Buson wrote:
>> Tom Sherman > wrote:

>>> Recumbent bicycles are not that expensive!
>>
>> Now Tom, I thought we agreed we weren't going to talk about those in
>> polite company?
>>
>> /me looks around
>>
>> Errrr, never mind, carry on.
>>
> Indeed! ;)
>
>> Any recommendations for a tadpole trike? I'm getting tired of banging
>> my hips during icy winter days.
>
> USian made, and reasonably priced: <http://www.catrike.com/>.

Possible, but since I'd only rarely be riding it, still too much cash.
Admittedly I knew that before I even asked the question. I guess it's
time to pick up some Atomic Zombie books.

> High performance, good handling but still corrosion resistant:
> <http://www.windcheetah.co.uk/>.

Hmm, did I mention I want a trike, not to establish an annuity for their
grandchildren?

> Rear suspension is nice, since it is hard to avoid potholes with all
> three wheel tracks, and this one is also corrosion resistant:
> <http://www.optima-cycles.nl/main/en/modellen/5.html?Itemid=27>.
>
> Laugh at the cold rain: <http://leitra.dk/news.php>.

Which should be nicely balanced by the people laughing at you. I'm fine
with a regular trike, but the enclosed ones turn the dork factor up to
11. Not to mention I cross multiple bridges with *high* winds at times.

--
Dane Buson -
Anyone who cannot cope with mathematics is not fully human. At best he
is a tolerable subhuman who has learned to wear shoes, bathe and not
make messes in the house.
-- Lazarus Long, "Time Enough for Love"

[DennisTheBald]

On Nov 25, 7:28 pm, SMS > wrote:
> DennisTheBald wrote:
> > If you're talking about banging some actual greenbacks then
> > lead acid and halogen is your best bet.
>
> Nah, you don't need serious greenbacks for lead acid and halogen. In
> fact, I don't think you can get much cheaper than a 12V lead acid gelled
> electrolyte battery and a 12 volt halogen lamp for a good commute
> system, when you're not all that concerned about weight, and don't want
> to spend much money.
>
> The battery is $10-22 depending on the capacity you want at
> "http://tinyurl.com/5sn7fd" and they're not even the cheapest source.
>
> A 12 volt halogen headlamp varies in price. MR16 lamps have an excellent
> beam pattern for cycling applications. You can get a set of two for $23
> at "http://tinyurl.com/5as6aw" but you should replace the lamp with
> something lower wattage like a 10W or 20W lamp.
>
> I've also used 14W and 25W PAR36 sealed beams. They have a flood beam
> pattern, and the large reflector really helps efficiency. See
> "http://tinyurl.com/5mp63u". For some reason the PAR36 beams seem to get
> more respect from vehicles during commuting. They may think that a
> motorcycle is approaching, rather than a bicycle. These lights are not
> blinding like HID lights. I don't even use an enclosure, these are
> lightweight all plastic beams, and I mount them directly to an
> insulator, then to the bike (on a quill stem bike use a steel reflector
> bracket).
>
> You can get a set of 55W driving lamps for less than $10 at Harbor
> Freight, but the lowest wattage H3 bulbs are 25W, and cost $11.50 each.
>
> You can get a lead-acid charger for $5 on sale from Harbor Freight.
> "http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=42292".
>
> Add a fuse and some wire, and you've got a very good commute systems for
> well under $50, depending on the lamps and batteries you choose. You
> can also power a xenon strobe off the same battery, and it's much more
> visible than all but the best LED rear flashers.
>
> Google "Bicycle Lighting" and click on "I'm Feeling Lucky." You'll go
> straight to an amazing web site with a lot of information on DIY bicycle
> lighting. OMG, that's my site!

yeah, that's what I'm saying, lumens per watt may be higher with LEDs,
but if the conversation is lumens per buck then lead acid/halogen is
the real deal. And you're a commuter, not some weight wennie
recreational racer... hauling around a 7-12amp hour gel cell ain't no
big deal to the pannier toting set.

I'm using 36W halogen bulbs, the difference in the amount of light
isn't that severe between them and regular 55W headlights, but my burn
time would be about 50% less with the same battery. I've been using
these things since way bay in the 90's when I rode a wedgie. But I do
have an enclosure - I bought a running lights kit, cost less that $20,
came with 36W bulbs, included a switch and a chunk of wire (of course
the instructions were grounding thru the body) and the lens does a
really good job of focusing the light where I want it.

I like a flashing zenon light too... the coast guard approved single D
cell number will slide down the rails of most wedgie saddles quite
nicely. I'd like to find a source of those zenon lights they mount on
the top of the school buses.

You can't touch this setup with stuff from the bike shop, even big
buck stuff. And this time of year, wrap yer rear rack with blinking
Christmas lights just to be festive, why not you've got plenty of
juice to spare.

I wouldn't rule out switching over to a hub generator / LED combo at
some point, like after I win the lottery or something.

[Dane Buson]

SMS > wrote:
> Dane Buson wrote:
>
>> It sounds like rather too much frippery (the battery anyway). It would
>> add expense weight and energy loss for very little real return.
>
> On the good dynamo powered LED lights, with switching regulators, you
> already have the loss (technically there's no such thing as energy loss,
> you're just converting more of the energy to heat through the
> regulator).

Eh, with the battery you're getting double conversion losses (charging
in and taking out), plus leakage when it's not being used. In addition
the expense of replacing the battery when it dies, which is part of the
whole point of a dynamo setup is not worrying about that sort of thing.

You'd have to setup some sort of matrix and figure out the cost/benefit,
but I suspect it's not as good as you'd think.

>What's happening is that when you're going fast, rather than
> burning out the LED due to too high a voltage, is that you're just
> wasting that power. You have the same issue with over-voltage protected
> incandescent dynamo lamps.

Eh, if after my 6 watts of LEDs are saturated they give off 2 watts of
heat, I don't really care. This is about having usable always available
lighting, this is not a min/maxing D&D session.

>> The multiple brightness levels would be nice admittedly.

>
> Yes, and the levels would not be based on the speed of the bicycle.

No actually that part is great. My problem is when I'm on bike paths
versus roads and don't want to blind other cyclists. I've never had any
problems because my light is dimmer when I'm slower, brighter when I'm
faster.

> You could also choose to charge the batteries in the daytime from the
> dynamo, with lights off, and if you really wanted to get fancy, only
> engage the charger during downhill runs, where the drag wouldn't matter.

Your solution is way too complicated (and yes that is a valid
engineering critique). KISS - You're adding cost and points of failure
for dubious to neglible benefit.

--
Dane Buson -
"I don't have to take this abuse from you -- I've got hundreds of
people waiting to abuse me."
-- Bill Murray, "Ghostbusters"

[Dane Buson]

SMS > wrote:
> Dane Buson wrote:
>
>> Also, with the better exchange rate, the very nice 2.4 W Busch & Muller
>> Topal LED Dynamo Headlamp is only $52.
>>
>> http://www.sjscycles.co.uk/product.asp?pf_id=12041&src=froogleUS&currency=USDa
>
> OMG, so someone did do an LED front light with no regulator circuitry,
> "Busch & Muller Topal LED Dynamo Headlamp 2.4W for hub dynamo (requires
> back light to be used).

Eh, it doesn't say explicitly it has no regulator (it probably does). They are
just (typically German-like) mandating a particular configuration. All in all,
what do you want for $50?

> Uh, so let's see how long that LED lasts going down a hill at 40MPH. Of
> course you'd never do such a foolish thing with a 2.4W headlamp like
> that, so it's self-limiting. And what if your rear light burns out or
> becomes disconnected?

2.4 watts of well focused LED? I've gone faster with less light. I'm
sure it's actually probably pretty good.

> The IQ Cyo senso plus states that 7.5 V must not be exceeded, so watch
> out there as well.

Meh, again, it's probably just arse-covering. I'll look for reviews in
six months and see if it's the cat's pajamas, or a steaming pile.

--
Dane Buson -
"God is my co-pilot but we crashed in the mountains and I had to eat him."
- Zakath - As seen on /.

[DennisTheBald]

On Nov 26, 10:20 am, Frank Krygowski > wrote:
> On Nov 26, 9:01 am, Peter Cole > wrote:
>
>
>
> > I've ridden all night side-by-side with riders using very good hub
> > dynamos and lights. They work pretty well, a bit better than a good 2.5W
> > halogen like my Cateye micro's, but not as good as a 10W system.
>
> It definitely depends on the system.
>
> The incident that awakened me to the importance of optics was this:
> My best friend decided to join me in night riding, so he shelled out
> for a 10 watt system that was on sale somewhere. Sorry, I don't
> remember the brand, but it was a typical moderately pricey system of
> the day, with a small sealed lead-acid gel cell, wall-wart charger,
> and headlamp. The generator I was using at the time was a Sanyo
> bottom bracket unit, which I now know is a bit low on output power
> (details on request). Anyway, we certainly expected his well-over-
> $100 system to be greatly superior to my 2.4 watt headlight.
>
> It wasn't even close. I'm sure his system threw out more lumens, but
> the optics were so terrible that he couldn't ride more than about 8
> mph in comfort. We could see dim light being scattered everywhere,
> including way up into the trees; but there was no practical
> illumination of the road. I believe he used that system only once or
> twice, then left it on the bench until the battery eventually died.
>
> Other 10 W halogen systems with better optics may be excellent; but I
> don't know of one that actually has good road optics. Most are
> designed for mountain biking.
>
> - Frank Krygowski

yeah, that's why you want to get the light kit from the autoparts
store, to get the lens that throws the light up the road instead of
into the ditch.

[Dane Buson]

Peter Cole > wrote:
> Tom Kunich wrote:
>>
>> And of course the in-hub generators are the best of all. But none that
>> I've seen generate sufficient power for a decent headlight that is
>> effective at anything other than a dim glow that is supposed to alert
>> drivers not to run you over.

Pfft. I've had people tell me they thought I was a car or a motorcycle
coming up behind them. Not exactly a dim glow.

>> I wonder if you could couple the hub generator with an LED headlight and
>> get a decent illumination for riding at, say, 25 kph on an unlit roadway.

I've maxed out at about 72 kph personally. I tend not to go quite as
fast at night.

> I've ridden all night side-by-side with riders using very good hub
> dynamos and lights. They work pretty well, a bit better than a good 2.5W
> halogen like my Cateye micro's, but not as good as a 10W system. I'd
> rate them adequate for normal night riding, maybe not quite so under bad
> conditions (lots of oncoming glare, rain, etc.).
>
> A good LED head on a good dynamo should be a large improvement, in
> absolute amount of light, efficiency, ruggedness, and eventually, cost.
> But all that is pretty well known to dynamo users.

It is rather nice. I got tired of replacing rechargeable lights when
the batteries died or connections corroded. The dynamo lights are
universally more durable and better sealed, even the crap ones.

--
Dane Buson -
It is by Perl alone I set my mind in motion. It is by the regex of Larry
that the code acquires flexibility, the flexibility enables obscurity, the
obscurity generates a warning. It is by Perl alone I set my mind in motion.
--Calle Dybedahl, in the Scary Devil Monastery

[SMS]

DennisTheBald wrote:

> yeah, that's what I'm saying, lumens per watt may be higher with LEDs,
> but if the conversation is lumens per buck then lead acid/halogen is
> the real deal. And you're a commuter, not some weight wennie
> recreational racer... hauling around a 7-12amp hour gel cell ain't no
> big deal to the pannier toting set.

I used to use the 6.5AH or 7AH, but for a 1 hour commute with a 14W 12V
headlamp, a smaller battery is fine, i.e. a 2.2AH.

> I wouldn't rule out switching over to a hub generator / LED combo at
> some point, like after I win the lottery or something.

Dynamo hubs are now being manufactured by more suppliers so costs will
come down, especially as part of complete bicycles. As after-market
add-ons they'll still be a lot due to the cost of a new wheel, as well
as mark-ups down the supply chain.

[Tom Sherman[_3_]]

DennisTheBald wrote:
> [...]
> I'm using 36W halogen bulbs, the difference in the amount of light
> isn't that severe between them and regular 55W headlights, but my burn
> time would be about 50% less with the same battery. I've been using
> these things since way bay in the 90's when I rode a wedgie. But I do
> have an enclosure - I bought a running lights kit, cost less that $20,
> came with 36W bulbs, included a switch and a chunk of wire (of course
> the instructions were grounding thru the body) and the lens does a
> really good job of focusing the light where I want it.
>
I like the idea of a 36W HID for my bicycle.

> I like a flashing zenon light too... the coast guard approved single D
> cell number will slide down the rails of most wedgie saddles quite
> nicely. I'd like to find a source of those zenon lights they mount on
> the top of the school buses.
>
Top of a school bus? Take a portable ladder and battery powered angle
grinder with a cutting wheel. ;)

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Tom Keats]

In article >,
Frank Krygowski > writes:
> On Nov 25, 2:41*pm, SMS > wrote:
>> Dane Buson wrote:
>> > Also, with the better exchange rate, the very nice 2.4 W Busch & Muller
>> > Topal LED Dynamo Headlamp is only $52.
>>
>> >http://www.sjscycles.co.uk/product.asp?pf_id=12041&src=froogleUS&curr...
>>
>> OMG, so someone did do an LED front light with no regulator circuitry,
>> "Busch & Muller Topal LED Dynamo Headlamp 2.4W for hub dynamo (requires
>> back light to be used).
>>
>> Uh, so let's see how long that LED lasts going down a hill at 40MPH.
> You mean, when the generator is putting out 0.5 amp at 40 mph...
> ... as opposed to when the generator is putting out 0.5 amp at 15
> mph? Hmm.
> Study http://www.m-gineering.nl/son12vg.htm and meditate on "constant
> current."

I'm not so sure I'd want to bomb down a hill at 40 MPH in
nighttime conditions with /any/ sort of lighting system.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[Helmut Springer]

In rec.bicycles.misc SMS > wrote:
>> I wouldn't rule out switching over to a hub generator / LED combo
>> at some point, like after I win the lottery or something.
>
> Dynamo hubs are now being manufactured by more suppliers so costs
> will come down,

The cheapest Shimano goes at 24EUR retail here, even low cost
department store everyday bicycles tend to feature something like
that. Any everyday bicycle above 800EUR has one for sure, above
1000EUR you'll typically have a very decent Shimano and LEDs.
People like simple and carefree equipment...

--
MfG/Best regards
helmut springer panta rhei

[Peter Cole[_2_]]

Frank Krygowski wrote:
> On Nov 26, 9:01 am, Peter Cole > wrote:
>> I've ridden all night side-by-side with riders using very good hub
>> dynamos and lights. They work pretty well, a bit better than a good 2.5W
>> halogen like my Cateye micro's, but not as good as a 10W system.
>
> It definitely depends on the system.
>
> The incident that awakened me to the importance of optics was this:
> My best friend decided to join me in night riding, so he shelled out
> for a 10 watt system that was on sale somewhere. Sorry, I don't
> remember the brand, but it was a typical moderately pricey system of
> the day, with a small sealed lead-acid gel cell, wall-wart charger,
> and headlamp. The generator I was using at the time was a Sanyo
> bottom bracket unit, which I now know is a bit low on output power
> (details on request). Anyway, we certainly expected his well-over-
> $100 system to be greatly superior to my 2.4 watt headlight.
>
> It wasn't even close. I'm sure his system threw out more lumens, but
> the optics were so terrible that he couldn't ride more than about 8
> mph in comfort. We could see dim light being scattered everywhere,
> including way up into the trees; but there was no practical
> illumination of the road. I believe he used that system only once or
> twice, then left it on the bench until the battery eventually died.
>
> Other 10 W halogen systems with better optics may be excellent; but I
> don't know of one that actually has good road optics. Most are
> designed for mountain biking.
>
> - Frank Krygowski
>

http://www.myra-simon.com/bike/schmidt.html

"Fourth was a VistaLite 500 lighting head with a 10W MR-11 bulb. This
was better than the Lumotec/Schmidt setup in all respects. The central
area was brighter, the dimmer area off to the sides was useful in seeing
what was going on at the sides of the road, and the beam was smoother
and whiter than my Lumotec/Schmidt setup. "

[Peter Cole[_2_]]

Frank Krygowski wrote:
> On Nov 26, 8:54 am, Peter Cole > wrote:
>>
>> Since you're using a flashlight, the beam is symmetrical (circular),
>> putting out "spill" light equally above and below the pointed direction.
>
> True. This is why a road lamp should have optics designed for the
> job.
>
>> I don't know about the Fenix, but most LED (and MR-16) lights have a
>> faceted (or "orange peel") reflector, used to diffuse the light to even
>> out hot spots. This causes considerable spill. An easy solution to the
>> problem would be to fit a hood on the front to cut off upward spill.
>
> It's not necessarily so easy. Depending on the source and optics,
> shading the top half of the lamp may do little more than dim the
> entire beam. IOW, with some lamps, even the bottom half of the lamp
> generates a lot of upwards scatter.

I tried it on a smooth reflector 1W LED light and it worked very well.
The high intensity LED lights tend to have small (~1") reflectors, so it
wouldn't take much of a hood to block the ray path from the entire
reflector above a cutoff level. If the hood was reflective on the inside
surface it would put the blocked light back to the road. With a very
diffuse (orange peel) reflector you might still have a little spill
upwards, but it would still be a big improvement over a plain
symmetrical reflector/source.

[Frank Krygowski[_2_]]

On Nov 27, 8:14*am, Peter Cole > wrote:
> Frank Krygowski wrote:
> > On Nov 26, 9:01 am, Peter Cole > wrote:
> >> I've ridden all night side-by-side with riders using very good hub
> >> dynamos and lights. They work pretty well, a bit better than a good 2.5W
> >> halogen like my Cateye micro's, but not as good as a 10W system.
>
> > It definitely depends on the system.
>
> > The incident that awakened me to the importance of optics was this:
> > My best friend decided to join me in night riding, so he shelled out
> > for a 10 watt system that was on sale somewhere. *Sorry, I don't
> > remember the brand, but it was a typical moderately pricey system of
> > the day, with a small sealed lead-acid gel cell, wall-wart charger,
> > and headlamp. *The generator I was using at the time was a Sanyo
> > bottom bracket unit, which I now know is a bit low on output power
> > (details on request). *Anyway, we certainly expected his well-over-
> > $100 system to be greatly superior to my 2.4 watt headlight.
>
> > It wasn't even close. *I'm sure his system threw out more lumens, but
> > the optics were so terrible that he couldn't ride more than about 8
> > mph in comfort. *We could see dim light being scattered everywhere,
> > including way up into the trees; but there was no practical
> > illumination of the road. *I believe he used that system only once or
> > twice, then left it on the bench until the battery eventually died.
>
> > Other 10 W halogen systems with better optics may be excellent; but I
> > don't know of one that actually has good road optics. *Most are
> > designed for mountain biking.
>
> > - Frank Krygowski
>
> http://www.myra-simon.com/bike/schmidt.html
>
> "Fourth was a VistaLite 500 lighting head with a 10W MR-11 bulb. This
> was better than the Lumotec/Schmidt setup in all respects. The central
> area was brighter, the dimmer area off to the sides was useful in seeing
> what was going on at the sides of the road, and the beam was smoother
> and whiter than my Lumotec/Schmidt setup. "

When I say "good road optics" I include the ability to not blind
oncoming vehicle operators, and not to waste light in unproductive
directions.

All headlights truly designed for the road feature a cutoff to limit
upward waste and direct those lumens where they'll do some good.. No
MR-series bulb has that.

- Frank Krygowski

[SMS]

Peter Cole wrote:

> I tried it on a smooth reflector 1W LED light and it worked very well.
> The high intensity LED lights tend to have small (~1") reflectors, so it
> wouldn't take much of a hood to block the ray path from the entire
> reflector above a cutoff level. If the hood was reflective on the inside
> surface it would put the blocked light back to the road. With a very
> diffuse (orange peel) reflector you might still have a little spill
> upwards, but it would still be a big improvement over a plain
> symmetrical reflector/source.

The symmetrical beam is not a problem. Look at the beam pattern when the
light is properly aimed. The center spot illuminates the road directly
ahead, while the flood provides a "being seen" light that is not blinding.

"http://i34.tinypic.com/2enls0x.jpg"

The same bike has a dynamo light which is much less useful because the
beam is only a "being seen light" and doesn't provide good illumination
for seeing the road. Admittedly it isn't a $200 or $300 LED dynamo lamp!

What I could do, is to build a switcher that could drive the LED
flashlight lamp from the dynamo. It's require a bridge rectifier, some
capacitors, and a buck boost switching regulator. I calculated the
losses of the conversion at about 30% minimum, using best case, ideal
components (it's probably closer to 40%), but it's an answer to a
problem that I don't have! Sticking in some Sanyo Eneloop recharageables
is not a problem. Now if I was doing randonneuring, I'd certainly go the
all-dymano route somehow.

The reason that the woman said "you're blinding me" last Saturday
evening is because she was coming almost directly toward me on a narrow
path. Normally an oncoming rider or vehicle would not be looking
straight-on into the center part of the beam. What I normally do on
bicycle trails is to go to a lower brightness if there is oncoming
traffic. Like most higher end LED lights, this light is digitally
regulated, and it has 4 different settings (9, 40, 80, 135 lumens) as
well as two flashing modes (strobe and S.O.S.). I just didn't see anyone
else coming because no one had lights. If these riders want to be
treated courteously by other riders (and most regular night riders do
have very good lights) then they need to get with the plan and have
lights themselves. That's why the rental place should offer them.

BTW, do any of the dynamo LED lights have brightness that's adjustable
in any way when you're riding fast enough that you might not need full
brightness? Once you add the switching regulator you eliminate the
problem of over-voltaging the LED and burning it out
(though you're bleeding off the excess power of the dynamo as heat).
It's just ridiculous to have the risk of burning out some of those
cheaper (but still costly) LED headlamps if the tail light burns out, or
if you go fast enough that you over-voltage/over-current it. Some of
these designers better go back and read Ohm's law again when it comes to
the relationship of voltage, resistance, and current, and not cheap out
when it comes to some simple over-voltage protection.

[Peter Cole[_2_]]

Frank Krygowski wrote:
> On Nov 27, 8:14 am, Peter Cole > wrote:

>> http://www.myra-simon.com/bike/schmidt.html
>>
>> "Fourth was a VistaLite 500 lighting head with a 10W MR-11 bulb. This
>> was better than the Lumotec/Schmidt setup in all respects. The central
>> area was brighter, the dimmer area off to the sides was useful in seeing
>> what was going on at the sides of the road, and the beam was smoother
>> and whiter than my Lumotec/Schmidt setup. "
>
> When I say "good road optics" I include the ability to not blind
> oncoming vehicle operators, and not to waste light in unproductive
> directions.
>
> All headlights truly designed for the road feature a cutoff to limit
> upward waste and direct those lumens where they'll do some good.. No
> MR-series bulb has that.

No, but I don't think anybody is designing new lights around MR
(multifaceted reflector) anymore. The reflector on those is designed to
diffuse the beam to avoid hot spots. LED's have much more compact
emitters, and even those that use a textured reflector diffuse the beam
much less.

I really think the only thing necessary to adapt a symmetrical beam like
those from a flashlight or MTB light is to just put a small hood on it.
Fresnel type lenses can shape the beam, but they tend to introduce
artifacts, too.

[Peter Cole[_2_]]

SMS wrote:

> What I could do, is to build a switcher that could drive the LED
> flashlight lamp from the dynamo. It's require a bridge rectifier, some
> capacitors, and a buck boost switching regulator. I calculated the
> losses of the conversion at about 30% minimum, using best case, ideal
> components (it's probably closer to 40%), but it's an answer to a
> problem that I don't have!

Well, it's a bad answer. You don't need all that crap. The regulators
only serve to limit the current (absolute max & various power levels)
and to boost the voltage (when the cell voltage is below LED forward
bias). The dynamo has a large series inductance which acts as a ballast,
effectively limiting the current. The simple way to get multiple power
levels is to switch LED's in & out.


> The reason that the woman said "you're blinding me" last Saturday
> evening is because she was coming almost directly toward me on a narrow
> path. Normally an oncoming rider or vehicle would not be looking
> straight-on into the center part of the beam. What I normally do on
> bicycle trails is to go to a lower brightness if there is oncoming
> traffic. Like most higher end LED lights, this light is digitally
> regulated, and it has 4 different settings (9, 40, 80, 135 lumens) as
> well as two flashing modes (strobe and S.O.S.). I just didn't see anyone
> else coming because no one had lights. If these riders want to be
> treated courteously by other riders (and most regular night riders do
> have very good lights) then they need to get with the plan and have
> lights themselves. That's why the rental place should offer them.


Well perhaps, but I think blinding the light-less rider isn't improving
the situation. I find unlit riders to be a rather common situation here
in Boston. In any case, I can't see the harm in putting a hood over a
symmetrical beam to cutoff the upward spill. I've had the experience of
being dazzled by oncoming bike lights, it's not pleasant.


> BTW, do any of the dynamo LED lights have brightness that's adjustable
> in any way when you're riding fast enough that you might not need full
> brightness?

I don't get the problem, the faster I go, the more light I want.

[SMS]

Peter Cole wrote:
> SMS wrote:
>
>> What I could do, is to build a switcher that could drive the LED
>> flashlight lamp from the dynamo. It's require a bridge rectifier, some
>> capacitors, and a buck boost switching regulator. I calculated the
>> losses of the conversion at about 30% minimum, using best case, ideal
>> components (it's probably closer to 40%), but it's an answer to a
>> problem that I don't have!
>
> Well, it's a bad answer. You don't need all that crap. The regulators
> only serve to limit the current (absolute max & various power levels)
> and to boost the voltage (when the cell voltage is below LED forward
> bias). The dynamo has a large series inductance which acts as a ballast,
> effectively limiting the current. The simple way to get multiple power
> levels is to switch LED's in & out.

Then LED headlights for dynamos should do that automatically rather than
use switching regulators.

Look at how you select a current limiting resistor for a simple LED
circuit. You look at the voltage that will be powering the LED, and you
calculate the current through the LED, and you look at the forward
voltage of the LED. Just because the dynamo puts out a relatively
constant current doesn't mean that you can put as much voltage as you
want across the LED.

You can play with an LED calculator at "http://led.linear1.org/1led.wiz".

I have a little hand crank dynamo that I soldered an LED to the outputs.
The faster you crank it the higher the voltage, and the brighter the
LED, until the LED burns out! Very similar to the cheaper LED dynamo
lights that warn against going over 7.5 volts. I understand why they
don't want to add the regulation circuitry; besides adding cost, it
reduces efficiency. But they could at least add some sort of
over-voltage protection as is done for incandescent dynamo lamps.

[SMS]

Peter Cole wrote:

> No, but I don't think anybody is designing new lights around MR
> (multifaceted reflector) anymore. The reflector on those is designed to
> diffuse the beam to avoid hot spots. LED's have much more compact
> emitters, and even those that use a textured reflector diffuse the beam
> much less.

MR lamps are still widely used in commercial battery powered lighting
systems. Note that while MR does stand for multifaceted reflector, there
are lamps that have smooth reflectors as well. It all depends on the
beam that you want to project.

One advantage of MR lamps is that you can have higher wattages because
of the way they dissipate the heat through the reflector. With LEDs (as
with many semiconductors) the thermodynamic challenges are very great as
the power increases. Just look at the white papers on dealing with high
power LED heat dissipation!

> I really think the only thing necessary to adapt a symmetrical beam like
> those from a flashlight or MTB light is to just put a small hood on it.
> Fresnel type lenses can shape the beam, but they tend to introduce
> artifacts, too.

Yeah, you could do this, but it really isn't necessary. Very little of
the light is "wasted" as it is.

[Kevin McMurtrie[_2_]]

There's a reason that most bike lights have crappy regulation. LEDs
have a somewhat logarithmic light output for input power plus a human
eye has a logarithmic sensitivity. This means that the low power
setting may be 5mA and the high power setting 1000mA. That 1:200 ratio
can't be done accurately and efficiently with cheap parts.

I built a combination hiking & biking lamp using 21 Luxeon Rebel LEDs.
I managed to perform a fully variable output by attaching the low end of
the pot to voltage feedback and the high end to current feedback. It
works very well but it requires binned LEDs and calibration to that bin.
That's probably not cost-effective for a consumer light. I also haven't
checked efficiency at low power yet. With such a huge output range,
regulator has to go between continuous and discontinuous modes at the
right time to be efficient.

--
Google is a pro-spamming service. I will not see your reply if you use Google.

[Peter Cole[_2_]]

SMS wrote:
> Peter Cole wrote:
>> SMS wrote:
>>
>>> What I could do, is to build a switcher that could drive the LED
>>> flashlight lamp from the dynamo. It's require a bridge rectifier,
>>> some capacitors, and a buck boost switching regulator. I calculated
>>> the losses of the conversion at about 30% minimum, using best case,
>>> ideal components (it's probably closer to 40%), but it's an answer to
>>> a problem that I don't have!
>>
>> Well, it's a bad answer. You don't need all that crap. The regulators
>> only serve to limit the current (absolute max & various power levels)
>> and to boost the voltage (when the cell voltage is below LED forward
>> bias). The dynamo has a large series inductance which acts as a
>> ballast, effectively limiting the current. The simple way to get
>> multiple power levels is to switch LED's in & out.
>
> Then LED headlights for dynamos should do that automatically rather than
> use switching regulators.
>
> Look at how you select a current limiting resistor for a simple LED
> circuit. You look at the voltage that will be powering the LED, and you
> calculate the current through the LED, and you look at the forward
> voltage of the LED. Just because the dynamo puts out a relatively
> constant current doesn't mean that you can put as much voltage as you
> want across the LED.
>
> You can play with an LED calculator at "http://led.linear1.org/1led.wiz".
>
> I have a little hand crank dynamo that I soldered an LED to the outputs.
> The faster you crank it the higher the voltage, and the brighter the
> LED, until the LED burns out! Very similar to the cheaper LED dynamo
> lights that warn against going over 7.5 volts. I understand why they
> don't want to add the regulation circuitry; besides adding cost, it
> reduces efficiency. But they could at least add some sort of
> over-voltage protection as is done for incandescent dynamo lamps.

Diodes are limited in forward bias by current, in reverse bias by
voltage. You regulate the current. The maximum current a dynamo can
produce is its short circuit current, that's determined by its
inductance and resistance. If you blew a diode it's because you exceeded
its maximum current rating, voltage isn't meaningful.

[Peter Cole[_2_]]

SMS wrote:
> Peter Cole wrote:
>
>> No, but I don't think anybody is designing new lights around MR
>> (multifaceted reflector) anymore. The reflector on those is designed
>> to diffuse the beam to avoid hot spots. LED's have much more compact
>> emitters, and even those that use a textured reflector diffuse the
>> beam much less.
>
> MR lamps are still widely used in commercial battery powered lighting
> systems. Note that while MR does stand for multifaceted reflector, there
> are lamps that have smooth reflectors as well. It all depends on the
> beam that you want to project.

Out of 46 lights at Nashbar, only 1 seemed to be MR type, and I don't
think that's a new model.

> One advantage of MR lamps is that you can have higher wattages because
> of the way they dissipate the heat through the reflector. With LEDs (as
> with many semiconductors) the thermodynamic challenges are very great as
> the power increases. Just look at the white papers on dealing with high
> power LED heat dissipation!

Sub 10W power dissipation is trivial. All you need is a passive
heatsink. Cheap power transistors and diodes have been around for
decades, devices that handle much higher power levels.

>> I really think the only thing necessary to adapt a symmetrical beam
>> like those from a flashlight or MTB light is to just put a small hood
>> on it. Fresnel type lenses can shape the beam, but they tend to
>> introduce artifacts, too.
>
> Yeah, you could do this, but it really isn't necessary. Very little of
> the light is "wasted" as it is.

The issue wasn't wasting light, but rather preventing glare to oncoming
traffic.

[Peter Cole[_2_]]

Kevin McMurtrie wrote:
> There's a reason that most bike lights have crappy regulation. LEDs
> have a somewhat logarithmic light output for input power

Not any that I've seen.

> plus a human
> eye has a logarithmic sensitivity. This means that the low power
> setting may be 5mA and the high power setting 1000mA. That 1:200 ratio
> can't be done accurately and efficiently with cheap parts.

I can't imagine that wide a range being useful for a bike light, but I
don't see the problem in doing that with a simple (and cheap) PWM
(chopper) module.


> I built a combination hiking & biking lamp using 21 Luxeon Rebel LEDs.
> I managed to perform a fully variable output by attaching the low end of
> the pot to voltage feedback and the high end to current feedback. It
> works very well but it requires binned LEDs and calibration to that bin.
> That's probably not cost-effective for a consumer light. I also haven't
> checked efficiency at low power yet. With such a huge output range,
> regulator has to go between continuous and discontinuous modes at the
> right time to be efficient.

The problem with running diodes in parallel is that you can't control
the amount of current each diode passes (current sharing). It gets worse
because those diodes that pass more heat up more, drop forward voltage
and you get thermal runaway. You really need 1 regulator per diode or
series connected string of diodes.

[Kevin McMurtrie[_2_]]

In article >,
Peter Cole > wrote:

> Kevin McMurtrie wrote:
> > There's a reason that most bike lights have crappy regulation. LEDs
> > have a somewhat logarithmic light output for input power
>
> Not any that I've seen.
>
> > plus a human
> > eye has a logarithmic sensitivity. This means that the low power
> > setting may be 5mA and the high power setting 1000mA. That 1:200 ratio
> > can't be done accurately and efficiently with cheap parts.
>
> I can't imagine that wide a range being useful for a bike light, but I
> don't see the problem in doing that with a simple (and cheap) PWM
> (chopper) module.

1:200 current ratio has a much, much smaller visual ratio. That's the
problem.

>
> > I built a combination hiking & biking lamp using 21 Luxeon Rebel LEDs.
> > I managed to perform a fully variable output by attaching the low end of
> > the pot to voltage feedback and the high end to current feedback. It
> > works very well but it requires binned LEDs and calibration to that bin.
> > That's probably not cost-effective for a consumer light. I also haven't
> > checked efficiency at low power yet. With such a huge output range,
> > regulator has to go between continuous and discontinuous modes at the
> > right time to be efficient.
>
> The problem with running diodes in parallel is that you can't control
> the amount of current each diode passes (current sharing). It gets worse
> because those diodes that pass more heat up more, drop forward voltage
> and you get thermal runaway. You really need 1 regulator per diode or
> series connected string of diodes.

Putting LEDs in series sums their internal resistances while averaging
their forward voltages. Matched LEDs balance well with only 2 or 3 in
series. Random LEDs (of same type) balance well with 4+ in series.

Mine is 7 groups of 3 in series of matched LEDs. They're soldered to a
0.001" thick 1 Oz foil PCB bonded to a 0.010" copper sheet with a
pyrolytic graphite heat spreader behind it. It will do 3780 lumens for
about 2 minutes (50W) before the whole thing is too hot to hold. The
crazy-high momentary output is for hiking when I need to find a distant
landmark. Normal bicycling needs about 2W input and walking about 1W
input.

I got some photos:

Copper form and heat spreader:
<http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%205.0/Copper.
jpg>

Pyrolytic graphite heat spreader:
<http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%205.0/pyrolyt
icgraphite.jpg>

LED board:
<http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%205.0/LED%20b
oard.jpg>

Regulator board:
<http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%205.0/regulat
or.jpg>

Early carbon fiber stage:
<http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%205.0/carbonf
iber.jpg>

Mounting surface for LED board:
<http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%205.0/mountsu
rface.jpg>


Done:
<http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%205.0/Front.j
pg>
<http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%205.0/Back.jp
g>

50W LED versus 100W incandescent exam light:
<http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%205.0/vs100W.
jpg>

--
Google is a pro-spamming service. I will not see your reply if you use Google.

[SMS]

Peter Cole wrote:

> Diodes are limited in forward bias by current, in reverse bias by
> voltage. You regulate the current. The maximum current a dynamo can
> produce is its short circuit current, that's determined by its
> inductance and resistance. If you blew a diode it's because you exceeded
> its maximum current rating, voltage isn't meaningful.

In an LED circuit you select the current limiting resistor based on the
internal resistance of the LED which is calculated by the forward
voltage and the maximum current. As the voltage increases, you need a
larger resistor to keep the current below the maximum. You have the same
issue with a dynamo, unless you want to keep adding LEDs in parallel as
the voltage goes up to keep the current through each one below the
maximum. The voltage and current are directly related to each other.
Unless you have a CVCC dynamo, you need to regulate the voltage somewhere.

[Peter Cole[_2_]]

SMS wrote:
> Peter Cole wrote:
>
>> Diodes are limited in forward bias by current, in reverse bias by
>> voltage. You regulate the current. The maximum current a dynamo can
>> produce is its short circuit current, that's determined by its
>> inductance and resistance. If you blew a diode it's because you
>> exceeded its maximum current rating, voltage isn't meaningful.
>
> In an LED circuit you select the current limiting resistor based on the
> internal resistance of the LED which is calculated by the forward
> voltage and the maximum current. As the voltage increases, you need a
> larger resistor to keep the current below the maximum. You have the same
> issue with a dynamo, unless you want to keep adding LEDs in parallel as
> the voltage goes up to keep the current through each one below the
> maximum. The voltage and current are directly related to each other.
> Unless you have a CVCC dynamo, you need to regulate the voltage somewhere.

Consider the equivalent circuit of a dynamo, then all should become clear.

[Jym Dyer]

> I owned an SUV before the term SUV was even coined (an old
> Toyota Land Cruiser). I had to sell it once everyone had an
> SUV, or I would be accused of being a conformist.

=v= Are we supposed to be impressed by this? That you bought
a Land Bruiser in a hipsterly before-it-was-cool way? That
you were a pioneer in the thoughtless consumption and waste
and pollution that comes with inflicting a Land Crusher on the
planet, not to mention on the streets where bikers need room?

=v= Ah well, I was *agitating* against these corporate tool-
mobiles back then. We had these lovely anti-4x4 stickers that
were so presciently cutting-edge that they foresaw the issue
of their drivers' tiny penises. Way more hipper-than-thou.
<_Jym_>

[Frank Krygowski[_2_]]

On Nov 27, 10:44*am, SMS > wrote:
>
> The symmetrical beam is not a problem. Look at the beam pattern when the
> light is properly aimed. The center spot illuminates the road directly
> ahead, while the flood provides a "being seen" light that is not blinding..
>
> "http://i34.tinypic.com/2enls0x.jpg"

First, if symmetrical beams were not a problem, then every auto
manufacturer, every motorcycle manufacturer, every scooter
manufacturer and moped manufacturer and tractor manufacturer in the
world would save money by using them. Given that NONE of those
manufacturers fit symmetrical beams for road use, it's very likely
you're not understanding something.

Now, as others have explained in the past: The problem with you
pointing that bright spot downward to avoid blinding others is this:
you get much more intensity where it's not needed, and much less where
it would be helpful. This _does_ have a downside, in that it harms
your night vision. You're less able to see things not contained in
that bright spot. Furthermore, you've got to draw more watts to make
up for your crude beam shape. That decreases battery run time, and
increases battery expense and weight.

Good road optics would give a much more uniform illumination of the
road. It would give a good cutoff, which would reduce blinding of
other road users. Top notch optics would make the beam brighter just
below the cutoff, to see further down the road, and less bright lower
than that, since the lower part of the beam doesn't shine as far
away.

If you have plenty of lumens to pump out there, you can widen the beam
to cover a full lane or more with uniform brightness. Optimum beam
shape to cover the lane is rectangular or trapezoidal.

I have a battery powered headlight that gives a beam identical to what
you've shown in that photo. It's simply not as good as the beam from
a good generator headlamp. In fact, if I wanted to get brighter
halogen light using a battery source instead of a generator, I'd still
use the optics from a good generator lamp, and just substitute a
higher wattage halogen bulb.

- Frank Krygowski

[Frank Krygowski[_2_]]

On Nov 27, 11:36*am, SMS > wrote:
> Peter Cole wrote:
> > SMS wrote:
>
> >> What I could do, is to build a switcher that could drive the LED
> >> flashlight lamp from the dynamo. It's require a bridge rectifier, some
> >> capacitors, and a buck boost switching regulator. I calculated the
> >> losses of the conversion at about 30% minimum, using best case, ideal
> >> components (it's probably closer to 40%), but it's an answer to a
> >> problem that I don't have!
>
> > Well, it's a bad answer. You don't need all that crap. The regulators
> > only serve to limit the current (absolute max & various power levels)
> > and to boost the voltage (when the cell voltage is below LED forward
> > bias). The dynamo has a large series inductance which acts as a ballast,
> > effectively limiting the current. The simple way to get multiple power
> > levels is to switch LED's in & out.
>
> Then LED headlights for dynamos should do that automatically rather than
> use switching regulators.
>
> Look at how you select a current limiting resistor for a simple LED
> circuit. You look at the voltage that will be powering the LED, and you
> calculate the current through the LED, and you look at the forward
> voltage of the LED. Just because the dynamo puts out a relatively
> constant current doesn't mean that you can put as much voltage as you
> want across the LED.
>
> You can play with an LED calculator at "http://led.linear1.org/1led.wiz".

Your LED calculator site is using a battery, which is essentially a
constant voltage source.

Do you not understand that if you use a bike generator, which is
naturally a constant current, 1/2 amp source, the current though an
LED will be 1/2 amp?

Do you not understand that if a bike generator is pumping its current
into a circuit with negligible resistance, the output voltage of the
generator will be negligible? The output voltage rises only to the
amount needed to provide 1/2 amp.

> I have a little hand crank dynamo that I soldered an LED to the outputs.
> * *The faster you crank it the higher the voltage, and the brighter the
> LED, until the LED burns out!

We don't know what your little hand crank dynamo is; but there's a
very strong chance it differs from a bike generator.

- Frank Krygowski

[Peter Cole[_2_]]

Kevin McMurtrie wrote:

> Mine is 7 groups of 3 in series of matched LEDs. They're soldered to a
> 0.001" thick 1 Oz foil PCB bonded to a 0.010" copper sheet with a
> pyrolytic graphite heat spreader behind it. It will do 3780 lumens for
> about 2 minutes (50W) before the whole thing is too hot to hold. The
> crazy-high momentary output is for hiking when I need to find a distant
> landmark. Normal bicycling needs about 2W input and walking about 1W
> input.

Wouldn't it have been a lot simpler (not to mention efficient) to just
switch to 1 or 2 LED operation for walking and biking?

50W of power LED's seems crazy powerful -- not that there's anything
wrong with building crazy powerful stuff. If I was going that big, I'd
be interested in trying some of the fancy heat pipe heatsinks like this
one: http://www.newegg.com/Product/Product.aspx?Item=N82E16835233021

That could probably run 50W continuously without getting even very warm.

Of course these days you could get all those lumens with just 4 SSC p7's.

For a quick and dirty LED bike light I've been intrigued by using an off
the shelf 3W MR16 unit like this one:

http://www.dealextreme.com/details.dx/sku.13842

The simplicity comes from the fact that the heatsink reflector and
regulator are all integrated. Some of these have internal bridge
rectifiers, so could run right off a dynamo. The problem is finding one
in a narrow spot.

[Frank Krygowski[_2_]]

On Nov 28, 12:23*am, Peter Cole > wrote:
> SMS wrote:
> >
> > Yeah, you could do this, but it really isn't necessary. Very little of
> > the light is "wasted" as it is.
>
> The issue wasn't wasting light, but rather preventing glare to oncoming
> traffic.

Personally, I think the issue is both.

Light that's directed upward does cause glare in oncoming vehicle
operators' eyes. But it's also wasted light. You want to see the
road well. If your headlight sends lumens upward, those lumens are
not showing you the road.

I suppose that, if one has far more lumen output than one needs, the
upward portion of a crude symmetrical beam could even be absorbed, say
by black cloth. But in bicycling, efficiency is much more valuable
than in most endeavors. It doesn't make sense to me to consume power,
then throw it away. Rather, apply careful design to give good
efficiency, as is done in all other bicycling matters.

- Frank Krygowski

[Peter Cole[_2_]]

Frank Krygowski wrote:
> On Nov 28, 12:23 am, Peter Cole > wrote:
>> SMS wrote:
>>> Yeah, you could do this, but it really isn't necessary. Very little of
>>> the light is "wasted" as it is.
>> The issue wasn't wasting light, but rather preventing glare to oncoming
>> traffic.
>
> Personally, I think the issue is both.
>
> Light that's directed upward does cause glare in oncoming vehicle
> operators' eyes. But it's also wasted light. You want to see the
> road well. If your headlight sends lumens upward, those lumens are
> not showing you the road.
>
> I suppose that, if one has far more lumen output than one needs, the
> upward portion of a crude symmetrical beam could even be absorbed, say
> by black cloth. But in bicycling, efficiency is much more valuable
> than in most endeavors. It doesn't make sense to me to consume power,
> then throw it away. Rather, apply careful design to give good
> efficiency, as is done in all other bicycling matters.
>
> - Frank Krygowski

Sure, but plain old incandescent dynamo lights are in the range of 30
lumens while today's equivalent LED's are approaching 10x that. You
don't need to be so frugal. The downside of that frugality is the
artifacts that lens type beam shapers add. Your criticism seems to be
focused <ahem> on those using too wide beams for road riding. 30 degree
beams may be OK, or even preferable, for off-road but 10 degree beams
are much better for the road. I find beams with a lot of artifacts
tiring to ride with because you're trying to spot debris and holes via
the shadows and artifacts/uneven beams make those harder to spot.

The original context of this thread was a complaint about a complaint.
The OP felt that unlit cyclists didn't give him enough time to dim his
headlight to prevent dazzling them. I don't think upward spill on a
tightly focused beam (such as the Fenix he described) represents much in
the way of lost efficiency, so just shading it with a hood would
eliminate the dazzle effect. Some side spill is advantageous to provide
"be seen" light and to prevent tunnel vision. Auto headlights have large
horiz. to vert. beam angles, but they also have power to burn, I'm not
sure that is at all necessary for a bike light.

[Kevin McMurtrie[_2_]]

In article >,
Peter Cole > wrote:

> Kevin McMurtrie wrote:
>
> > Mine is 7 groups of 3 in series of matched LEDs. They're soldered to a
> > 0.001" thick 1 Oz foil PCB bonded to a 0.010" copper sheet with a
> > pyrolytic graphite heat spreader behind it. It will do 3780 lumens for
> > about 2 minutes (50W) before the whole thing is too hot to hold. The
> > crazy-high momentary output is for hiking when I need to find a distant
> > landmark. Normal bicycling needs about 2W input and walking about 1W
> > input.
>
> Wouldn't it have been a lot simpler (not to mention efficient) to just
> switch to 1 or 2 LED operation for walking and biking?
>
> 50W of power LED's seems crazy powerful -- not that there's anything
> wrong with building crazy powerful stuff. If I was going that big, I'd
> be interested in trying some of the fancy heat pipe heatsinks like this
> one: http://www.newegg.com/Product/Product.aspx?Item=N82E16835233021
>
> That could probably run 50W continuously without getting even very warm.
>
> Of course these days you could get all those lumens with just 4 SSC p7's.
>
> For a quick and dirty LED bike light I've been intrigued by using an off
> the shelf 3W MR16 unit like this one:
>
> http://www.dealextreme.com/details.dx/sku.13842
>
> The simplicity comes from the fact that the heatsink reflector and
> regulator are all integrated. Some of these have internal bridge
> rectifiers, so could run right off a dynamo. The problem is finding one
> in a narrow spot.

Most modern LEDs have logarithmic output for input power. If you need
lots of LEDs for momentary power, it's much more efficient to dim all of
them than to switch some off or use pulsing. The only downside to
running them at very low power is that there may be a color shift.
That's not a problem in the dark.

It's OK that I can't run at full power continuously. That's just for
finding landmarks out in the middle of nowhere. Weight, size, power
efficiency below 5W, and momentary brightness were my concerns.

My previous hiking light was 2 CCFLs and a 50W halogen light in a small
acrylic tube. The CCFLs worked great but the halogen lamp had insane
inrush current. My bike had 2 CCFLs and a carbon fiber+mylar parabolic
reflector that was perfect for biking but too fragile and dim for
hiking. LEDs were just the trick to put all the features into one tiny
lamp.


Saw this today:
<http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/11/28/BAD014DMJT.D
TL&feed=rss.bayarea>
"Two thousand free bike lights will be distributed around San Francisco
on Tuesday to put the spotlight on bicycle safety."

Just blinking red lights, but it's good to see bicycles more accepted as
common around-town transportation.

--
Google is a pro-spamming service. I will not see your reply if you use Google.

[Tom Sherman[_3_]]

Jym Dyer wrote:
>> I owned an SUV before the term SUV was even coined (an old
>> Toyota Land Cruiser). I had to sell it once everyone had an
>> SUV, or I would be accused of being a conformist.
>
> =v= Are we supposed to be impressed by this? That you bought
> a Land Bruiser in a hipsterly before-it-was-cool way? That
> you were a pioneer in the thoughtless consumption and waste
> and pollution that comes with inflicting a Land Crusher on the
> planet, not to mention on the streets where bikers need room?
>
> =v= Ah well, I was *agitating* against these corporate tool-
> mobiles back then. We had these lovely anti-4x4 stickers that
> were so presciently cutting-edge that they foresaw the issue
> of their drivers' tiny penises. Way more hipper-than-thou.
>
When I drove one on the old (early 1980's) Land Cruiser station wagons,
it was used as a work truck to carry equipment (worth more than the
truck) in a weather protected cargo area to locations that an automobile
would not be able to get to. Not a damn thing to do with being cool, hip
or any other social status.

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Tom Sherman[_3_]]

Dane Buson wrote:
> Tom Sherman > wrote:
>> Dane Buson wrote:
>>> Tom Sherman > wrote:
>
>>>> Recumbent bicycles are not that expensive!
>>> Now Tom, I thought we agreed we weren't going to talk about those in
>>> polite company?
>>>
>>> /me looks around
>>>
>>> Errrr, never mind, carry on.
>>>
>> Indeed! ;)
>>
>>> Any recommendations for a tadpole trike? I'm getting tired of banging
>>> my hips during icy winter days.
>> USian made, and reasonably priced: <http://www.catrike.com/>.
>
> Possible, but since I'd only rarely be riding it, still too much cash.
> Admittedly I knew that before I even asked the question. I guess it's
> time to pick up some Atomic Zombie books.
>
Economy of scale, not excess manufacturer profit is the culprit here.

>> High performance, good handling but still corrosion resistant:
>> <http://www.windcheetah.co.uk/>.
>
> Hmm, did I mention I want a trike, not to establish an annuity for their
> grandchildren?
>
With the cost of sourcing all the special parts on the Windcheetah
"Speedy", I can state with great confidence that no one is getting rich.
Direct your accusations of greed to the financial sector instead.

>> Rear suspension is nice, since it is hard to avoid potholes with all
>> three wheel tracks, and this one is also corrosion resistant:
>> <http://www.optima-cycles.nl/main/en/modellen/5.html?Itemid=27>.
>>
>> Laugh at the cold rain: <http://leitra.dk/news.php>.
>
> Which should be nicely balanced by the people laughing at you. I'm fine
> with a regular trike, but the enclosed ones turn the dork factor up to
> 11. Not to mention I cross multiple bridges with *high* winds at times.
>
A Unix Bigot is concerned about the Dork Factor being too high???

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[SMS]

Tom Sherman wrote:

> When I drove one on the old (early 1980's) Land Cruiser station wagons,
> it was used as a work truck to carry equipment (worth more than the
> truck) in a weather protected cargo area to locations that an automobile
> would not be able to get to. Not a damn thing to do with being cool, hip
> or any other social status.

Yes, I had the same vintage. I bought it because it was the lowest cost
vehicle that I could take five people and gear, on backpacking and X-C
ski trips where a 4WD vehicle was required to go on roads where regular
passenger cars could not travel. Later I expanded the passenger capacity
to five adults/3 children with a third seat, which enabled driving one
vehicle instead of two on many excursions.

It had nothing to do with being cool or hip. Not sure what got aomeone's
panties in a bunch about all this! The problem with SUVs is that they've
become MTVs (Mall Terrain Vehicles) driven daily as commute vehicles,
rather than being used primarily when more cargo or passenger carrying
space is needed, or when the 4WD capability is necessary.

While walking or cycling in San Francisco, the vehicles I notice
behaving the poorest in terms of running red lights, or driving
erratically are Muni buses, taxis, and bicycles. The SFPD should crack
down on these, but they won't.

[Tom Kunich]

"SMS" > wrote in message
...
>
> Yes, I had the same vintage. I bought it because it was the lowest cost
> vehicle that I could take five people and gear, on backpacking and X-C ski
> trips where a 4WD vehicle was required to go on roads where regular
> passenger cars could not travel. Later I expanded the passenger capacity
> to five adults/3 children with a third seat, which enabled driving one
> vehicle instead of two on many excursions.

Strange, I used to ride motorcycles off-road and the guys I went with had a
Dodge Charger with the hemi pulling a motorcycle trailer. And we went into
the furthest backwoods with that and all our camping equipment for days.
Seems as how the limited slip differential worked just as well as everyone
else's Jeep. And since the lowest point on a car is the differential anyway
we got through where anyone else could.

[Tom Sherman[_3_]]

Tom Kunich wrote:
> "SMS" > wrote in message
> ...
>>
>> Yes, I had the same vintage. I bought it because it was the lowest
>> cost vehicle that I could take five people and gear, on backpacking
>> and X-C ski trips where a 4WD vehicle was required to go on roads
>> where regular passenger cars could not travel. Later I expanded the
>> passenger capacity to five adults/3 children with a third seat, which
>> enabled driving one vehicle instead of two on many excursions.
>
> Strange, I used to ride motorcycles off-road and the guys I went with
> had a Dodge Charger with the hemi pulling a motorcycle trailer. And we
> went into the furthest backwoods with that and all our camping equipment
> for days. Seems as how the limited slip differential worked just as well
> as everyone else's Jeep. And since the lowest point on a car is the
> differential anyway we got through where anyone else could.

The above only worked because Kunich is the Master of All Trades, with
far more ability than the average person. ;)

--
Tom Sherman - 42.435731,-83.985007
If you are not a part of the solution, you are a part of the precipitate.

[Peter Cole[_2_]]

Kevin McMurtrie wrote:

> Most modern LEDs have logarithmic output for input power.

LEDs typically have a roughly linear relationship between light output
and input current. Since the forward voltage is relatively constant, the
IxV product (power) is roughly linear as well. The combination of
increase in forward voltage and drop in efficiency at maximum current
and increased junction temperatures makes for a departure from
linearity, but hardly logarithmic.

> If you need
> lots of LEDs for momentary power, it's much more efficient to dim all of
> them than to switch some off or use pulsing.

How are you dimming all of them if not pulsing (PWM)? LEDs are a bit
more efficient at less than max power, but regulators are very much the
opposite.

> The only downside to
> running them at very low power is that there may be a color shift.

There isn't, at least not much of one for white (phosphor) LEDs. 0->100%
= 455->458nm, from one study.


> It's OK that I can't run at full power continuously. That's just for
> finding landmarks out in the middle of nowhere. Weight, size, power
> efficiency below 5W, and momentary brightness were my concerns.
>
> My previous hiking light was 2 CCFLs and a 50W halogen light in a small
> acrylic tube. The CCFLs worked great but the halogen lamp had insane
> inrush current.

All halogens have a large inrush current, that didn't stop them from
being the dominant bike light until LEDs came along.

> My bike had 2 CCFLs and a carbon fiber+mylar parabolic
> reflector that was perfect for biking but too fragile and dim for
> hiking.

How big was that reflector? The problem for florescent lights has always
been focusing the beam. The larger the source element, the larger the
reflector must be.

[Kevin McMurtrie[_2_]]

In article >,
Peter Cole > wrote:

> Kevin McMurtrie wrote:
>
> > Most modern LEDs have logarithmic output for input power.
>
> LEDs typically have a roughly linear relationship between light output
> and input current. Since the forward voltage is relatively constant, the
> IxV product (power) is roughly linear as well. The combination of
> increase in forward voltage and drop in efficiency at maximum current
> and increased junction temperatures makes for a departure from
> linearity, but hardly logarithmic.
>
> > If you need
> > lots of LEDs for momentary power, it's much more efficient to dim all of
> > them than to switch some off or use pulsing.
>
> How are you dimming all of them if not pulsing (PWM)? LEDs are a bit
> more efficient at less than max power, but regulators are very much the
> opposite.

I'm dimming the LEDs through a mix of voltage and current feedback
regulation. The low end of the adjustment pot is voltage feedback and
the high end of the pot is current feedback. It sounds crazy but it
produces a visually linear adjustment. I may put the schematic online
some time.

This is pulled from eyeballing the white Rebel data charts, with 350mA
being 100%:

100mA : 2.85V : 0.285W : 25% power, 35% light
175mA : 3.00V : 0.525W : 47% power, 60% light
350mA : 3.19V : 1.12W : 100% power, 100% light
700mA : 3.35V : 2.35W : 209% power, 160% light
1000mA: 3.50V : 3.50W : 313% power, 210% light

Simple buck regulators loose much of their power through the diode that
routes power out of the inductor during the off cycle. It's a loss of
0.4V * current * (100% - dutycycle). Nearing saturation of the inductor
is a large loss too. I've tried to keep the current low and the duty
cycle high by setting up the LEDs to run at 8 to 10 V from 12-16V.

> > The only downside to
> > running them at very low power is that there may be a color shift.
>
> There isn't, at least not much of one for white (phosphor) LEDs. 0->100%
> = 455->458nm, from one study.

Not always true. Manufacturers state that they don't test color quality
at low power. If you look at a large batch of white LEDs at low power,
a number of them will be green or purple.

>
> > It's OK that I can't run at full power continuously. That's just for
> > finding landmarks out in the middle of nowhere. Weight, size, power
> > efficiency below 5W, and momentary brightness were my concerns.
> >
> > My previous hiking light was 2 CCFLs and a 50W halogen light in a small
> > acrylic tube. The CCFLs worked great but the halogen lamp had insane
> > inrush current.
>
> All halogens have a large inrush current, that didn't stop them from
> being the dominant bike light until LEDs came along.

Very true. It's just a limiting factor in what kind of battery can be
used. I'd rather use small packs of high capacity NiMH or LiIon, but
those can be damaged by the current needed to start up a 50W halogen.


> > My bike had 2 CCFLs and a carbon fiber+mylar parabolic
> > reflector that was perfect for biking but too fragile and dim for
> > hiking.
>
> How big was that reflector? The problem for florescent lights has always
> been focusing the beam. The larger the source element, the larger the
> reflector must be.

It was a linear parabolic reflector about 11 inches wide and about 2.75
inches deep and high. The edges were slightly curled in to improve
center illumination. Most described it as brilliant moon light.
Somebody stole it and the Giant bike it was on at the time. Here's an
old photo of it:

http://www.pixelmemory.us/Photos/Nerd/Alien%20Bike%20Light%203.0/

--
Google is a pro-spamming service. I will not see your reply if you use Google.

[SMS]

Kevin McMurtrie wrote:

> I'm dimming the LEDs through a mix of voltage and current feedback
> regulation. The low end of the adjustment pot is voltage feedback and
> the high end of the pot is current feedback. It sounds crazy but it
> produces a visually linear adjustment. I may put the schematic online
> some time.

Not crazy at all. Look at how the high end LED flashlights adjust
brightness. They use a buck-boost voltage regulator. They have a similar
issue as dynamos as they typically will use the same LED head on
different battery tubes, which can be interchanged. You can run the same
head on a variety of voltages, but the output doesn't vary.

[Peter Cole[_2_]]

SMS wrote:
> Kevin McMurtrie wrote:
>
>> I'm dimming the LEDs through a mix of voltage and current feedback
>> regulation. The low end of the adjustment pot is voltage feedback and
>> the high end of the pot is current feedback. It sounds crazy but it
>> produces a visually linear adjustment. I may put the schematic online
>> some time.
>
> Not crazy at all. Look at how the high end LED flashlights adjust
> brightness. They use a buck-boost voltage regulator. They have a similar
> issue as dynamos as they typically will use the same LED head on
> different battery tubes, which can be interchanged. You can run the same
> head on a variety of voltages, but the output doesn't vary.

Boosters for LEDs (e.g. to run 3.5V LED off 1.25V battery) typically
switch a current through an inductor. When the current is cut off, the
voltage spikes. The open circuit voltage typically goes much higher than
the LED forward bias voltage, the LED clamps it. Dynamos have a similar
series inductance and a similar high open circuit voltage. That doesn't
suggest that a voltage booster is needed for a dynamo (or reducer for
that matter). In either case the current is set (primarily) by the
inductance and the frequency. The voltage is set by the LED itself. In
short, the LED booster circuit works much like a dynamo. Adding
circuitry would be redundant. The only circuitry that might be added
would be a power limiter, limiting the on cycle (like a lamp dimmer),
but given the modest power of a dynamo and the cheap high power LEDs,
that wouldn't seem like a valuable addition.

[Dane Buson]

Tom Sherman > wrote:
> Dane Buson wrote:
>> Tom Sherman > wrote:
>>> Dane Buson wrote:
>>>> Tom Sherman > wrote:
>>
>>>>> Recumbent bicycles are not that expensive!
>>>> Now Tom, I thought we agreed we weren't going to talk about those in
>>>> polite company?
>>>>
>>>> /me looks around
>>>>
>>>> Errrr, never mind, carry on.
>>>>
>>> Indeed! ;)
>>>
>>>> Any recommendations for a tadpole trike? I'm getting tired of banging
>>>> my hips during icy winter days.
>>> USian made, and reasonably priced: <http://www.catrike.com/>.
>>
>> Possible, but since I'd only rarely be riding it, still too much cash.
>> Admittedly I knew that before I even asked the question. I guess it's
>> time to pick up some Atomic Zombie books.
>>
> Economy of scale, not excess manufacturer profit is the culprit here.

Oh, I know, and as I mentioned I thought the catrike was pretty
reasonably priced for a recumbent.

>>> High performance, good handling but still corrosion resistant:
>>> <http://www.windcheetah.co.uk/>.
>>
>> Hmm, did I mention I want a trike, not to establish an annuity for their
>> grandchildren?
>>
> With the cost of sourcing all the special parts on the Windcheetah
> "Speedy", I can state with great confidence that no one is getting rich.
> Direct your accusations of greed to the financial sector instead.

Well yes, noone gets into bicycles to get rich. Well, at least noone
sane.

>>> Rear suspension is nice, since it is hard to avoid potholes with all
>>> three wheel tracks, and this one is also corrosion resistant:
>>> <http://www.optima-cycles.nl/main/en/modellen/5.html?Itemid=27>.
>>>
>>> Laugh at the cold rain: <http://leitra.dk/news.php>.
>>
>> Which should be nicely balanced by the people laughing at you. I'm fine
>> with a regular trike, but the enclosed ones turn the dork factor up to
>> 11. Not to mention I cross multiple bridges with *high* winds at times.
>>
> A Unix Bigot is concerned about the Dork Factor being too high???

Touché.

--
Dane Buson -
A computer without a Microsoft Operating system
is like a dog without bricks tied to it's head.

[doofy[_2_]]

Jym Dyer wrote:
>> I owned an SUV before the term SUV was even coined (an old
>> Toyota Land Cruiser). I had to sell it once everyone had an
>> SUV, or I would be accused of being a conformist.
>
> =v= Are we supposed to be impressed by this? That you bought
> a Land Bruiser in a hipsterly before-it-was-cool way? That
> you were a pioneer in the thoughtless consumption and waste
> and pollution that comes with inflicting a Land Crusher on the
> planet, not to mention on the streets where bikers need room?
>
> =v= Ah well, I was *agitating* against these corporate tool-
> mobiles back then. We had these lovely anti-4x4 stickers that
> were so presciently cutting-edge that they foresaw the issue
> of their drivers' tiny penises. Way more hipper-than-thou.
> <_Jym_>
>

I knew Suzuki Samarai's were roll-over risks long before it came out in
the media, or through statistics. I pulled up behind one, estimicated
the ratio of height to width, and said "****, that thing ain't safe."

What do I get for being so damned smart?

[Jym Dyer]

SMS a.k.a. Steven M. Scharf writes:

> It had nothing to do with being cool or hip. Not sure what
> got aomeone's [sic] panties in a bunch about all this!

=v= It had to do with you bragging rights over not being
an SUV-owner-come-lately. No panties-bunching involved;
I've been going commando since before it was cool or hip.

> The problem with SUVs is that they've become MTVs
> (Mall Terrain Vehicles) driven daily as commute vehicles,
> rather than being used primarily when more cargo or
> passenger carrying space is needed, or when the 4WD
> capability is necessary.

=v= The SUV categorization only exists because of a loophole in
Federal emissions standards that was intended for trucks that
have some actual utility. The marketing was originally aimed at
people who wanted to be thought of as outdoorsy -- my favorite
ad was in _Sierra_, quoting John Muir on the topic of getting
away from it all (e.g. into the plush vinyl padded interior of
an SUV) while driving a fuel guzzling behemoth to the trailhead
(which, you know, is *exactly* how Muir go there).

=v= People yearn for an escape from their malled-in existence
and a lot of them were fooled into buying SUVs that were
marketed as such an escape. Bragging about how your pre-SUV was
The Real Deal and how the plebes who later bought came along and
bought SUVs just feeds into this misperception.
<_Jym_>

[doofy[_2_]]

Jym Dyer wrote:

> =v= People yearn for an escape from their malled-in existence
> and a lot of them were fooled into buying SUVs that were
> marketed as such an escape. Bragging about how your pre-SUV was
> The Real Deal and how the plebes who later bought came along and
> bought SUVs just feeds into this misperception.
> <_Jym_>
>

I became "keeping up with our joneses".

[doofy[_2_]]

doofy wrote:
> Jym Dyer wrote:
>
>> =v= People yearn for an escape from their malled-in existence
>> and a lot of them were fooled into buying SUVs that were
>> marketed as such an escape. Bragging about how your pre-SUV was
>> The Real Deal and how the plebes who later bought came along and
>> bought SUVs just feeds into this misperception.
>> <_Jym_>
>>
>
> I became "keeping up with our joneses".

"It became", not "I became". No SUV's for me. No sir. Uh uhn.

[SMS]

doofy wrote:

> I knew Suzuki Samarai's were roll-over risks long before it came out in
> the media, or through statistics. I pulled up behind one, estimicated
> the ratio of height to width, and said "****, that thing ain't safe."
>
> What do I get for being so damned smart?

Not too much, because the Samurai's were actually no worse than some
other top-heavy, narrow SUVs of the era.

[doofy[_2_]]

SMS wrote:
> doofy wrote:
>
>> I knew Suzuki Samarai's were roll-over risks long before it came out
>> in the media, or through statistics. I pulled up behind one,
>> estimicated the ratio of height to width, and said "****, that thing
>> ain't safe."
>>
>> What do I get for being so damned smart?
>
> Not too much, because the Samurai's were actually no worse than some
> other top-heavy, narrow SUVs of the era.

But, but...this was before anyone was saying anything about it.