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Conbtinental has come out with a GP5000S and a GP5000TL



 
 
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  #71  
Old February 21st 19, 06:41 PM posted to rec.bicycles.tech
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Posts: 1,261
Default Conbtinental has come out with a GP5000S and a GP5000TL

On Wednesday, February 20, 2019 at 3:30:27 PM UTC-8, jbeattie wrote:
On Wednesday, February 20, 2019 at 12:44:59 PM UTC-8, Joerg wrote:
On 2019-02-20 10:21, wrote:
On Wednesday, February 20, 2019 at 9:56:55 AM UTC-8, duane wrote:
On 20/02/2019 10:50 a.m., Joerg wrote:
On 2019-02-18 08:39, Duane wrote:
On 18/02/2019 10:16 a.m., Joerg wrote:
On 2019-02-18 05:35, Duane wrote:
On 17/02/2019 10:57 a.m., Joerg wrote:
On 2019-02-11 15:32,
wrote:
On Sunday, February 10, 2019 at 4:54:06 PM UTC-8, Duane
wrote:
wrote:
On Sunday, February 10, 2019 at 3:52:27 PM UTC+1,
Duane wrote:
wrote:
On Saturday, February 9, 2019 at 7:56:22 PM
UTC+1, Joerg wrote:
On 2019-02-09 09:52,

wrote:


I learned pretty soon that paying more than
$20 for a road bike tire is a waste of money.
In fact, they can be worse than expensive
tires. Similar for MTB tires.

That depends on your riding conditions and
requirements. I ride on good roads on my road
bikes and get 4500 km out of a Continental
4000S(2) rear tire and expect the same from
the 5000 so price is not that important.

Lou



I get about the same mileage and very few flats.
I think I’ve had one flat in the last 10,000km
and that was a tube giving out when I hit a
pothole hard. I ride on roads but I can’t say
they’re always good roads.

Maybe Joerg is riding his road bike on single
track carrying 4 gallons of water or
something...


1-1/2 gallons max, on hot summer days. This is required
on some rides unless you carry chlorine tablets, can
stomach that taste _and_ suppress any thoughts about what
you've seen in the river during kayaking further
upstream.


So you're riding a road bike on single track carrying 1-1/2
gallons of water. Maybe you have the wrong bike for that.


No, I use a 29" FS MTB for that. What I am saying is that the
problem with tires is basically the same whether road bike or
MTB. Expensive tires are designed towards light weight and
performance. Then, their sidewalls fail.


My point is that you seem to have different results from
anyone I know with respect to tires. I don't know anyone
doing any serious mileage on a road bike that thinks
cheaper tires are better.


I have met lots of road bike riders who have realized that
expensive tires just aren't worth it unless you plan to
participate in the Amgen Tour, every millisecond counts and a
team car is there at your beck and call.


Saying that the additional cost is not worth the return for
your specific use case is different than saying that cheaper
tires are better than expensive tires.


They _are_ better. To be "better" isn't necessarily something
that has a better cost/performance ratio but somthing that
doesn't go KAPOOF during ride. I didn't have flats in years,
neither on the MTB nor the road bike. Mission accomplished, I'd
say, and it was accomplished by switching to Asian tires.

As I said this is different for competitive riders who get a new
bike from the team car the second a tire is flat. I do not have a
team car, do not belong to that group and never will.


Well we do have one guy that buys chinese knock off tires
online. He's had so many split tires that we are
contemplating a GoFundMe page for him so we don't have to
keep stopping to put boots in his tires...


Very different here. The rolling surface does wear down
within 2000mi which is slighlty lower than the 2500mi I could
milk out of a Gatorskin. However, I get 2000mi out of every
tire while I only got around 1000mi out of the Gatorskins
where the sidewalls blew.


Are you talking about single track now or are you saying your
roads wear tires down more than say Quebec roads? Hard to keep
track. And do the Gatorskin tires just blow sidewalls or are
you running into ruts or something?


Again, my statement goes for _both_ road and offroad. I do not
know Quebec roads but ours in California have a lot of debris and
are often in very poor condition. Pieces of asphalt broken out
and laying on top and such. The result of inept government.


https://www.google.ca/search?q=quebe...CAAQCA#imgrc=_



Here it's partially the government, partially the +/-40 C temperature
swings and partially the mob supplying the asphalt.

We seem to get by without your tire issues for the most part. I'm
getting ~5000km from my Conti 4000s and rarely get flats.

I try to avoid potholes but I have hit one that caused my tube to
split but I haven't cut a sidewall yet. This happens when you ride
in a tight group and the guy in front of you moves to avoid the
hole at the last second without warning. But you say you keep
yards between you and any other riders so it's hard to understand
your issues.

Whatever. Use what works for you.

On trails the tire torture is of more natural causes, decomposed
granite and sharp rocks, some embedded and some rolling. Then
both on roads and trails there are these which go into runnig
surfaces and sometimes side walls:

https://en.wikipedia.org/wiki/Goat%2...idum_seeds.jpg





If you're talking about trail riding then why do you say road bike? I
don't ride my Tarmac on single track unless I can't avoid it which
is never.

A bike shop owner told me that they aren't native but came in
from places like Arizona just a few years ago. Anyhow, we've got
to deal with all that.


All this assumes a tire liner so I can ride tires down to
their "last mile". In goat's head thorn country wheer I live
a liner is the prudent to do anyhow.

Not sure what you mean by a tire liner. ...


This:

https://www.amazon.com/Mr-Tuffy-Bicy.../dp/B078FHD1ZH

Worth every penny.


... It's not like they are optional as far as I know.


They are optional. Some tires (supposedly) have something similar
built in but my experience is that it fails as soon as the thorn
or whatever hits far enough off-center.

In addition I have thick thron-resistant tubes in the MTB and
road bike tires. For the MTB the tire liner is then sleeved by a
reguar good quality tube with the valve stem removed and slit.
That combination seems to be indestructable. Which was my goal.


My experience with cheap tires was absolutely horrible. They flatted
if you look sideways at them and they wore out so rapidly that they
cost more than using more expensive longer wearing tires.

I'm sort of wondering just how far over the edge that Joerg is
willing to take his tires before replacing them.



With the tire liners in there I use them until thread shows, or at least
close. The running surface becomes very flat in the center.


... I very rarely get
more than 2,500 miles on the very longest wearing tires. I believe
that he is approximately my size and yet he gets almost twice that
distance if I understand him correctly.


No, 2500mi max and only with expensive Gatorskins. Not using them
anymore because of their flimsy side walls. Regular tires of the $12
class last me 1500-2000mi. Depends on brand and where I happen to ride.
Mountainous terrain eats rubber on the uphill sections, literally. When
I am following another guy and it's a quiet area I can hear the vvvt ..
vvvt .. vvvt from his rear tire going uphill.


Or we can go with Frank's previous claim that the graphene layer in
my Vittoria tires doesn't protect anything because a layer only 8
molecules thick couldn't possibly protect anything.

http://www.ukm.my/jsm/pdf_files/SM-P...in%20Chong.pdf

This was a test in medical gloves that have to have several times
the stretch of tires and yet even the very small pieces of graphene
yielded an 11% increase in puncture resistance.

The Vittoria tires have overlapping sheets of the material making it
very puncture resistant. Now these most certainly aren't in the realm
of Joerg's "cheap tires" but they are made in Thailand.


Including shipping I paid $12/ea for the Vittoria Zafiros. That
qualifies as low cost in my book. Jay wrote they don't last but I get
well north of 1500mi out of them and I am not babying my road bike. It
rolls over some nasty stuff. So if there was another sale and I needed
to restock on tires I'd buy those again.


I don't know how long they last, but my Zaffiros have been flat-prone, although not recently. I had a period of three or four flats a while back, but they've been flat-less lately.

I have them in 32mm and run them as my fall-leaves-rain tire because they have a little tread pattern and aren't a pure slick. I have no idea how many miles I have on them because I have zero instrumentation on my commuter -- or any bike. Responding to this posts reminds me that I should look at my rear tire and see if it is worn out.

Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire. They also have just so-so wet grip which is sub-so-so at max inflation pressure. With all that said, they're not a bad tire for the price, and so far, more durable than a Pasela which, IMO, is a very similar tread design.

I'm not going to spend a ton of money on a commuter tire. Riding a commuter with sluggish tires all week just makes the fast bike(s) feel that much faster, although I have to slaughter myself keeping up with the kid when we commute together. The good part about performance tire is that they have softer compounds and typically better wet grip. You get the super-hard, long-wearing tread compounds, and they're slippery on wet pavement.

-- Jay Beattie.


My Maxxi tubeless tires road awful and felt like they were sticking to the ground at 100 and 90 psi but felt pretty good at 80.
Ads
  #72  
Old February 21st 19, 06:47 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,261
Default Conbtinental has come out with a GP5000S and a GP5000TL

On Wednesday, February 20, 2019 at 4:09:05 PM UTC-8, John B. Slocomb wrote:
On Wed, 20 Feb 2019 10:21:21 -0800 (PST), wrote:

On Wednesday, February 20, 2019 at 9:56:55 AM UTC-8, duane wrote:
On 20/02/2019 10:50 a.m., Joerg wrote:
On 2019-02-18 08:39, Duane wrote:
On 18/02/2019 10:16 a.m., Joerg wrote:
On 2019-02-18 05:35, Duane wrote:
On 17/02/2019 10:57 a.m., Joerg wrote:
On 2019-02-11 15:32,
wrote:
On Sunday, February 10, 2019 at 4:54:06 PM UTC-8, Duane wrote:
wrote:
On Sunday, February 10, 2019 at 3:52:27 PM UTC+1, Duane wrote:
wrote:
On Saturday, February 9, 2019 at 7:56:22 PM UTC+1, Joerg
wrote:
On 2019-02-09 09:52,
wrote:


I learned pretty soon that paying more than $20 for a road
bike tire is a waste of money. In fact, they can be worse
than expensive tires. Similar for MTB tires.

That depends on your riding conditions and requirements. I
ride on good roads on my road bikes and get 4500 km out of a
Continental 4000S(2) rear tire and expect the same from the
5000 so price is not that important.

Lou



I get about the same mileage and very few flats.Â* I think I’ve
had one flat in the last 10,000km and that was a tube giving
out when I hit a pothole hard.Â* I ride on roads but I can’t say
they’re always good roads.

Maybe Joerg is riding his road bike on single track carrying 4
gallons of water or something...


1-1/2 gallons max, on hot summer days. This is required on some rides
unless you carry chlorine tablets, can stomach that taste _and_
suppress any thoughts about what you've seen in the river during
kayaking further upstream.


So you're riding a road bike on single track carrying 1-1/2 gallons of
water.Â* Maybe you have the wrong bike for that.


No, I use a 29" FS MTB for that. What I am saying is that the problem
with tires is basically the same whether road bike or MTB. Expensive
tires are designed towards light weight and performance. Then, their
sidewalls fail.


My point is that you seem to have different results from anyone I know
with respect to tires.Â* I don't know anyone doing any serious
mileage on
a road bike that thinks cheaper tires are better.


I have met lots of road bike riders who have realized that expensive
tires just aren't worth it unless you plan to participate in the Amgen
Tour, every millisecond counts and a team car is there at your beck
and call.


Saying that the additional cost is not worth the return for your
specific use case is different than saying that cheaper tires are better
than expensive tires.


They _are_ better. To be "better" isn't necessarily something that has a
better cost/performance ratio but somthing that doesn't go KAPOOF during
ride. I didn't have flats in years, neither on the MTB nor the road
bike. Mission accomplished, I'd say, and it was accomplished by
switching to Asian tires.

As I said this is different for competitive riders who get a new bike
from the team car the second a tire is flat. I do not have a team car,
do not belong to that group and never will.


Well we do have one guy that buys chinese knock off tires online.Â* He's
had so many split tires that we are contemplating a GoFundMe page for
him so we don't have to keep stopping to put boots in his tires....


Very different here. The rolling surface does wear down within 2000mi
which is slighlty lower than the 2500mi I could milk out of a
Gatorskin. However, I get 2000mi out of every tire while I only got
around 1000mi out of the Gatorskins where the sidewalls blew.


Are you talking about single track now or are you saying your roads wear
tires down more than say Quebec roads?Â* Hard to keep track.Â* And do the
Gatorskin tires just blow sidewalls or are you running into ruts or
something?


Again, my statement goes for _both_ road and offroad. I do not know
Quebec roads but ours in California have a lot of debris and are often
in very poor condition. Pieces of asphalt broken out and laying on top
and such. The result of inept government.


https://www.google.ca/search?q=quebe...CAAQCA#imgrc=_

Here it's partially the government, partially the +/-40 C temperature
swings and partially the mob supplying the asphalt.

We seem to get by without your tire issues for the most part. I'm
getting ~5000km from my Conti 4000s and rarely get flats.

I try to avoid potholes but I have hit one that caused my tube to split
but I haven't cut a sidewall yet. This happens when you ride in a tight
group and the guy in front of you moves to avoid the hole at the last
second without warning. But you say you keep yards between you and any
other riders so it's hard to understand your issues.

Whatever. Use what works for you.

On trails the tire torture is of more natural causes, decomposed granite
and sharp rocks, some embedded and some rolling. Then both on roads and
trails there are these which go into runnig surfaces and sometimes side
walls:

https://en.wikipedia.org/wiki/Goat%2...idum_seeds.jpg



If you're talking about trail riding then why do you say road bike? I
don't ride my Tarmac on single track unless I can't avoid it which is never.

A bike shop owner told me that they aren't native but came in from
places like Arizona just a few years ago. Anyhow, we've got to deal with
all that.


All this assumes a tire liner so I can ride tires down to their "last
mile". In goat's head thorn country wheer I live a liner is the
prudent to do anyhow.

Not sure what you mean by a tire liner. ...


This:

https://www.amazon.com/Mr-Tuffy-Bicy.../dp/B078FHD1ZH

Worth every penny.


Â*... It's not like they are optional as far as I know.


They are optional. Some tires (supposedly) have something similar built
in but my experience is that it fails as soon as the thorn or whatever
hits far enough off-center.

In addition I have thick thron-resistant tubes in the MTB and road bike
tires. For the MTB the tire liner is then sleeved by a reguar good
quality tube with the valve stem removed and slit. That combination
seems to be indestructable. Which was my goal.


My experience with cheap tires was absolutely horrible. They flatted if you look sideways at them and they wore out so rapidly that they cost more than using more expensive longer wearing tires.

I'm sort of wondering just how far over the edge that Joerg is willing to take his tires before replacing them. I very rarely get more than 2,500 miles on the very longest wearing tires. I believe that he is approximately my size and yet he gets almost twice that distance if I understand him correctly.

Or we can go with Frank's previous claim that the graphene layer in my Vittoria tires doesn't protect anything because a layer only 8 molecules thick couldn't possibly protect anything.

http://www.ukm.my/jsm/pdf_files/SM-P...in%20Chong.pdf

This was a test in medical gloves that have to have several times the stretch of tires and yet even the very small pieces of graphene yielded an 11% increase in puncture resistance.


Actually, if you actually read the study it showed that a thickness of
0.0177" provided the greatest resistance.

Please note that this is substantially thicker then the 8 molecules
you mention above.

And, of course, Frank denies that he ever said such a thing so is this
yet another example of "The Sky is Falling! The Sky is Falling!"?

--
Cheers,
John B.


These gloves were bult not with a sheet in the gloves but with particles. That means that in order to cover as much space as possible without harming the required flexibility they placed the largest pieces of graphene in there possible.

Do you think that needle pricks in hospital conditions is something not to worry about? If Frank didn't make that comment about graphene not stopping anything because it was only a molecule thick than you or one of your other argument makers did.
  #73  
Old February 21st 19, 06:52 PM posted to rec.bicycles.tech
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Posts: 1,261
Default Conbtinental has come out with a GP5000S and a GP5000TL

On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote:
On 2/20/2019 6:30 PM, jbeattie wrote:

Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire.


It might be interesting to try some simple coast-down tests. If you have
any hills with pretty consistent slope but not too steep, you could run
them at (say) 75 psi and coast down noting your time between two
landmarks. Then ride back up, inflate to 90 and repeat the trial. If
done on a day without wind, you'd probably get a realistic estimate of
how rolling resistance varies with those two pressures.

You say you don't use cyclometers. But those with cyclometers mounted
might just use the speeds indicated to tell the difference.


--
- Frank Krygowski


Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared.
  #74  
Old February 21st 19, 07:57 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default Conbtinental has come out with a GP5000S and a GP5000TL

On 2019-02-21 09:38, wrote:
On Wednesday, February 20, 2019 at 12:44:59 PM UTC-8, Joerg wrote:
On 2019-02-20 10:21,
wrote:

[...]


Or we can go with Frank's previous claim that the graphene layer
in my Vittoria tires doesn't protect anything because a layer
only 8 molecules thick couldn't possibly protect anything.

http://www.ukm.my/jsm/pdf_files/SM-P...in%20Chong.pdf



This was a test in medical gloves that have to have several times
the stretch of tires and yet even the very small pieces of
graphene yielded an 11% increase in puncture resistance.

The Vittoria tires have overlapping sheets of the material making
it very puncture resistant. Now these most certainly aren't in
the realm of Joerg's "cheap tires" but they are made in
Thailand.


Including shipping I paid $12/ea for the Vittoria Zafiros. That
qualifies as low cost in my book. Jay wrote they don't last but I
get well north of 1500mi out of them and I am not babying my road
bike. It rolls over some nasty stuff. So if there was another sale
and I needed to restock on tires I'd buy those again.

-- Regards, Joerg

http://www.analogconsultants.com/


When I tried the Zafiros I started getting flats within 500 miles.
That's why I was very hesitant to try the higher priced Vittorias.
But the G+ tires seem really great so far.


This is one of the reasons why I use tire liners. No flats ever with the
Zafiros and I wear them down to bare minimums. Or past that. They have
no TWI so one never really knows when they are finished. When you never
get flats you can't feel the remaining thickness because the tire never
comes off until it's worn.

--
Regards, Joerg

http://www.analogconsultants.com/
  #75  
Old February 21st 19, 10:10 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Conbtinental has come out with a GP5000S and a GP5000TL

On 2/21/2019 12:52 PM, wrote:
On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote:
On 2/20/2019 6:30 PM, jbeattie wrote:

Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire.


It might be interesting to try some simple coast-down tests. If you have
any hills with pretty consistent slope but not too steep, you could run
them at (say) 75 psi and coast down noting your time between two
landmarks. Then ride back up, inflate to 90 and repeat the trial. If
done on a day without wind, you'd probably get a realistic estimate of
how rolling resistance varies with those two pressures.

You say you don't use cyclometers. But those with cyclometers mounted
might just use the speeds indicated to tell the difference.


--
- Frank Krygowski


Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared.


When you say the road "would flatten out" do you mean it was horizontal,
instead of downhill? Or do you mean the bumps went away and it remained
downhill?


--
- Frank Krygowski
  #76  
Old February 21st 19, 10:27 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,261
Default Conbtinental has come out with a GP5000S and a GP5000TL

On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 12:52 PM, wrote:
On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote:
On 2/20/2019 6:30 PM, jbeattie wrote:

Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire.

It might be interesting to try some simple coast-down tests. If you have
any hills with pretty consistent slope but not too steep, you could run
them at (say) 75 psi and coast down noting your time between two
landmarks. Then ride back up, inflate to 90 and repeat the trial. If
done on a day without wind, you'd probably get a realistic estimate of
how rolling resistance varies with those two pressures.

You say you don't use cyclometers. But those with cyclometers mounted
might just use the speeds indicated to tell the difference.


--
- Frank Krygowski


Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared.


When you say the road "would flatten out" do you mean it was horizontal,
instead of downhill? Or do you mean the bumps went away and it remained
downhill?


--
- Frank Krygowski


It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road.
  #77  
Old February 21st 19, 10:46 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Conbtinental has come out with a GP5000S and a GP5000TL

On 2/21/2019 4:27 PM, wrote:
On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 12:52 PM,
wrote:
On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote:
On 2/20/2019 6:30 PM, jbeattie wrote:

Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire.

It might be interesting to try some simple coast-down tests. If you have
any hills with pretty consistent slope but not too steep, you could run
them at (say) 75 psi and coast down noting your time between two
landmarks. Then ride back up, inflate to 90 and repeat the trial. If
done on a day without wind, you'd probably get a realistic estimate of
how rolling resistance varies with those two pressures.

You say you don't use cyclometers. But those with cyclometers mounted
might just use the speeds indicated to tell the difference.


--
- Frank Krygowski

Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared.


When you say the road "would flatten out" do you mean it was horizontal,
instead of downhill? Or do you mean the bumps went away and it remained
downhill?


--
- Frank Krygowski


It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road.


OK, if you were coasting and you had no tailwind that exceeded your
speed, you had nobody pushing you forward (which I've done for people
many times), and you had no rope towing you or some other weird situation...

And your bike actually accelerated when the road was horizontal? Yes,
that's impossible. Sorry, Tom, this is basic physics.

(And I had to include the rope tow because that was Jute's "deus ex
machina" on his first weird braggart tale here.)

Your story does, however, indicate the power of suggestion and how it
can mess with our perceptions.

--
- Frank Krygowski
  #78  
Old February 22nd 19, 06:31 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,261
Default Conbtinental has come out with a GP5000S and a GP5000TL

On Thursday, February 21, 2019 at 1:46:38 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 4:27 PM, wrote:
On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 12:52 PM,
wrote:
On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote:
On 2/20/2019 6:30 PM, jbeattie wrote:

Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire.

It might be interesting to try some simple coast-down tests. If you have
any hills with pretty consistent slope but not too steep, you could run
them at (say) 75 psi and coast down noting your time between two
landmarks. Then ride back up, inflate to 90 and repeat the trial. If
done on a day without wind, you'd probably get a realistic estimate of
how rolling resistance varies with those two pressures.

You say you don't use cyclometers. But those with cyclometers mounted
might just use the speeds indicated to tell the difference.


--
- Frank Krygowski

Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared.

When you say the road "would flatten out" do you mean it was horizontal,
instead of downhill? Or do you mean the bumps went away and it remained
downhill?


--
- Frank Krygowski


It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road.


OK, if you were coasting and you had no tailwind that exceeded your
speed, you had nobody pushing you forward (which I've done for people
many times), and you had no rope towing you or some other weird situation....

And your bike actually accelerated when the road was horizontal? Yes,
that's impossible. Sorry, Tom, this is basic physics.

(And I had to include the rope tow because that was Jute's "deus ex
machina" on his first weird braggart tale here.)

Your story does, however, indicate the power of suggestion and how it
can mess with our perceptions.

--
- Frank Krygowski


Frank, if this is against physics why haven't you actually explained this to us?

To my way of thinking if E = 1/2M*V^2 and you reduce the rolling resistance you coast for a longer distance to expend the energy. But that isn't what happened. As I said - when I hit the smooth pavement the bike increased its speed.

This was not a single case but multiple experiments and as the smooth pavement degraded over the summer and grew rougher the increasing speed disappeared at least to the level where it wasn't detectable.
  #79  
Old February 22nd 19, 07:39 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 824
Default Conbtinental has come out with a GP5000S and a GP5000TL

On Friday, February 22, 2019 at 6:31:09 PM UTC+1, wrote:
On Thursday, February 21, 2019 at 1:46:38 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 4:27 PM, wrote:
On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 12:52 PM,
wrote:
On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote:
On 2/20/2019 6:30 PM, jbeattie wrote:

Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire.

It might be interesting to try some simple coast-down tests. If you have
any hills with pretty consistent slope but not too steep, you could run
them at (say) 75 psi and coast down noting your time between two
landmarks. Then ride back up, inflate to 90 and repeat the trial. If
done on a day without wind, you'd probably get a realistic estimate of
how rolling resistance varies with those two pressures.

You say you don't use cyclometers. But those with cyclometers mounted
might just use the speeds indicated to tell the difference.


--
- Frank Krygowski

Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared.

When you say the road "would flatten out" do you mean it was horizontal,
instead of downhill? Or do you mean the bumps went away and it remained
downhill?


--
- Frank Krygowski

It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road.


OK, if you were coasting and you had no tailwind that exceeded your
speed, you had nobody pushing you forward (which I've done for people
many times), and you had no rope towing you or some other weird situation...

And your bike actually accelerated when the road was horizontal? Yes,
that's impossible. Sorry, Tom, this is basic physics.

(And I had to include the rope tow because that was Jute's "deus ex
machina" on his first weird braggart tale here.)

Your story does, however, indicate the power of suggestion and how it
can mess with our perceptions.

--
- Frank Krygowski


Frank, if this is against physics why haven't you actually explained this to us?

To my way of thinking if E = 1/2M*V^2 and you reduce the rolling resistance you coast for a longer distance to expend the energy. But that isn't what happened. As I said - when I hit the smooth pavement the bike increased its speed.

This was not a single case but multiple experiments and as the smooth pavement degraded over the summer and grew rougher the increasing speed disappeared at least to the level where it wasn't detectable.


I think what Frank tries to say is that to be able to accelerate there must be a driving force, one of Newtons laws. If you are coasting on flat terrain without a tailwind there is no driving force.

Lou
  #80  
Old February 22nd 19, 08:25 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Conbtinental has come out with a GP5000S and a GP5000TL

On 2/22/2019 1:39 PM, wrote:
On Friday, February 22, 2019 at 6:31:09 PM UTC+1, wrote:
On Thursday, February 21, 2019 at 1:46:38 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 4:27 PM,
wrote:
On Thursday, February 21, 2019 at 1:10:42 PM UTC-8, Frank Krygowski wrote:
On 2/21/2019 12:52 PM,
wrote:
On Wednesday, February 20, 2019 at 4:32:10 PM UTC-8, Frank Krygowski wrote:
On 2/20/2019 6:30 PM, jbeattie wrote:

Another thing about these tires is that they have a pretty high recommended inflation pressure for a 32mm. IIRC around 90 PSI, which makes the ride like rocks, but if they are under inflated, they ride like slugs. A 10-15 psi difference really affects the perceived "speed" of the tire.

It might be interesting to try some simple coast-down tests. If you have
any hills with pretty consistent slope but not too steep, you could run
them at (say) 75 psi and coast down noting your time between two
landmarks. Then ride back up, inflate to 90 and repeat the trial. If
done on a day without wind, you'd probably get a realistic estimate of
how rolling resistance varies with those two pressures.

You say you don't use cyclometers. But those with cyclometers mounted
might just use the speeds indicated to tell the difference.


--
- Frank Krygowski

Remember that I was describing the coast down test I had up in Cull Canyon where I would coast down a really rough section of road and then it would flatten out and when I hit a 100 yard long patch of new and very smooth pavement the bike would actually accelerate? Everyone wanted to argue that wasn't possible but I did it again and again. As the summer wore on the asphalt aged and got rougher and though it was still pretty smooth the effect had disappeared.

When you say the road "would flatten out" do you mean it was horizontal,
instead of downhill? Or do you mean the bumps went away and it remained
downhill?


--
- Frank Krygowski

It went downhill on a very rough road, flattened to horizontal or at least the 0% grade indication on my altimeter and then it climbed a bit before descending a bike. The increase in speed was immediate upon entering the smooth section and not a slow build up of speed as would come from a declining road.

OK, if you were coasting and you had no tailwind that exceeded your
speed, you had nobody pushing you forward (which I've done for people
many times), and you had no rope towing you or some other weird situation...

And your bike actually accelerated when the road was horizontal? Yes,
that's impossible. Sorry, Tom, this is basic physics.

(And I had to include the rope tow because that was Jute's "deus ex
machina" on his first weird braggart tale here.)

Your story does, however, indicate the power of suggestion and how it
can mess with our perceptions.

--
- Frank Krygowski


Frank, if this is against physics why haven't you actually explained this to us?

To my way of thinking if E = 1/2M*V^2 and you reduce the rolling resistance you coast for a longer distance to expend the energy. But that isn't what happened. As I said - when I hit the smooth pavement the bike increased its speed.

This was not a single case but multiple experiments and as the smooth pavement degraded over the summer and grew rougher the increasing speed disappeared at least to the level where it wasn't detectable.


I think what Frank tries to say is that to be able to accelerate there must be a driving force, one of Newtons laws. If you are coasting on flat terrain without a tailwind there is no driving force.


Exactly. In fact, there are retarding forces, those being air resistance
and rolling resistance, at a minimum.

And as to Tom's question, why haven't I explained it? I guess I
foolishly persist in believing that some things are obvious to educated
people.


--
- Frank Krygowski
 




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