Weird independent cranks

Zog The Undeniable said:

Anyone seen these before? Do they work?

You had to ask. Read about them below. And read, and read...

tinyurl.com2clwfOpen ↗

Do they work? Apparently, with great effort and practice,
you can make the bike go forward with them.
--
terry morse Palo Alto, CA bike.terrymorse.combike.terrymorse.comOpen ↗

On Sat, 06 Mar 2004 14:41:37 +0000, Zog The Undeniable

may have said:

A guy in the local road club is currently riding with a
rather wide and ugly set of gold-anodized cranks which have
some kind of ratchet mechanism in them so they transmit
drive, but rotate independently of each other. The idea is
that the crank being pushed down doesn't help to pull the
opposite one up, so the rider has to learn to pedal in
circles. An odd effect is that the cranks rest "in phase"
when the bike is parked!

Anyone seen these before? Do they work?

Probably a set of the too-often-discussed and most often
disparaged Powercranks.

powercranks.compowercranks.comOpen ↗

This has been debated too often before; Google will supply
plenty of reading material.

I will limit my comments to these:

The technique "taught" by the device can be learned without
the need for the device. Despite this, the technique is far
from universally encouraged.

The device makes ordinary use of the bike unnecessarily
unpleasant.

The limitations on human power generation are due to
cardiovascular capacity issues and not muscle mass or
duration of muscular application. This is the basis of
respected theoretical grounds for holding that the technique
taught by the device is worthless for the competitive
athlete whose power generation capacity is at or near the
maximum possible. Since the point of the device is purported
to be performance gain in any event, and since the sub-
maximal athlete can achieve gains by normal means, the
device is of questionable utility there as well.

The device is heavy and expensive.

Claims are made for performance gains in the absence of any
data proving that the gains accomplished are due to the
device and technique, and are not merely attributable to
increased attention to exercise in the subject.

I would point out that while they claim that patents have
been granted, I could find no patent numbers listed on their
website, and while an exhaustive search might still turn up
their filing, I was unable to loacte a patent that seemed to
apply to their device. The trademark for the device dates
back only to November 2002, so the claims for continuing
gains in the second year of training seem to be somewhat
peculiar as well.

My opinion: like many things that have been marketed with
claims that are "too good to be true", the Powercranks make
many more statements of efficacy than can be reasonably
accepted. I will continue to regard them as more marketing
than product.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Zog The Undeniable said:

A guy in the local road club is currently riding with a
rather wide and ugly set of gold-anodized cranks which
have some kind of ratchet mechanism in them so they
transmit drive, but rotate independently of each other.
The idea is that the crank being pushed down doesn't help
to pull the opposite one up, so the rider has to learn to
pedal in circles. An odd effect is that the cranks rest
"in phase" when the bike is parked!

Anyone seen these before? Do they work?

And we on rec.bicycles.tech were all just celebrating that
the PowerCranks thread had finally died. 🙁

Tom Sherman - Quad Cities (Illinois Side)

Terry Morse said:

Do they work? Apparently, with great effort and practice,
you can make the bike go forward with them.

Is that what Powercranks are? I always assumed they were
some kind of power-measuring device like a Powertap!

Zog The Undeniable <[email hidden]> wrote in message news:<404a3db3.0@entanet>...

Quoted message said:

Terry Morse said:

Do they work? Apparently, with great effort and
practice, you can make the bike go forward with them.

Is that what Powercranks are? I always assumed they were
some kind of power-measuring device like a Powertap!

Dear Zog,

To be fair, Phil Holman has been trying these odd
contraptions as a training experiment and has been
surprised by the improvement in his times. He's still
looking into them.

I gather that the theory is that because the cranks are
independent, you're forced to learn to raise both your legs
equally in a fashion that's supposed to be somehow more
efficient or powerful.

The idea is very faintly like using a pair of dumbbells to
work each arm instead of a single bar with weights on both
ends, but it's a training scheme, not a mechanical
advantage.

The idea is also, as you must have already gathered, viewed
with scorn and alarm by many posters, whose theories
demolish the whole notion. If more riders try the things and
find themselves going faster, then the theories will have to
be reconsidered.

Unfortunately, the effect is small, if it exists, so
demonstrating it will be difficult, but this is probably
true of all the undiscovered tricks that remain in the
bicycling world.

I'm damned if I can see how to separate the claimed effect
from the kind of improvement that we should expect from any
new training scheme that involves paying more attention to
pedalling and a few months of hard, motivated work.

Me, I don't even use cleats.

Carl Fogel

Quoted post said:

Originally posted by Tom Sherman

BZog The Undeniable said:

A guy in the local road club is currently riding with a
rather wide and ugly set of gold-anodized cranks which
have some kind of ratchet mechanism in them so they
transmit drive, but rotate independently of each other.
The idea is that the crank being pushed down doesn't help
to pull the opposite one up, so the rider has to learn to
pedal in circles. An odd effect is that the cranks rest
"in phase" when the bike is parked!

Anyone seen these before? Do they work?

And we on rec.bicycles.tech were all just celebrating that
the PowerCranks thread had finally died. 🙁

Tom Sherman - Quad Cities (Illinois Side) [/B]

Some of us aren't celecbrating yet since it hasn't surpassed the helmet thread.🙁

Carl Fogel said:

Me, I don't even use cleats.

I don't even use pedals. I ride barefooted and grip the ends
of the cranks with my toes, like a monkey.

Zog The Undeniable said:

Carl Fogel said:

Me, I don't even use cleats.

I don't even use pedals. I ride barefooted and grip the
ends of the cranks with my toes, like a monkey.

What are cranks?

--
F. Flintstone

Quoted post said:

Originally posted by Werehatrack

I would point out that while they claim that patents have
been granted, I could find no patent numbers listed on their
website, and while an exhaustive search might still turn up
their filing, I was unable to loacte a patent that seemed to
apply to their device.

I just looked at the patent and implementation is constructed with two freewheeling clutches, each clutch site on each crank arm. (I previously assumed it was constructed using a planetary gear construction with chainring on ring gear (no pun intended), and the cranks arms on each of the sun and planet gear)

An unclaimed but disclosed embodiment showed the implementation with a pair of generators on each crank driving a motor.

Here is the data on the patent family:

INVENTOR: DAY, F J

PATENT-ASSIGNEE: DAY F J[DAYFI]

PRIORITY-DATA: 1997US-0819165 (March 17, 1997)

Patent numbers and issue dates:

WO 9841441 A1 September 24, 1998 023
AU 747397 B May 16, 2002
AU 9864666 A October 12, 1998
US 5860329 A January 19, 1999
EP 968115 A1 January 5, 2000
JP 2000510562 W August 15, 2000

US classification: 074/594.100
International classification assigned by US
Patent Office: B62M 001/02
International classification assigned by Japanese Patent Office: 028 F16C 003/06

My Derwent database is usually 3-4 months old, but this is probably complete. Another database that shows some smaller country patents is down at this moment.

The assignee paid the June 2002 maintenance fee in February 2002.

Here is a link to the US patent:
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=5860329.WKU.&OS=PN/5860329&RS=PN/5860329

The US Patent identifies the inventor as Franklin J. Day rather than by initials per the above Derwent database.

-a patent attorney

Tim McNamara said:

What are cranks?

Certain people who post regularly to rec.bicycles.tech. 😉

Tom Sherman - Quad Cities (Illinois Side)

On 6 Mar 2004 18:56:47 -0800, [email hidden] (Carl Fogel) may

have said:

I'm damned if I can see how to separate the claimed effect
from the kind of improvement that we should expect from any
new training scheme that involves paying more attention to
pedalling and a few months of hard, motivated work.

Personally, I think you just drove that nail all the way
through the stud and into the next wall.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

On Sun, 07 Mar 2004 20:16:41 -0600, Tom Sherman

may have said:

Tim McNamara said:

What are cranks?

Certain people who post regularly to rec.bicycles.tech. 😉

And the ones who are most insistent about their positions
are the powercranks?

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Werehatrack said:

On Sun, 07 Mar 2004 20:16:41 -0600, Tom Sherman

may have said:

Tim McNamara said:

What are cranks?

Certain people who post regularly to rec.bicycles.tech. 😉

And the ones who are most insistent about their positions
are the powercranks?

Correct.

Tom Sherman - Quad Cities (Illinois Side)