Electronic shifting system

Tom Kunich wrote:
"Simon Brooke" wrote in message
...
in message .net, Tom
Kunich ('cyclintom@yahoo. com') wrote:

Bret - what is the power costs to run a stepping motor mechanism strong
enough to shift and maintain positioning of a chain on a bicycle for the
length of one day?

What is the need to run a stepper motor when you're sitting on top of a
jockey wheel being powered by 0.4Kw of cyclist, and which power you can
tap just by releasing a clutch?

Maybe you missed the resident genius Kveck telling us that there wasn't
any clutches in the Mektronic.

The power is there for the asking. All you need to do is to control
when to
ask it.

Indeed but the group was talking about using a stepping motor to
precisely position the RD so that they wouldn't have to turn the
adjusting screw a quarter turn once a year between tune-ups.

that's highly revealing - if you can make a comment like that, you
clearly don't do any serious mileage.


Simon, it is apparent that you have some education in mechanical design.
This whole argument began when I said that there wasn't anything to GAIN
by going to electronic shifting. It's only another failure point in an
otherwise highly reliable machine.

er, one of my cars has an electronically managed stepping motor that
controls the engine's idle speed. it's 19 years old. and it works
perfectly. now, where's this illusory bull**** about reliability come from?

But jim beam (named apparently from
what he is under the influence of ) seems to believe that derailleurs
which are almost the perfect mechanism, can be markedly improved with
electronics.

The power needed by the control electronics can be in terms of
fractions of a watt, and that too can be derived directly from the chain
without need for anything more than a capacitor to buffer the power.

Well, not quite but I agree that you don't need a lot of power if you're
willing to rob most of it from the drive train. But then you're either
stuck with the Mektronic mechanism which has fixed stops or complex
sensors and micro-adjustable position sensors which in the end would be
quite a pain in the neck without adding anything to reliability,
reducing costs or weight.

eh?


The modern bicycle is the end result of a hundred and fifty years of
evolution. It achieved it's peak in the 1960's and everything added
since then has been only for performance on smooth roads.

eh?


It is possible to build reliable carbon bikes but not with a significant
reduction in weight.

eh?

That isn't to say that there aren't certain
advantages to carbon bikes but there are significant disadvantages as
well. It is pretty difficult to beat a good well designed steel bike
from Bob Jackson or Waterford. (Queue in Donnelly's calculation showing
that the difference in weight can save 2 seconds on the Stelvio.)

what a crock!

"jim beam" wrote in message
t...
Tom Kunich wrote:
"jim beam" wrote in message
...
Tom Kunich wrote:
"jim beam" wrote in message
...

eh? if you can have the kind of proximity detector that cars use for
antilock brakes, or even detect fingers on mousepads, why can't you
detect the position of 10 disks with nice convenient pulse fingers on
them?

What exactly does this have to do with detecting whether a flayling
chain is centered on the cog in the small middle or large ring?

eh? a conventional derailleur doesn't do that. and an indexed
derailleur /can't/ do that.

Psst - they don't NEED to do that. Again, WHAT are you gaining if you go
to electronic shifting?

psst - in what way could a properly designed self-adjusting system
possibly shift worse than a manual system?

WHAT IS SELF ADJUSTING? Are you stupid or something?

Please explain to us what sort of clearances are in today's 10-speed
setups.

red herring.

I didn't expect you to understand the problem and you just proved it.

it's not a clearance issue guy!!! it's an issue of determining basis
coordinates and positioning accordingly. a red herring is still a red
herring regardless of specious allusions.

Proving yet again that you simply don't grasp the engineering issues.

but you have that same issue with cars. even donuts on mousepads.

You really don't understand what you're talking about.

yes i do. you were bleating about ability to detect proximity. in both
the above examples, solutions are cheap and robust. just like would be
required for a derailleur.

No - YOU were bleating about "self adjusting". Proximity has nothing to
do with that but you aren't able to understand the problem from an
engineering perspective.

you really don't get it. if you wanted a self-adjusting system, you'd
/have/ to detect proximity. duh.

You're getting funnier by the posting. But by all means keep it up. I'm
getting the giggles watching you post "proximity" after saying "it's not a
clearance issue".

weight != strength. red herrings about alleged crash injuries have
NOTHING to do derailleurs or mechanism weights.

Perhaps you can explain that?

sure - it's easy. weight != strength! you say you're an engineer, right?

See my comment above.

jim beam writes:

Tom Kunich wrote:

Indeed but the group was talking about using a stepping motor to
precisely position the RD so that they wouldn't have to turn the
adjusting screw a quarter turn once a year between tune-ups.

that's highly revealing - if you can make a comment like that, you
clearly don't do any serious mileage.

What's serious mileage? I can recall adjusting the rear derailleur of
my Campy 9 speed maybe three times in the last 7 years, and those were
after complete overhauls. I didn't have a bike computer for most of
those years (so mileage estimates are just that), and for some of them
was splitting riding time with the Moulton, but I've got at least
20,000 miles on it. Maybe my memory is failing, or the context is
different (road bike vs mountain bike). How often do most people
adjust a Campy rear derailleur?

--
Joe Riel

On Aug 11, 2:05 pm, jim beam wrote:
Tom Kunich wrote:
"jim beam" wrote
Tom Kunich wrote:
"jim beam" wrote

eh?
What exactly does this have to do with
eh?
Psst - they don't NEED to do that. Again, WHAT
psst - in what way
Please explain to us
red herring.
I didn't expect you to understand the problem and you just proved it.
it's not a clearance issue guy!!! ... a red herring is still a red
herring regardless of specious allusions.
You really don't understand what you're talking about.

yes i do. you were bleating
No - YOU were bleating about "self adjusting". ...
but you aren't able to understand the problem from an
engineering perspective.

you really don't get it. ... duh.

who said that?
Where are you getting the idea
ok, now you're becoming irrational.
You are the one that hasn't a clue of the world around you. Perhaps you
ought to learn something before pretending you know about it.

er, perhaps you're looking in a mirror when saying that?

As I pointed out in early July,
weight != strength. red herrings
Perhaps you can explain that?
sure - it's easy. weight != strength! you say you're an engineer, right?


Help! The RBR bot is arguing with the RBT bot!
It's a cascade of doom!1!! Bob Schwartz, you
gotta unplug Skynet before it's too late!!


Ben
RBR Autonomous Systems Engineer
and Giant Robot Mechanic, ASE

"jim beam" wrote in message
...

that's highly revealing - if you can make a comment like that, you clearly
don't do any serious mileage.

I'm at 4500 miles right now - what about you?

er, one of my cars has an electronically managed stepping motor that
controls the engine's idle speed. it's 19 years old. and it works
perfectly. now, where's this illusory bull**** about reliability come
from?

Why don't you make and market one of these wonderful electronic shifters
you're talking about. Or are you all talk?

The modern bicycle is the end result of a hundred and fifty years of
evolution. It achieved it's peak in the 1960's and everything added since
then has been only for performance on smooth roads.

eh?

Oh yeah, you're one of those guys who thinks that a 19 year old car is old.

It is possible to build reliable carbon bikes but not with a significant
reduction in weight.

eh?

I have a Look KG, a Time VXR and a Colnago C40. What is your experience
again?

"Joe Riel" wrote in message
...
jim beam writes:

Tom Kunich wrote:

Indeed but the group was talking about using a stepping motor to
precisely position the RD so that they wouldn't have to turn the
adjusting screw a quarter turn once a year between tune-ups.

that's highly revealing - if you can make a comment like that, you
clearly don't do any serious mileage.

What's serious mileage? I can recall adjusting the rear derailleur of
my Campy 9 speed maybe three times in the last 7 years, and those were
after complete overhauls. I didn't have a bike computer for most of
those years (so mileage estimates are just that), and for some of them
was splitting riding time with the Moulton, but I've got at least
20,000 miles on it. Maybe my memory is failing, or the context is
different (road bike vs mountain bike). How often do most people
adjust a Campy rear derailleur?

If you keep the drive train clean and lubed, almost never.

Tom Kunich wrote:
"jim beam" wrote in message
t...
Tom Kunich wrote:
"jim beam" wrote in message
...
Tom Kunich wrote:
"jim beam" wrote in message
...

eh? if you can have the kind of proximity detector that cars use
for antilock brakes, or even detect fingers on mousepads, why
can't you detect the position of 10 disks with nice convenient
pulse fingers on them?

What exactly does this have to do with detecting whether a flayling
chain is centered on the cog in the small middle or large ring?

eh? a conventional derailleur doesn't do that. and an indexed
derailleur /can't/ do that.

Psst - they don't NEED to do that. Again, WHAT are you gaining if you
go to electronic shifting?

psst - in what way could a properly designed self-adjusting system
possibly shift worse than a manual system?

WHAT IS SELF ADJUSTING? Are you stupid or something?

Please explain to us what sort of clearances are in today's
10-speed setups.

red herring.

I didn't expect you to understand the problem and you just proved it.

it's not a clearance issue guy!!! it's an issue of determining basis
coordinates and positioning accordingly. a red herring is still a red
herring regardless of specious allusions.

Proving yet again that you simply don't grasp the engineering issues.

but you have that same issue with cars. even donuts on mousepads.

You really don't understand what you're talking about.

yes i do. you were bleating about ability to detect proximity. in
both the above examples, solutions are cheap and robust. just like
would be required for a derailleur.

No - YOU were bleating about "self adjusting". Proximity has nothing
to do with that but you aren't able to understand the problem from an
engineering perspective.

you really don't get it. if you wanted a self-adjusting system, you'd
/have/ to detect proximity. duh.

You're getting funnier by the posting. But by all means keep it up. I'm
getting the giggles watching you post "proximity" after saying "it's not
a clearance issue".

weight != strength. red herrings about alleged crash injuries have
NOTHING to do derailleurs or mechanism weights.

Perhaps you can explain that?

sure - it's easy. weight != strength! you say you're an engineer,
right?

See my comment above.


dude, if you want to make a technical point, why do you descend in to
bull**** arguments about weight and materials - which are untrue?

instead, all you're doing is descending deeper into some kind of bizarre
ad hominem [nonsense] defense of a total non-position.

get with the tech of proximity detection and control or move along.

Joe Riel wrote:
jim beam writes:

Tom Kunich wrote:
Indeed but the group was talking about using a stepping motor to
precisely position the RD so that they wouldn't have to turn the
adjusting screw a quarter turn once a year between tune-ups.
that's highly revealing - if you can make a comment like that, you
clearly don't do any serious mileage.

What's serious mileage? I can recall adjusting the rear derailleur of
my Campy 9 speed maybe three times in the last 7 years, and those were
after complete overhauls. I didn't have a bike computer for most of
those years (so mileage estimates are just that), and for some of them
was splitting riding time with the Moulton, but I've got at least
20,000 miles on it. Maybe my memory is failing, or the context is
different (road bike vs mountain bike). How often do most people
adjust a Campy rear derailleur?


for me, if i put on new cable outers, within the first 10 miles, then
50, than about 200. lasts about every 1000 thereafter. if i do cable
inners only, every 1000 or so. but i like my stuff to be dead on.

in message . net, Tom
Kunich ('cyclintom@yahoo. com') wrote:

"Simon Brooke" wrote in message
...
in message .net, Tom
Kunich ('cyclintom@yahoo. com') wrote:

Bret - what is the power costs to run a stepping motor mechanism strong
enough to shift and maintain positioning of a chain on a bicycle for
the length of one day?

What is the need to run a stepper motor when you're sitting on top of a
jockey wheel being powered by 0.4Kw of cyclist, and which power you can
tap just by releasing a clutch?

Maybe you missed the resident genius Kveck telling us that there wasn't
any clutches in the Mektronic.

The power is there for the asking. All you need to do is to control when
to
ask it.

Indeed but the group was talking about using a stepping motor to
precisely position the RD so that they wouldn't have to turn the
adjusting screw a quarter turn once a year between tune-ups.

Simon, it is apparent that you have some education in mechanical design.
This whole argument began when I said that there wasn't anything to GAIN
by going to electronic shifting. It's only another failure point in an
otherwise highly reliable machine. But jim beam (named apparently from
what he is under the influence of ) seems to believe that derailleurs
which are almost the perfect mechanism, can be markedly improved with
electronics.

OK, I hear what you're saying and I'm not sure I agree. It's partly because
I'm a geek and like playing with toys. But also, one of my bikes - the one
I ride to work most days - is an old steel Raleigh. It suffers from frame
flex. And one of the problems that frame flex causes is that because the
parallelogram is attached to the back of the frame, and controlled by a
bit of wire that is under tension from the front of the frame, as the
front of the frame and the back of the frame move relative to one another
you get ghost shifts. This is exacerbated on my Raleigh, of course, by the
fact that it was designed for a five speed freewheel and now has a nine
speed cassette, so smaller distortions of the frame cause ghostshifts than
would have been the case when it was new...

With modern, closer tolerance derailleur trains the derailleur cage is
still attached to the back of the frame but the detents which control its
position are in the shifter mechanism at the front of the frame (or,
actually, on the handlebar...). Modern frames are not made out of wet
spaghetti, of course, but they still flex - and there are reasons why it's
good that they flex a bit in controlled ways. And the cables bend through
tighter and more relaxed radii as the steering moves, and so on. And this
causes the pantograph to move, and this causes the cage to move... And
from an engineering point of view this is just wrong.

The detents really ought to be in the derailleur mechanism itself.

[As an aside a pantograph is not really the ideal mechanism for something
that wants to track across a cassette at a fixed distance from the cogs -
particularly on a machine on which different sized cassettes may be used.
The optimum trajectory for a 12-21 cassette is quite different from that
for a 13-26 cassette. Mind you, I'm not saying I could design a better]

If the detents are going to be in the derailleur mechanism, then an
electronically triggered movement is quite a good idea. I can imagine a
mechanical system where a short tug on the cable released the mechanism
one detent, and a longer tug on the cable lifted the mechanism one detent,
with a user interface much like the SRAM 'double tap' (the cable being
slack between actuations). But an advantage of electronic actuation, as
Mektronic demonstrated, is you can have multiple switch positions so that
it becomes easy to change gear from the tops as well as the hoods and the
drops. And if you have electronic actuation, then taking the energy to
lift the mechanism from the chain seems to me clever and cool.

Also, it's easy to build an electrical wiring harness into a carbon
composite structure. Thus exposed cables could be a thing of the past, and
I'd see that as a positive thing.

The power needed by the control electronics can be in terms of
fractions of a watt, and that too can be derived directly from the chain
without need for anything more than a capacitor to buffer the power.

Well, not quite but I agree that you don't need a lot of power if you're
willing to rob most of it from the drive train. But then you're either
stuck with the Mektronic mechanism which has fixed stops or complex
sensors and micro-adjustable position sensors which in the end would be
quite a pain in the neck without adding anything to reliability, reducing
costs or weight.

I certainly think that if you're going to have electronic gear actuation on
a racing bike in a sporting context then the energy used to lift the
mechanism ought to come from the competitor's muscular effort in near real
time - if you're using stored power from a battery charged before the
event that ought to be seen as cheating.

The modern bicycle is the end result of a hundred and fifty years of
evolution. It achieved it's peak in the 1960's and everything added since
then has been only for performance on smooth roads.

I'm not at all sure I agree with that. I have two road bikes I ride
regularly, a modern carbon Dolan and the fifteen-year-old steel Raleigh.
The Dolan performs better than the Raleigh in every department. The slant
parallelogram was a significant improvement; the indexed shifter was a
significant improvement; integrating the shifter and the brake lever was a
significant improvement. All these things have happened in the past twenty
years. And none of them is as significant as the development of the carbon
monocoque frame.

But what's held cycling development back has been the luddite sabutage by
the UCI of any significant technical improvement. It's ludicrous, for
example, that we're still not riding bikes with monoblades front and
back - aerodynamics would be better, and changing wheels in race
conditions would be enormously faster (and you wouldn't need different
spare wheels for front and rear).

It is possible to build reliable carbon bikes but not with a significant
reduction in weight.

True. But the benefits of carbon aren't mainly about weight, in my opinion;
they're mainly about how precisely you can design the stiffness and
compliance of different parts of the structure. A good carbon frame may
weigh only a little less than a good steel one, but it can be much stiffer
laterally while being even more compliant vertically.

That isn't to say that there aren't certain
advantages to carbon bikes but there are significant disadvantages as
well. It is pretty difficult to beat a good well designed steel bike from
Bob Jackson or Waterford. (Queue in Donnelly's calculation showing that
the difference in weight can save 2 seconds on the Stelvio.)

Yup, but the difference in not ghost-shifting when you're out of the saddle
and stomping can make far more than that!

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

;; I'd rather live in sybar-space

in message , Joe Riel ') wrote:

jim beam writes:

Tom Kunich wrote:

Indeed but the group was talking about using a stepping motor to
precisely position the RD so that they wouldn't have to turn the
adjusting screw a quarter turn once a year between tune-ups.

that's highly revealing - if you can make a comment like that, you
clearly don't do any serious mileage.

What's serious mileage? I can recall adjusting the rear derailleur of
my Campy 9 speed maybe three times in the last 7 years, and those were
after complete overhauls. I didn't have a bike computer for most of
those years (so mileage estimates are just that), and for some of them
was splitting riding time with the Moulton, but I've got at least
20,000 miles on it. Maybe my memory is failing, or the context is
different (road bike vs mountain bike). How often do most people
adjust a Campy rear derailleur?

He probably uses Shimano... ;-)

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

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