Tech development or marketing ploy, redux

You decide:

ncbi.nlm.nih.govquery.fcgiOpen ↗
ds=12165689&dopt=Abstract

(Note that the Rotor cranks do exactly what Jim set out to accomplish with this one-legged offset
chainring pedaling model, which is to alter the duty cycle from the normal 50%. While this was a
complete independent effort on Jim's part, I'll bet that if he'd been aware of Rotor cranks when
designing his study, he might have simply chosen to use them instead).

Andy Coggan

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

Quoted message said:

Okay, pundits, what's the verdict?

cyclingnews.comtechOpen ↗

--dt

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

Quoted message said:

You decide:

ncbi.nlm.nih.govquery.fcgiOpen ↗ Med&list_ui

Quoted message said:

ds=12165689&dopt=Abstract

(Note that the Rotor cranks do exactly what Jim set out to

accomplish with

Quoted message said:

this one-legged offset chainring pedaling model, which is to

alter the duty

Quoted message said:

cycle from the normal 50%. While this was a complete

independent effort on

Quoted message said:

Jim's part, I'll bet that if he'd been aware of Rotor cranks

when designing

Quoted message said:

his study, he might have simply chosen to use them instead).

Andy Coggan

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

Quoted message said:

Okay, pundits, what's the verdict?

cyclingnews.comtechOpen ↗

See also ncbi.nlm.nih.govquery.fcgiOpen ↗
Med&list_uids=12231284&dopt=Abstract

Article number 12231284 in pub med

Interesting studies. Jobst's ploy of associating these devices with cranks (crackpot variety) is a
weak argument of the fallacy of faulty analogy variety I.e. this is not about getting something for
nothing and the laws of thermodynamics are not being violated.

Phil Holman

In article said:

Doug Taylor said:

Okay, pundits, what's the verdict?

cyclingnews.comtechOpen ↗

To bad these products never show a velocity profile for these solutions to non existent problems.
If they did, you could see that this is nothing more than a complex way of converting the output
of a round chainwheel to that of an elliptical one, using additional levers, bearings, and links.

The claim of inefficiency with conventional cranks assumes that all development of piston engines,
be they steam, diesel or gasoline powered, was amiss and that the correct solution for converting
linear motion to circular motion will be found on bicycles. Investigating the definition of
efficiency makes the concept fall apart because inefficiency means that energy is lost to heat
somewhere in the power cycle. This is not so. Motion over the top and bottom of crank revolution
requires no work and therefore, no power.

Just as with IC engines, all available gas pressure on the piston is expanded and that work
propels the crankshaft, regardless of geometric considerations of leverage and speed during the
cycle. The same is true on a bicycle which approximates the working of a piston engine admirably.
There is no inefficiency in pedaling that can be altered by invoking more muscles or operating at
irregular velocity.

I find amazing how these gimmicks keep arising and how seriously they are taken even though they
are as much like perpetual motion machines as they can get, producing energy where the is none.

Jobst, many IC engines use offset small-end wrist pins to change the power stroke characteristics of
the engines:

fiat-spider.netpiston rodinspectingOpen ↗ .htm

I see where you're going with this, and remain agnostic myself on the merits of rotor cranks,
Biopace, etc. But I think these offset cranks are in use in a good many applications where there is
a desire to make the power and return strokes asymmetrical.

--
Ryan Cousineau, [email hidden] sfu.ca~rcousineOpen ↗ President, Fabrizio Mazzoleni Fan Club

Test them? Why go and do something as silly as actually riding and trying them? Isn't it better to
theorize ad nauseam and create mathematical models to expound the virtues or define the weakness of
a product? C'mon! Lets just postulate, man! You say "test" like this is some kind of riders forum. I
bet you even "tested" pre 2K, Campy ders. with newer Ergo levers. Silly boy, don't you know it
simply won't work?!?!

[email hidden] (Qui si parla Campagnolo) wrote in message
news:<[email hidden]>...

Quoted message said:

taylor-<< Okay, pundits, what's the verdict?

cyclingnews.comtechOpen ↗ >><BR><BR>

we bought a pair to test(60 day money back guarantee)-we'll let ya know-

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 vecchios.comvecchios.comOpen ↗ "Ruote convenzionali costruite eccezionalmente bene"

My own solution is two pedals on each side. You stand on the front ones with both feet,
all the time.
--
Ron Hardin [email hidden]

On the internet, nobody knows you're a jerk.