A Cycling & bikes forum. CycleBanter.com

Go Back   Home » CycleBanter.com forum » rec.bicycles » Techniques
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

PowerCranks Study



 
 
Thread Tools Display Modes
  #11  
Old October 5th 03, 05:33 PM
Phil Holman
external usenet poster
 
Posts: n/a
Default PowerCranks Study


wrote in message
...
Phil Holman writes:

This sounds more like a book promotion than a report on the cranks.
Barkers at circus sideshows show more than this lead-on. How can
you repeat such jive? By the way, remind me of the principal
behind PC's. Are these the cranks that do not come around by
themselves and require pulling up to make them remain synchronous
(180 degrees apart)?


Yes, that's correct Jobst. Reading between the lines of the
newsletter, it looks like the study will reveal that training with
the cranks will increase power output by 'x' amount. This might be

a
little more newsworthy than the umpteenth thread on shimmy but
that's just my opinion. We'll just have to wait and see.


There is no doubt that adding the effect of lifting (actually pulling
back, lifting and pushing forward over the top will impart more power
to cranks, however, it will not produce more power from the rider for
a given aerobic level.


We've gone over this before. The athletes who typically display the
highest V02 max are those who utilize the most muscle mass (e.g.
X-Country Skiers).

Quite to the contrary. Engaging more muscles
in propelling the bicycle burdens the heart and lungs with the
overhead of more muscles rather than using the principal ones that are
naturally used. If this were not so, foot plus hand cranks would
produce a greater speed in TT's, flat and hill climbs, but they don't.


It is my understanding that the lungs are not the constraint given their
overcapacity in normal athletes. If they were, we would see venous blood
desaturation in all athletes at and above their aerobic limit. The
constraint is not just pumping capacity of the heart either. There is
separation in performance between athletes with identical cardiac
output. There are plenty of sports physiology references out there
raining knowledge soup. Wearing one's soup bowl as a rain bonnet will do
nothing but perpetuate an empty place holder for knowledge.
As for hand and foot cranking, I've seen a number of these devices and
it's probably the design constraints and unwieldy operation of such
contraptions outweighing any power gains. I've also seen studies
demonstrating the opposite for durations exceeding just anaerobic
considerations.


Anyone who has not trained with these cranks cannot ride with them,
the requirement to keep positive forward torque on both cranks
throughout rotation is difficult to accomplish. I'm sure that Lance
Armstrong could not ride rollers with these at the bicycle show,
something no bicycle racer I saw at InterBike 2002 do. If these
cranks did what they claim to do, we wouldn't see riders dominate
in races against PowerCrank devotees.


I gained 1 mph in TT speed. This will not necessarily make one a winner
of anything.
The highest ranked cyclist using them is Paolo Bettini - UCI ranked 3rd
in Jan 2003.


Let's not overlook that with conventional cranks, the feet an legs are
balanced and that it take no effort to rotate the cranks forward,
clipped in and with non chain. With Power Cranks, this takes
considerable effort, the feet not balancing each other.
The limit of climbing hills or flat TT depends on aerobic capacity.
That is what good bicycle racers have that others don't.


I totally agree and the limiting factor in aerobic capacity is the
ability of the muscles to utilize oxygen. The report should reveal what
aerobic gains were made.

Phil Holman



Ads
  #14  
Old October 5th 03, 06:56 PM
Per Elmsäter
external usenet poster
 
Posts: n/a
Default PowerCranks Study

n crowley wrote:

No but I have an interesting pedaling technique which almost reverses
the rowing technique, instead of the arms applying the power to the
oars, the feet apply the power to the pedals while making maximum use
of arm pulling up power to increase that pedal power whenever the
necessity for this extra power arises.


That just sounds like normal climbing techniques. Nothing that can be
sustained over a longer period of time.

--
Perre

You have to be smarter than a robot to reply.


  #15  
Old October 5th 03, 07:27 PM
n crowley
external usenet poster
 
Posts: n/a
Default PowerCranks Study

Originally posted by Per ElmsäTer n crowley wrote:

No but I have an interesting pedaling technique which almost reverses
the rowing technique, instead of the arms applying the power to the
oars, the feet apply the power to the pedals while making maximum use
of arm pulling up power to increase that pedal power whenever the
necessity for this extra power arises.


That just sounds like normal climbing techniques. Nothing that can be
sustained over a longer period of time.
==============================================



Try using the normal climbing technique when riding a track pursuit at
maximum power application and in an aerodynamic position.



--
--------------------------

Posted via cyclingforums.com
http://www.cyclingforums.com
  #16  
Old October 5th 03, 07:55 PM
Per Elmsäter
external usenet poster
 
Posts: n/a
Default PowerCranks Study

n crowley wrote:
Originally posted by Per ElmsäTer n crowley wrote:

No but I have an interesting pedaling technique which almost reverses
the rowing technique, instead of the arms applying the power to the
oars, the feet apply the power to the pedals while making maximum use
of arm pulling up power to increase that pedal power whenever the
necessity for this extra power arises.


That just sounds like normal climbing techniques. Nothing that can be
sustained over a longer period of time.
==============================================



Try using the normal climbing technique when riding a track pursuit at
maximum power application and in an aerodynamic position.


Well that makes it more like a sprint position. Neither a sprint nor a track
pursuit can be sustained over a longer period of time.
So tell us instead how you accomplish this.

--
Perre

You have to be smarter than a robot to reply.


  #17  
Old October 5th 03, 07:59 PM
external usenet poster
 
Posts: n/a
Default PowerCranks Study

N? Crowley writes:

There is no doubt that adding the effect of lifting (actually
pulling back, lifting and pushing forward over the top will impart
more power to cranks, however, it will not produce more power from
the rider for a given aerobic level. Quite to the contrary.
Engaging more muscles in propelling the bicycle burdens the heart
and lungs with the overhead of more muscles rather than using the
principal ones that are naturally used. If this were not so, foot
plus hand cranks would produce a greater speed in TT's, flat and
hill climbs, but they don't.


Rowers combine arm and leg power to improve performance and it does
not burden their heart and lungs.


I think you'll find that rowers row with their legs, their hands and
arms functioning much like the foot and ankle of the bicyclist at the
ends of a pedal strokes where inconsequential power is transmitted.

If cyclists had the correct linear pedaling technique, they too
could combine the pushing and pulling on fixed normal bars for
additional pedal power without overloading their heart and lungs.


The concept of linear pedal mechanisms and the like is a discredited
belief of people who do not recognize reality. Bicycle riding has
been scrutinized for more than a century and nothing new and useful
has come up since the beginning of the chain driven bicycle.

The most efficient pedaling is the technique that enables you to
apply very effective power to the pedal from 11 to 5 'clock
regardless of what your cadence is because this enables you to use a
higher gear for the same effort of a rider who does not have this
technique. The pulling up is done by the arm not the leg.


I think you are mistaken. Go row a bit and observe what occurs. The
bicyclist ha no lack of transmitting power but rather a limited
aerobic capacity, and nothing will get past that. you seem to believe
that power can be extracted from muscles without them demanding oxygen
and glycogen. I think you ignore that the first measurement of
interest by a bicycling team is lung capacity, not muscles or pedaling
style.

The explanation for the ineffectiveness of PowerCranks is that the
pulling power of the leg is only effecive at a low cadence or when
out of the saddle and even then can only be used for short periods.


Not at all. The problem is that lifting the leg against gravity is
work even without adding any torque. On normal cranks the legs are
balanced and require no effort to go around, up or down.

Let's not overlook that with conventional cranks, the feet an legs
are balanced and that it take no effort to rotate the cranks
forward, clipped in and with non chain. With Power Cranks, this
takes considerable effort, the feet not balancing each other.


If you were pedaling for most benefit, the feet would not be
balanced as you should be unweighting the idling pedal as soon as
you stop applying the power, making the most out of the assistance
of gravity. In that one instance PowerCranks could prove to you the
error of your ways.


Why "should" I be unweighting the "idling" pedal? That makes
unnecessary work that I can do without. This work is better done with
the descending leg. Invoking other muscles to do this is inefficient.
That the downward pushing muscles have the ability to do this is amply
demonstrated and that there is reserve is demonstrated in sprints that
use up the aerobic capacity. You are suggesting that there is an
inefficiency in the principal muscles we use to propel ourselves and
engaging other unnatural muscles improves power generation. I don't
believe a word of it.

The limit of climbing hills or flat TT depends on aerobic
capacity. That is what good bicycle racers have that others don't.


True but knowing how to get the most out of your pedals and cranks
can help you to make the most of your aerobic capacity.


You think you can fool the muscles into doing free work.

Jobst Brandt

  #18  
Old October 5th 03, 08:03 PM
external usenet poster
 
Posts: n/a
Default PowerCranks Study

Pete Cresswell writes:

Engaging more muscles in propelling the bicycle burdens the heart
and lungs with the overhead of more muscles rather than using the
principal ones that are naturally used.


Does that supply me with a rationale to not learn how to spin?


You don't need to do anything but push down on pedals to spin.
Fortunately, rigidly connected cranks constrain the feet to move in
circles and do so in a balanced manner. All the ride needs to do is
inject some energy into that rotation at a suitable rate. Let's not
get pedaling rate confused with "round pedaling", a subject similar to
the study of ankling of the past.

Jobst Brandt

  #19  
Old October 5th 03, 08:16 PM
external usenet poster
 
Posts: n/a
Default PowerCranks Study

N? Crowley writes:

No but I have an interesting pedaling technique which almost
reverses the rowing technique, instead of the arms applying the
power to the oars, the feet apply the power to the pedals while
making maximum use of arm pulling up power to increase that pedal
power whenever the necessity for this extra power arises.


That's interesting. Well trained bicycle racers do not pull up on the
bars at all. The bars are used in sprinting or steep climbing while
standing in order to counter the torque of pulling up on the rear
pedal. This is done by pushing down with one hand and pulling up with
the other, the push being grater than the pull. If this were not down
the rider would fall off the bicycle. This is not work because the
arms do not articulate while providing this counter force. However,
for the longer term, a gear is selected that does not require pulling
up on pedals. That's the reason for gears.

I think you should ride some more and observe what occurs.

Jobst Brandt

  #20  
Old October 5th 03, 08:40 PM
Werehatrack
external usenet poster
 
Posts: n/a
Default PowerCranks Study

On Sat, 04 Oct 2003 06:57:45 GMT, "Phil Holman"
may have said:

Reading between the lines of the newsletter,
it looks like the study will reveal that training with the cranks will
increase power output by 'x' amount.


Any bets that the gadget merely achieves what can be had by a
clipless-pedal user (or toeclip user, for that matter) with proper
training *without* the freewheeling crank and its attendant
disadvantages?

I have little doubt that high-level professional racers already employ
the technique that this gadget's makers claim can only be learned
through the use of their device. They seem to think there's magic in
their alleged "positive feedback", but what I see is *negative*
feedback for a non-pull return stroke, and I'm sure there are ways to
learn to pull without their widgetry.

--
My email address is antispammed;
pull WEEDS if replying via e-mail.
Yes, I have a killfile. If I don't respond to something,
it's also possible that I'm busy.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Science Proves Mountain Biking Is More Harmful Than Hiking Stephen Baker Mountain Biking 18 July 16th 04 04:28 AM
Powercranks Study Published Phil Holman Racing 0 December 28th 03 06:12 PM
Data (was PowerCranks Study) Phil Holman Racing 102 October 21st 03 12:21 AM
Reports from Sweden Garry Jones Social Issues 14 October 14th 03 05:23 PM
PowerCranks Study Phil Holman Racing 3 October 4th 03 07:54 AM


All times are GMT +1. The time now is 10:45 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 CycleBanter.com.
The comments are property of their posters.