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PowerCranks - The Discussion

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Mar 12, 2009
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For your situation counterweighted single leg drills would help. The counterweight attached to the opposite crankarm helps mimic the more natural way of pedaling, ie: more force on the down, assisting you through the deadspots. Pretty much the opposite of powercranks. But this is how most people pedal, push down, push down. A similar thing can be done on a fixed gear.

A couple of points.
These are done on a trainer! Not on the road.

Format for drills, try 4 min "on", 6 mins "off", repeat three times. (You can do this on both legs, see what it does for your FTP)

Attaching a counterweight is pretty easy. If you know a machinist then a simple thread to screw into the crank arm, and the other side to fit a standard weight. Alternatively there is a company I think that makes such a thing, based in Melb, Oz, I think.
 
Mar 8, 2009
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Inner Peace said:
Back on topic, and forgetting about Frank's claims of increased power, i'll give you my reasoning for seeking information:

I think this is exactly what you are after.
http://www.luescherteknik.com.au/web_images/Slam flyer pg 1 and 2 web.pdf

From Raoul at http://www.luescherteknik.com.au/

These pedals work really well for working a non injured leg whilst one leg is injured or for overloading a post injury weakened leg..

I hear that there are few guys using them as a serious training means with good effect but that's another debate for another day..:p
 
Jono L. said:
From Raoul at http://www.luescherteknik.com.au/

These pedals work really well for working a non injured leg whilst one leg is injured or for overloading a post injury weakened leg..

I hear that there are few guys using them as a serious training means with good effect but that's another debate for another day..:p
I have a pair of these pedals and the counter weights, although I use them more for power meter calibration than for their intended purpose.

Inertial loaded single leg drills.
 
Jan 30, 2010
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i'm calling them "independent cranks" now - don't want to go down the FDay path....

I've read quite a few of those thread on various forums - very passionate haha

But could we please not go down that track? Discussing the claims of the inventor actually detracts from the thread topic (which is about experience using independent cranks) and goes into territory that has been discussed over and over in many cycling and tri forums...


How about another question, and I really want people to speak from experience if they can, as it would be really really helpful:

independent cranks or a fixed gear bike to train an "even and balanced" pedalling style?

considering that the goal here is to develop an evenly balanced body to reduce the chances of (further) injury

Essentially, both cost the same (if i get a used pair of independent cranks - which someone has offered me), so which is more beneficial for someone with such one-sided injuries and considerable weakness in one leg?

one could argue fixed gear training creates a sloppy pedal stroke if you "let" the pedals guide you, whereas independent cranks 'force' you to apply a evenly distributed power throughout both legs to create a balanced stroke...

anyone got any thoughts based on experience? cheers

and can we call them "independent cranks" from now on to keep the thread on topic? thanks in advance
 
Mar 12, 2009
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Well I have used and been used in an experiment with the single leg counterweighted drills and the result are looking promising for improving performance overall (no great imbalances).

Also at the site posted by Jono there is a an example of these being used in a rehabilitation program, because of a leg injury, for a cyclist with very good results.

This probably (and I do emphasise "probably") is the most effective and cheapest method you could employ.

If you are planning on making a foray to the track however then the track bike will be the best option. The independent cranks suffer the problem of training muscle which do no need to be trained, rehab or not.

Specificity!
 
Jan 30, 2010
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Tapeworm said:
Well I have used and been used in an experiment with the single leg counterweighted drills and the result are looking promising for improving performance overall (no great imbalances).

Tapeworm said:
The independent cranks suffer the problem of training muscle which do no need to be trained, rehab or not.

Now this is why I get confused - you're saying that single leg drills are helpful, yet independent cranks train muscles that don't need to be trained?

my understanding is that independent cranks ARE the equivalent of doing single leg drills - so these two statements get me confused:confused: haha

Regardless, I am doing a lot of single leg drills, but they just don't seem right

I'm thinking a track bike would be a MUCH cheaper way to train a balanced pedal stroke, despite them doing the exact opposite of single leg drills...

i'm sure a combination of everything is probably better than a lot of one thing
 
Mar 12, 2009
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Did you read the study or the post? COUNTERWEIGHTED single leg drills are where it's at. This allows the muscles to fire in same pattern as you when cycling normally. Without the counterweight you may as well get the independant cranks - but the benefits of those are countinuing to be debated.
 
Tapeworm said:
Did you read the study or the post? COUNTERWEIGHTED single leg drills are where it's at. This allows the muscles to fire in same pattern as you when cycling normally. Without the counterweight you may as well get the independant cranks - but the benefits of those are countinuing to be debated.
I think a picture helps. From my ergo bike - SLAM pedals with 11kg counterweight on adjustable length SRM cranks:

IMG_0317.jpg


IMG_0316.jpg
 
Jan 10, 2010
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All very interesting comments. Some valid opinions, some not.

I borrowed a set from a friend a few years ago and will continue to do so as often as I can. (they are expensive)

Basically I use them on the trainer in the winter. For me they are a great help with technique. If you don't have good pedaling technique then they are very hard to use. I have seen very accomplished Cat 1 racers stumble miserably when they thought they could master pedaling powercranks with no practice.

They also are a great tool for building up the muscles that become less developed because of my less than perfect technique in pedaling. Yes I used single leg drills, and still do, but the power cranks don't give you any "mercy". If you don't keep constant, even pressure then you will loose the lock on the crank.

To give you a point of reference, I train 10-12 hrs/week for amateur races, (with power) including both Road and Crits as a Cat 3.
 
Mar 12, 2009
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TexasTom said:
For me they are a great help with technique.

And therein lies the rub. Is technique going to help with power production. So far the answer is no. For aerobic exercise the limiters are still biochemical, and hence training which improves this will improve your power on the bike.
 
It's been fun watching Frank Day squiggle and squirm around this issue on Slowtwitch. He has his heart set on the release of force measuring pedals showing he was right all along. Pity that they have been used in research already and the study (Bohm, 2008) showed a reduction in power. How Frank expects anything different in the field where there is far more to concentrate on than pedalling is quite comical. If the cranks allowed you produce more power then the gap between crank users and non IC cranks users would get larger every year
 
Jan 10, 2010
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Tapeworm said:
And therein lies the rub. Is technique going to help with power production. So far the answer is no. For aerobic exercise the limiters are still biochemical, and hence training which improves this will improve your power on the bike.

You're kidding right!

Everyone knows aerobic limits are biochemical, but that is a different discussion.

Of course better technique increases power and endurance. If it didn't, then you could do just as well with one leg as you do with two. You don't have to read power profiles or the associated studies, or ask all the professional cyclists why they clip in to their pedals. Just try one simple test. Put your bike (with your powermeter) on your trainer and do an hour FTP test on platform pedals with no cleats. Let us know what your comparitive results are!
 
Mar 12, 2009
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TexasTom said:
You're kidding right!
Of course better technique increases power and endurance. If it didn't, then you could do just as well with one leg as you do with two.

You say "of course" but it hasn't actually been proven that if you some how pedal in magical circles that this some how gets around the whole biochemistry thing and you can suddenly find those extra hidden watts. And hence the issues with powercranks, does the body really find more power from "push push push" vs "pedaling in circles."

The two legs vs one is a little off tangent. For a start, there is a reason why the counterweighted leg drills could be a very good thing...

But having two legs on the pedals will be better as it will reduce the amount of lactate being produced (compared to one) and will allow all those nasty metabolites to be cleared more easily.


TexasTom said:
You don't have to read power profiles or the associated studies, or ask all the professional cyclists why they clip in to their pedals. Just try one simple test. Put your bike (with your powermeter) on your trainer and do an hour FTP test on platform pedals with no cleats. Let us know what your comparitive results are!

Already done. Net result for me was no difference (+/- 6 watts in 4 trials, two clipped in, two not, 16km TT). Some in the study resulted a slightly higher average power reading clipped in, some were LOWER, and most like me were unchanged. Not sure if this study was ever published, however it was modeled on one that was done earlier which was. AFAIK they yielded similar results. I will try to locate.

Here's a little reading for you, not the definitive say on everything but raises some very very good points, especially the cycling pattern of elite and amateurs :-

http://www.plan2peak.com/.../32_article_JMartinCrankLengthPedalingTechnique.pdf
 
Sep 13, 2010
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TexasTom said:
You're kidding right!

Everyone knows aerobic limits are biochemical, but that is a different discussion.

Of course better technique increases power and endurance. If it didn't, then you could do just as well with one leg as you do with two. You don't have to read power profiles or the associated studies, or ask all the professional cyclists why they clip in to their pedals. Just try one simple test. Put your bike (with your powermeter) on your trainer and do an hour FTP test on platform pedals with no cleats. Let us know what your comparitive results are!

Betcha it'd be the same with a little practice. But why do that when you can just clip in and push hard? The main reason for clipping is to keep your feet in place.

You know what, you may inadvertently be onto something. It may be a great way to improve technique simply by taping the shoes to the pedals, so as not to be tempted to pull or scrape too hard. Now that may actually improve your technique. You'll learn to use fewer muscles to go just as fast. Sort of an anti-PC exercise. :)
 
kielbasa said:
Betcha it'd be the same with a little practice. But why do that when you can just clip in and push hard? The main reason for clipping is to keep your feet in place.

You know what, you may inadvertently be onto something. It may be a great way to improve technique simply by taping the shoes to the pedals, so as not to be tempted to pull or scrape too hard. Now that may actually improve your technique. You'll learn to use fewer muscles to go just as fast. Sort of an anti-PC exercise. :)

Maybe we should all just be using these: http://powergrips.mrpbike.com/
 
Jan 10, 2010
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Tapeworm said:
You say "of course" but it hasn't actually been proven that if you some how pedal in magical circles that this some how gets around the whole biochemistry thing.......

Oops! That's not what I said. Go back and read my post again.

Tapeworm said:
And hence the issues with powercranks, does the body really find more power from "push push push" vs "pedaling in circles."

The two legs vs one is a little off tangent. For a start, there is a reason why the counterweighted leg drills could be a very good thing...

I was being sarcastic because the powercranks, like your drills, conceptually bring additional muscles in to play (one leg vs two). If you do any sort of high stress work with one set of muscles instead of two, your power and endurance will be less.

Tapeworm said:
Already done. Net result for me was no difference (+/- 6 watts in 4 trials, two clipped in, two not, 16km TT). Some in the study resulted a slightly higher average power reading clipped in, some were LOWER, and most like me were unchanged. Not sure if this study was ever published, however it was modeled on one that was done earlier which was. AFAIK they yielded similar results. I will try to locate.

Here's a little reading for you, not the definitive say on everything but raises some very very good points, especially the cycling pattern of elite and amateurs :-

http://www.plan2peak.com/.../32_article_JMartinCrankLengthPedalingTechnique.pdf

Your link leads to nowhere. Could you repost. I would love to see any study that leads to the conclusion that all the professional riders and their testing is wrong and don't need to clip in.
 
Mar 12, 2009
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TexasTom said:
Oops! That's not what I said. Go back and read my post again.

Pretty sure you said:-

TexasTom said:
You're kidding right!

Everyone knows aerobic limits are biochemical, but that is a different discussion.

Of course better technique increases power and endurance. If it didn't, then you could do just as well with one leg as you do with two. You don't have to read power profiles or the associated studies, or ask all the professional cyclists why they clip in to their pedals. Just try one simple test. Put your bike (with your powermeter) on your trainer and do an hour FTP test on platform pedals with no cleats. Let us know what your comparitive results are!


TexasTom said:
I was being sarcastic because the powercranks, like your drills, conceptually bring additional muscles in to play (one leg vs two). If you do any sort of high stress work with one set of muscles instead of two, your power and endurance will be less.

The theories behind the counterweighted or inertia loaded drills are the fact that they DO NOT bring any additional muscles into play and that the pattern of the muscles firing mimics that of a normal pedalling action. This is a key difference between these drills and the powercranks, and an important one.

The theorised benefit of this is that by focusing effort on one leg at a time for a prescribed time frame is that forces it to undergo the same stimuli as you would for cycling at threshold for one hour - that is an increase in the mitochondria density, neo-vascularisation etc etc. Net result - an improvement in lactate threshold power for a shorter time frame. I do emphasise the theoretical. However as you may have seen there is a company which has developed a tool to perform these drills as they would help to address the issues by the OP, ie: there is more to this than just my opinion.


TexasTom said:
Your link leads to nowhere. Could you repost. I would love to see any study that leads to the conclusion that all the professional riders and their testing is wrong and don't need to clip in.

Which pros and which studies are you referring to?

Try this one. Last third refers to pedalling techniques.
http://www.plan2peak.com/files/32_article_JMartinCrankLengthPedalingTechnique.pdf

I couldn't link directly the studies re: pedalling but will post them separately.
 
Mar 12, 2009
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Mornieux G, Stapelfeldt B, Gollhofer A, & Belli A. (2008). Effects of pedal type and pull-up action during cycling. International Journal of Sports Medicine. 29(10), 817-22.

And abstract:
“The aim of this study was to determine the influence of different shoe-pedal interfaces and of an active pulling-up action during the upstroke phase on the pedalling technique. Eight elite cyclists (C) and seven non-cyclists (NC) performed three different bouts at 90 rev . min (-1) and 60 % of their maximal aerobic power. They pedalled with single pedals (PED), with clipless pedals (CLIP) and with a pedal force feedback (CLIPFBACK) where subjects were asked to pull up on the pedal during the upstroke. There was no significant difference for pedalling effectiveness, net mechanical efficiency (NE) and muscular activity between PED and CLIP. When compared to CLIP, CLIPFBACK resulted in a significant increase in pedalling effectiveness during upstroke (86 % for C and 57 % NC, respectively), as well as higher biceps femoris and tibialis anterior muscle activity (p < 0.001). However, NE was significantly reduced (p < 0.008) with 9 % and 3.3 % reduction for C and NC, respectively. Consequently, shoe-pedal interface (PED vs. CLIP) did not significantly influence cycling technique during submaximal exercise. However, an active pulling-up action on the pedal during upstroke increased the pedalling effectiveness, while reducing net mechanical efficiency.”
 
Mar 12, 2009
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And to be fair there is this one, though I think their protocol was a little off, and makes no comparison of power outputs. Also the abstract at least doesn't quantify HOW much more the oxygen consumptions is etc.



The Effect Of Different Pedal Types On Maximal Oxygen Consumption And Lactic Acid Accumulation.
Abstract
Journal of Strength & Conditioning Research. 24 Supplement 1:1, January 2010.
Hiebert, Jean M; Hoover, Don L; Best, Michael A; Black, Ashlie B; Hruska, Ryan K; Jones, Mariah E

Abstract:
Cycling efficiency is dependent upon many factors such as bike set up, body position, and pedaling cadence. These and other factors often have a large influence on both performance and risk of injury. One parameter not fully understood is the influence of available pedal systems on cycling efficiency, and little scientific literature exists on this topic. To determine the effect of different pedal systems on maximal oxygen consumption ([latin capital V with dot above]o2max) and lactic acid production during direct testing of maximal aerobic power. Nine healthy recreational cyclists (7 males and 2 females; 36.11 +/- 7.7 years) volunteered to participate in the study. On average, subjects cycled 3-4 times per week for 1-2 hours at a moderate to high intensity. Subjects performed a maximal bicycle graded exercise test on their own bicycle, using one of three pedal systems on different occasions. Pedal systems included: 1) flat pedals, 2) toe-clip pedals, and 3) clipless pedals, and the order of the pedal systems was randomized. Riding resistance was provided by a computer controlled bicycle ergometer and trainer. Initial resistance was based on a 1:1 power (watts) to individual body weight (kg) ratio and increased 2:1, 3:1, etc. every two minutes until subjects were unable to maintain a pedal cadence of at least 50 revolutions per minute. Gas exchange was analyzed using a portable metabolic system. A portable lactate analyzer was used to measure lactic acid levels prior to the test, upon completion of the test, and at 3, 5 and 7 minutes post-test or until values returned to baseline. A one-way ANOVA with repeated measures was conducted to evaluate the relationship between pedal type and the dependent variables, oxygen consumption and lactic acid production. While there were differences in performance under the three pedal conditions, these differences were not statistically significant for either the oxygen consumption or the lactic acid production. Participants produced higher average [latin capital V with dot above]o2 values during the clipless condition. Lactic acid accumulation was highest in the flat pedal condition. Lastly, when using the clipless pedals, participants achieved peak lactic acid levels at relatively higher oxygen consumption measures when compared to the flat pedal or toe-clip pedal conditions. Pedal condition did not produce statistically significant differences in maximal oxygen consumption or in lactic acid during a graded exercise test. However, these findings may be clinically meaningful, as statistically significant difference often may not exist within a given group of cyclists, whether the group be performing at a local amateur cycling event or an event such as the Tour de France. Participants produced higher average O2 max values during the clipless condition, suggesting this condition may be more efficient as is commonly believed. Lactic acid accumulation was highest in the flat condition, suggesting participants may have been least efficient when pedaling in this condition. Likewise, the achievement of peak lactic acid levels at relatively higher oxygen consumption further suggests the clipless pedals promote higher performance levels when compared to the flat and toe-clip conditions. Our findings suggesting clipless pedals allow for greater efficiency and result in higher performance. Further study is necessary to investigate these potentially clinically meaningful findings.
 
Jan 10, 2010
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I now see where our disconnect in this discussion exists. I'm considering this topic from a purely physics perspective relative to the forces applied to the pedals. I'm not looking at this from the biomechanical aspect which is the primary influence on performance.

I see they do come to the conclusion that clipless pedals do improve performance, but that it may not be tied to pedaling techique is very hard to accept.

Okay, since you're so willing, help me with this......

Let's say each of my legs weighs "X".

And I'm pushing down with the force of "Y" to propel the bike.

If I rest my leg on the pedal on the upstroke then the force that I have to apply on the downstroke to maintain a constant speed is "X" + "Y".

But if I have good enough technique to at least "unweight" my leg on the upstroke, then the downward force required to maintain the same speed as above is only "X".

So from a pure analysis of force it is clear which is the most efficient.

Now I understand this is oversimplification, but is the suggestion that the process of unweighting (or pulling up and through on the top and the bottom for perfect techique) results in a sufficient amount of a detrimental biomechanical impact so as to offset the physics of even pedal forces?
 

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