CVT interest

Quoted message said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

I think it would be terrific, if it really had no efficiency loss and no
weight penalty. However, there is nothing yet available that comes
close to meeting that standard.

I also think that you are some sort of troll, because you are writing
anonymously about some scheme to get cyclists to transfer money to you.

I think you should be more upfront. Do you have some links or detailed
descriptions of the mechanism?

--
Ted Bennett

Ted Bennett said:

Quoted message said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

I think it would be terrific, if it really had no efficiency loss and no
weight penalty. However, there is nothing yet available that comes
close to meeting that standard.

I also think that you are some sort of troll, because you are writing
anonymously about some scheme to get cyclists to transfer money to you.

I think you should be more upfront. Do you have some links or detailed
descriptions of the mechanism?

--
Ted Bennett

I am in the process of developing such a device. I was trying to get
an idea of the market interest before I begin funding the prototype, as
I am funding the project with my own money. I did not post that to
begin with because I wanted responces about a desire for the concept,
not a debate about weather or not people think I actually have a design
that works. I will not post a description of the mechanism. Thanks
for your responce.

Tim Knodel

Quoted message said:

Ted Bennett said:

Quoted message said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

I think it would be terrific, if it really had no efficiency loss and no
weight penalty. However, there is nothing yet available that comes
close to meeting that standard.

I also think that you are some sort of troll, because you are writing
anonymously about some scheme to get cyclists to transfer money to you.

I think you should be more upfront. Do you have some links or detailed
descriptions of the mechanism?

--
Ted Bennett

I am in the process of developing such a device. I was trying to get
an idea of the market interest before I begin funding the prototype, as
I am funding the project with my own money. I did not post that to
begin with because I wanted responces about a desire for the concept,
not a debate about weather or not people think I actually have a design
that works. I will not post a description of the mechanism. Thanks
for your responce.

Tim Knodel

Dear Tim,

Before you try to re-invent a wheel that's repeatedly failed to work
well, you might browse through these threads:

http://groups.google.com/group/rec.bicycles.tech/search?q=cvt+efficiency&start=0&scoring=d&

There's plenty of desire for a light, efficient, reliable CVT on a
bicycle, but no one seems to have invented one in the last century.

Cheers,

Carl Fogel

Quoted message said:

There's plenty of desire for a light, efficient, reliable CVT on a
bicycle, but no one seems to have invented one in the last century.

I'd characterize it as curiosity rather than desire. I don't really see
any market demand for such a thing. I see people thinking the Rohloff
internal gear hub is pretty cool but way too expensive for most of the
target consumers that might actually buy one otherwise; I'd guess this
CVT would get a similar reception, assuming it's as good as the OP
described.

I wouldn't invest my money in bringing it to market; my opinion is worth
nothing but he did ask.

In article
<[email hidden]>,

Quoted message said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

Power transmission efficiency of 0.92? Weight? Simplicity?
Robust? CVTs have been built, but all fail in all four
categories. I predict such a device will not happen in
the next ten years.

--
Michael Press

Quoted message said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

Well, since the stated criteria have never been approached, and are
exceptionally unlikely to be met by anything with reasonable
durability and an affordable cost, there's not much point, is there?

Seriously, every CVT thus far introduced has either failed to live up
to the claims made for it, and/or has had a short life expectancy,
and/or has been overly expensive; some combination of the three.

The record in the automotive field is similar. Hondas with a CVT have
a near-zero value at wholesale in this area; not even the least
reputable garage-lot car peddlers will take a chance on them.

If someone came to me with a claim that they had such a device, I
would regard the person as a prima facie liar. I might be polite, I
might be courteous, I might listen to the pitch, but my checkbook
would remain out of sight and I would sign nothing.

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

There used to be a bicycle called the Yankee Bike that was eventually bought
by Nordic Track before they eliminated it. The claim to fame of this bike
was a single rear rim band brake and a front crank that continuosly varied
in and out to change the gear ratios.

There was a pully/chain tensioner in the rear with a single cog. All the
"gears" were done by the movement within the crank. Several stems/teeth
would move in and move out to change the diameter of the crank.

Quoted message said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

I think it's a fantastic idea, perhaps the most exciting I've ever heard,
one that will surely revolutionize cycling. I encourage you to mortgage
your home and cash in your children's college savings accounts. You've got
a sure winner. Years from now, when grateful riders speak your name they
will do so not on their bikes but rather on the ground--because one must
needs kneel and bare one's head to show the proper reverence. I'm sure you
can succeed where so many others have failed, in part because you have
already demonstrated your keen judgement and razor sharp business acumen
by asking anonymous guys on the 'net for advice.

in message <[email hidden]>,

(') said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

/If/ you could make a true CVT with as little loss as a derailleur, I
think there'd be a lot of interest. I'd certainly be interested,
although more for mountain bikes than for road ones. I have played about
with ideas of a DAF-type opposed cone drive myself.

But a racing bicycle is a low power vehicle where inefficiencies in the
transmission make a real difference to performance, so you really would
have to make it as efficient as a derailleur system.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Due to financial constraints, the light at the end of the tunnel
has been switched off.

in message <[email hidden]>, Diablo Scott

(') said:

Quoted message said:

There's plenty of desire for a light, efficient, reliable CVT on a
bicycle, but no one seems to have invented one in the last century.

I'd characterize it as curiosity rather than desire. I don't really
see
any market demand for such a thing. I see people thinking the Rohloff
internal gear hub is pretty cool but way too expensive for most of the
target consumers that might actually buy one otherwise; I'd guess this
CVT would get a similar reception, assuming it's as good as the OP
described.

A Rohloff costs relatively little against a Record groupset, for example,
or even (from the mountain bike perspective) a really good suspension
fork. I really believe that, for mountain bikes, the Nicolai Nucleon and
the 'GBoxx' concept represent the shape of things to come, although they
need to get some weight off it. On a mountain bike, having the
transmission protected from dirt and damage has the potential to
outweigh the slightly lower efficiency of an epicyclic with separate
primary and final drive chains, even under racing conditions.

And a DAF type opposed cone CVT has inherently many fewer moving parts
than an epicyclic gearbox. Nor is it necessarily heavy. I don't think
either cost, weight or complexity are necessarily limiting factors for
bicycle CVT. But I would be worried about efficiency.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Wise man with foot in mouth use opportunity to clean toes.
;; the Worlock

Quoted message said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

Zero interest. I don't see the need for an infinitely variable
transmission -- we're not diesel engines.

Per Peter Cole:

Quoted message said:

I don't see the need for an infinitely variable
transmission -- we're not diesel engines.

My own reaction is along those lines.

I'd actually see CVT as a negative. Reason: I could vary my spin rate at a
given speed. Sometimes I like to get out of the saddle and just thump along...
other times I like to spin pretty fast, still other times.....

Bottom line, a CVT transmission would drive me nuts.
--
PeteCresswell

(PeteCresswell) said:

My own reaction is along those lines.

I'd actually see CVT as a negative. Reason: I could vary my spin
rate at a given speed. Sometimes I like to get out of the saddle
and just thump along... other times I like to spin pretty fast, still
other times.....

Bottom line, a CVT transmission would drive me nuts.

Not sure how it would work and feel on a mountain bike. Given that
mtbing has lots of power on, power off pedalling through technical
stuff, not spinning, I wonder how it would work if every time you pushed
hard on the pedal it tried to change down instead of levering the wheel
over the obstacle. Likewise when traction is poor climbing, gear
selection can be critical to not stalling or spinning the rear wheel. I
can see CVT gearing down and the rear wheel slipping all the time on the
climbs.

--
Tony

"Anyone who conducts an argument by appealing to authority is not using
his intelligence; he is just using his memory."
- Leonardo da Vinci

in message <[email hidden]>, Tony Raven

(') said:

(PeteCresswell) said:

My own reaction is along those lines.

I'd actually see CVT as a negative. Reason: I could vary my spin
rate at a given speed. Sometimes I like to get out of the saddle
and just thump along... other times I like to spin pretty fast, still
other times.....

Bottom line, a CVT transmission would drive me nuts.

Not sure how it would work and feel on a mountain bike. Given that
mtbing has lots of power on, power off pedalling through technical
stuff, not spinning, I wonder how it would work if every time you
pushed hard on the pedal it tried to change down instead of levering
the wheel
over the obstacle. Likewise when traction is poor climbing, gear
selection can be critical to not stalling or spinning the rear wheel. I
can see CVT gearing down and the rear wheel slipping all the time on
the climbs.

CVT is not the same as /automatically/ variable transmission. You could
have CVT with manual selection, or a stepped system (such as a
derailleur) with automatic selection. The two things are not related,
although it would be easy to do an automatic CVT.

However, on a mountain bike I agree that, most of the time, you would not
want it to be automatic. But continuously variable? Yes, that would be a
win. If it wouldn't, no one would want a 27 speed.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; I put the 'sexy' in 'dyslexia'

On Sat, 03 Jun 2006 08:58:25 -0400, "(PeteCresswell)" <[email hidden]>

Quoted message said:

I'd actually see CVT as a negative. Reason: I could vary my spin rate at a
given speed. Sometimes I like to get out of the saddle and just thump along...
other times I like to spin pretty fast, still other times.....

Bottom line, a CVT transmission would drive me nuts.

I started a reply along these lines - it isn't just you on different
days, or regular laps and prime laps, but it would have to be
appropriate for any rider regardless of style. However, it doesn't say
that it is an automatic, therefore (in theory) all you need is to have
positive gear-inch points.

Since it really lost me at the purported efficiency level, I didn't
bother to consider it further.

Curtis L. Russell
Odenton, MD (USA)
Just someone on two wheels...

On Sat, 03 Jun 2006 15:42:16 +0100, Tony Raven <[email hidden]>

Quoted message said:

Not sure how it would work and feel on a mountain bike. Given that
mtbing has lots of power on, power off pedalling through technical
stuff, not spinning, I wonder how it would work if every time you pushed
hard on the pedal it tried to change down instead of levering the wheel
over the obstacle.

He did say manual. You get to shift - you just need to know where to
stop on the merry-go-round. A CVT doesn't HAVE to be an automatic...

Curtis L. Russell
Odenton, MD (USA)
Just someone on two wheels...

Quoted message said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

I think its been done to death a million times and just doesnt work.
The main issue seems to be transferring the torque without squashing
things together so hard that the efficiency drops.

I remembered these guys from a while back;

http://www.fallbrooktech.com/default.asp

<shrugs> I think the market wants it, or there wouldnt be the drive for
more and more cogs on the cassette. Keeping a straight chainline is
also desirable. Internal gubbins free of the elements. Yep, it all
adds up, so there must be a damn good reason we don't have one.

"Werehatrack" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

I am curious about the amount of interest out there in both the
recreation/commuting community and the racing community for a true CVT
a manual gear system that had infinite variability, the same gear range
as a 27 speed system, no loss in efficiency and no weight gain. What
do you think?

Well, since the stated criteria have never been approached, and are
exceptionally unlikely to be met by anything with reasonable
durability and an affordable cost, there's not much point, is there?

Seriously, every CVT thus far introduced has either failed to live up
to the claims made for it, and/or has had a short life expectancy,
and/or has been overly expensive; some combination of the three.

The record in the automotive field is similar. Hondas with a CVT have
a near-zero value at wholesale in this area; not even the least
reputable garage-lot car peddlers will take a chance on them.

Hmmm... not sure about that. here in the UK a number of small cars use CVT,
and work. Honda Jazz (Fit) and Toyota Yaris for example.

I wouldn't put one on a bike though.

Quoted message said:

If someone came to me with a claim that they had such a device, I
would regard the person as a prima facie liar. I might be polite, I
might be courteous, I might listen to the pitch, but my checkbook
would remain out of sight and I would sign nothing.

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Skippy
E&OE

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I am in the process of developing such a device. I was trying to get
an idea of the market interest before I begin funding the prototype, as
I am funding the project with my own money. I did not post that to
begin with because I wanted responces about a desire for the concept,
not a debate about weather or not people think I actually have a design
that works. I will not post a description of the mechanism. Thanks
for your responce.

Tim, unless there's something in it for you I suggest not bothering. That
implies that you can make a CVT cheaper than a derailleur system with no
more losses. I sincerely doubt that you can do that.

Tom