Powercranks

Hjalmar Duklæt wrote:
Well, this is probably true for maximum effort but I would believe that
using extra muscle groups to do the work would be benefitial when it comes
to endurance and submaximal efforts. It would take longer before the mucles
were exhausted.

If you cycle regularly muscles do not become exhausted provided you keep
them fuelled. You may be stiff the next day but that is another matter.
--
David Damerell Kill the tomato!

Hjalmar DuklæT wrote:
wrote in message news:NdmTb.12155-
$XF6. -
nic.net...
Bill who? writes:

Hi. I'm new the the group but thought this would be the right place
to ask. Just got a set of Powercranks and put them on the bike I've
been using on my Computrainer. Gee, I used to enjoy my
Computrainer! Now I can only ride it for about 3 miles! Anyone else
had experience with Powercranks? Does this get better or is this
why I see them on e-bay so often?

Here is some interesting feedback:

http://www.pezcyclingnews.com/?pg=fu...//www.pezcycl-
ingnews.com/?pg=fullstory&id=1882

The author, Josh Horowitz, should be comming upon his one month
update shortly.

That makes painful reading for me, having ridden Power Cranks on a
demo just long enough to understand what the concept is. No doubt it
is exhausting and it builds new muscles to do a task that ordinary
cranks make unnecessary. The easiest way to return the foot/pedal/leg
from the bottom of the stroke to the next power stroke is to let it
ride. That is, unless you don;t have two reasonably equal legs that
are balanced when you sit on the bicycle without a chain.

If you see two riders, one with weight lifter muscles and a slim, no
fat rider with big lungs, I believe that most riders will recognize
the bikie as the slender guy. That's because only for sprints are big
extra muscles useful. The limit of most fit bicyclists is not muscles
but cardiovascular. More muscles and using otherwise unused muscles in
propulsion is someone's dream of a speed secret.

This goes in the same bucket as round pedaling and ankling.

This sounds so much like patent medicine with no supporting evidence:

http://www.powercranks.com/http://www.powercranks.com/

Jobst Brandt
Well, this is probably true for maximum effort but I would believe that
using extra muscle groups to do the work would be benefitial when it
comes to endurance and submaximal efforts. It would take longer before
the mucles were exhausted. During a 5 hours road race I guess this is
what counts, not your cardiovascular maximum limit.Or am I completely
wrong here? Hjalmar


I have been using them for about 8 weeks now and training 3 sessions
week for about an hour on them. I can now ride up to 3 hours without
real problem but at lower cadences than I would normally be at. I ca
detect an improvement in my riding in terms of strength (no I canno
back this up except that my best race results have fallen in this time)
No doubt Ric Stern will tell you that it has not been shown that
rounder stroke is necessarily better, but I believe that it could b
more efficient to spread the work load among different muscles

It certainly gets easier fairly quickly so worth persevering

Pete


-

"Hjalmar Duklæt" writes:

wrote in message
...

If you see two riders, one with weight lifter muscles and a slim,
no fat rider with big lungs, I believe that most riders will
recognize the bikie as the slender guy. That's because only for
sprints are big extra muscles useful. The limit of most fit
bicyclists is not muscles but cardiovascular. More muscles and
using otherwise unused muscles in propulsion is someone's dream of
a speed secret.

Well, this is probably true for maximum effort but I would believe
that using extra muscle groups to do the work would be benefitial
when it comes to endurance and submaximal efforts. It would take
longer before the mucles were exhausted. During a 5 hours road race
I guess this is what counts, not your cardiovascular maximum
limit.Or am I completely wrong here?

For long events, the limits are very much cardiovascular. Weight is
weight, whether it's fat, muscle or bike, and it takes more work to
haul weight uphill. In any sort of race with any significant
climbing, the lighter rider is at an advantage and it doesn't matter
if it's fat or muscle.

When I was doing randonees this summer, I noticed that the scrawny
un-muscular guys tended to be the fastest over 200, 300, 400, 600 and
1200 kilometers. At 6'3" (sheesh, I shrank an inch over the last 10
years) and 210 lbs, I found that I was at a bit of a disadvantage over
the long haul. Look at the 1996 Tour winner, Bjarne Riis. He had
skeletal legs, practically no muscle at all and practically no body
fat (IIRC he was at about 4% body fat).

My thighs are bigger than Armstrong's and I suspect I can lift more
weight in a squat, but he's able to climb l'Alpe-d'Huez literally
twice as fast as I can. He weighs 60 lbs less and has cardiovascular
capacity and a VO2 max I can only dream about.

On the flat, where wind resistance is the primary issue, the larger
more muscular rider tends to have an advantage. Compare the TT
prowess of Miguel Indurain and Marco Pantani for an example.

Tim McNamara wrote:

On the flat, where wind resistance is the primary issue, the larger
more muscular rider tends to have an advantage. Compare the TT
prowess of Miguel Indurain and Marco Pantani for an example.

Even in a flat TT comparison, it's not Indurain's muscle mass that
makes him faster than Pantani. Indurain simply has a bigger
cardiovascular engine. Pantani's power-to-weight ratio is higher,
even though his max. power output is lower.
--
terry morse Palo Alto, CA http://www.terrymorse.com/bike/

finally a scientific response.

--
--------------------------
Andre Charlebois
BPE, MCSE4.0, CNA, A+
webmaster for Triathlon New Brunswick
www.TriNB.com
"Carl Fogel" wrote in message
om...
"Bill" wrote in message
...
wrote in message
...
Hi. I'm new the the group but thought this would be the right place to
ask. Just got a set of Powercranks and put them on the bike I've been
using on my Computrainer. Gee, I used to enjoy my Computrainer! Now I
can only ride it for about 3 miles! Anyone else had experience with
Powercranks? Does this get better or is this why I see them on e-bay
so often? Thanks in advance!

JohnT.

Here is some interesting feedback:
http://www.pezcyclingnews.com/?pg=fullstory&id=1882
The author, Josh Horowitz, should be comming upon his one month update
shortly.
Bill

Dear John and Bill,

In the article that Bill mentions, the rider makes
the same complaint as John--using the Powercranks
leaves him sore as hell and feels quite awkward,
at least at first. He couldn't ride very long with
them for more than a week.

If he's sore because he's using different muscles,
then he may get used to it. But if cardiovascular
capacity is what really matters in bicycling for hours,
then using more or different muscles is unlikely to
help him rider faster.

If there were any mechanical advantage, then it
would show up immediately.

If it trains him to change the way that he pedals
in some more efficient way, then he should be able
to return to a normal crank, pedal in his new style,
and achieve the same results. (Or better, since a
normal crank of the same strength is lighter.)

If it's a Hawthorne-style placebo effect (initial
improvement caused by being observed), then it
will join many other contraptions that motivated
people to work harder and then credit the contraptions
with the results of their extra effort.

Carl Fogel

Carl Fogel wrote:

If it trains him to change the way that he pedals
in some more efficient way, then he should be able
to return to a normal crank, pedal in his new style,
and achieve the same results. (Or better, since a
normal crank of the same strength is lighter.)

Powercranks are intended to as a training device, not as a permanent
replacement for conventional cranks. The idea is exactly as you say: to
change the way that someone pedals so that when he returns to normal
cranks he will achieve better results. It's sort of like those ankle
weights that basketball players use in practice -- they don't wear them in
the actual game.

I do not know if the results match the theory.

Terry Morse wrote:
Tim McNamara wrote:

On the flat, where wind resistance is the primary issue, the larger
more muscular rider tends to have an advantage. Compare the TT
prowess of Miguel Indurain and Marco Pantani for an example.

Even in a flat TT comparison, it's not Indurain's muscle mass that
makes him faster than Pantani. Indurain simply has a bigger
cardiovascular engine. Pantani's power-to-weight ratio is higher,
even though his max. power output is lower.

Even though Indurain had lower power-to-weight than Pantani, across
individuals CdA scales less than linearly with mass -- in the ballpark of
perhaps the cube root or so. Besides, Pantani's ears stuck out.

The verdict of the experts is in: sub-sprint-intensity cycling
performance is completely determined by cardiovascular capacity and
wind resistance, with weight also playing a role only on steep climbs.
Having thought this through to its logical conclusion, I hereby offer
three suggestions that I believe will revolutionize cycling as we know
it:

1. Lower your seat and handlebars by six inches; you'll probably have
to purchase a smaller frame, but it will be worth it. Sitting high
enough to straighten the legs to within 30 degrees or so of full
extension is a waste. People do it in the name of "efficiency" or
"muscular endurance" or some such pseudo-science, but obviously if you
sit six inches lower you'll still have the same cardiovascular
capacity, hence the same power. Your wind resistance will be
considerably less due to your lower profile, so you'll go faster.

2. The appropriate innovation in cranks is not PowerCranks but
ShortCranks -- the shorter the better, but something in the
neighborhood of 60 mm should suffice. Any machine shop should be able
to make this modification to your existing cranks, as long as they're
not carbon. This will further stabilize and reduce your aerodynamic
profile, and again your cardiovascular system will produce as many
watts as ever. The result, of course, is that you'll go faster still.
As an additional benefit, bicycles fitted with ShortCranks can have
lower bottom brackets, allowing you to sit closer to the ground and
achieve even less wind resistance; frame builders, however, will need
some time to catch up to this innovation.

3. Get rid of all those unnecessary gears. You've got just as much
cardiovascular capacity pedaling at 30 rpm or 150 rpm as you do in the
so-called "recommended range" of 90 to 110 rpm, so one gear is all
anyone needs. Because of all the wind resistance saved by the
preceding recommendations, you'll be going much faster than usual, so
you should choose the largest possible combination (53x11, or higher
if you can find the components) for your one gear. The combination of
reduced weight and improved aerodynamics (the latter cannot be ignored
even at climbing speeds) will have you ascending faster than ever!
Abandon those old wives' tales about "strength" and go climb your
local benchmark - be it Page Mill, Mt. Washington, or Mont Ventoux -
in a 53x11, with 60 mm cranks, sitting six inches lower than you're
sitting today. It'll be like nothing you've known before.

Terry Morse writes:

Tim McNamara wrote:

On the flat, where wind resistance is the primary issue, the larger
more muscular rider tends to have an advantage. Compare the TT
prowess of Miguel Indurain and Marco Pantani for an example.

Even in a flat TT comparison, it's not Indurain's muscle mass that
makes him faster than Pantani. Indurain simply has a bigger
cardiovascular engine. Pantani's power-to-weight ratio is higher,
even though his max. power output is lower.

You also have to factor in aerodynamics; the two are not going to be
that much different but Indurain has more power available by having
much more muscle mass. So while Pantani's power-to-weight ratio is
better, Indurain's "power-to-drag" ratio is superior. The math has
been published on this, jeez, years ago.

"Andre" writes:

finally a scientific response.

Carl Fogel:

If it's a Hawthorne-style placebo effect (initial improvement
caused by being observed), then it will join many other
contraptions that motivated people to work harder and then credit
the contraptions with the results of their extra effort.

The Hawthorne effect is an interesting notion in this regard, although
it's not a placebo effect per se. There are similarities in the two
concepts that make them easy to confuse.

Here's some information on the Hawthorne effect for the bored:
http://www.psy.gla.ac.uk/~steve/hawth.html