The importance of crank length to the cyclist.

[Martin318is]

Which is why you shouldn't be participating in these threads devoted to some of these anecdotes. Further, if your understanding of the science can't explain all of the observations being made then you shouldn't be here pretending that your understanding is complete and coming here criticizing those of us trying to discuss some of these more "off the wall" things.

Strange logic there. If a group of people are discussing a topic that is new to them and their understanding of the topic is lacking information that you have, wouldn't you consider it helpful to provide that information?

The alternative - that you appear to be arguing - is that only unproven theories can be discussed in this thread and that anyone with real knowledge on the topic should stay away...

 

[FrankDay]

Strange logic there. If a group of people are discussing a topic that is new to them and their understanding of the topic is lacking information that you have, wouldn't you consider it helpful to provide that information?

Ah yes, if only that would happen, someone with the knowledge of Dr. Coggan would actually come into one of these discussions and provide helpful information. But, that isn't what he does. I refer to him as an academic bully. He will come in and make some cryptic comment implying that someone with a certain point of view is not only wrong but stupid. After several tries to get him to expand on why he thinks that he will generally post some graph that has not context (as he did in this thread) or tell people to go google something (as he did in this thread, something that google doesn't seem to find in this instance) or post a bunch of links to scientific articles, without any explanation. The problem is, if anyone has the background to go read and understand this stuff (as I do) and they go look at what he is referring too one finds that these references hardly ever address the specific issue being discussed or that Dr. Coggan has over interpreted what the paper says or, sometime, completely misinterpreted what the paper says. If one wants to discuss the nuances of these papers with him he just disappears. I happen to have an engineering and science background, and a medicine background with a special emphasis in metabolism and physiology (especially cardio/pulmonary physiology) and, having been an endurance athlete (albeit not an elite one), a passing interest in sports physiology and performance. Dr. Coggan doesn't like it that I want to discuss the details regarding his point of view so he seems to have decided that it is more effective to simply call me stupid.

The alternative - that you appear to be arguing - is that only unproven theories can be discussed in this thread and that anyone with real knowledge on the topic should stay away...

Phoeey, why would I argue that? I am interested in learning, if I wasn't I would keep my musings to myself. But, it is not enough for Dr. Coggan to come here and say: "trust me, this is the way it is", especially when he doesn't seem to understand what the question actually being asked was. Especially in a thread where one is speculating about the possibilities of doing something radically different. (If Coggan were advising Valery Brumel he would be saying "ignore that crazy Fosbury fellow, what he is doing hasn't been proven. The barrel roll is king (and technique doesn't matter anyway)") According to Dr. Coggan (and a few others) speculation and discussion is not allowed.

This is a thread about crank length and how it affects the cyclist. So, if Dr. Coggan has any "real knowledge" on the issue of crank length and all the ways it affects the cyclist let him come here and tell us in language we can all understand what that "real knowledge" is and what science it is based on. If he wants to participate let him actually add to the discussion instead of sniping. Otherwise, I will continue to push him for details and call him out as being the academic bully I believe him to be.

 

[CoachFergie]

Don't elevate yourself to the level of the true innovators of this world Frank.

You are only here to sell units and this has been a wildly amusing spam thread.

Your only scientific endeavour was to manipulate the data to support your theory on aerodynamics and you couldn't even do that right.

The evidence against your claim's has been presented here several times. Sorry you choose to bury your head in the sand.

I welcome Andy's frankness!

 

[CoachFergie]

Especially in a thread where one is speculating about the possibilities of doing something radically different. (If Coggan were advising Valery Brumel he would be saying "ignore that crazy Fosbury fellow, what he is doing hasn't been proven. The barrel roll is king (and technique doesn't matter anyway)")

What do you think happened when Fosbury did that jump. Biomechanists everywhere had a little orgasm and then started to study the technique and concluded it was a better than the scissor kick.

Just the same as when people researched crank length the current data would suggest this is a dead end in terms of investing time. Funny how the only person flogging this dead horse just happens to market cranks with adjustable length.

 

[coapman]

What do you think happened when Fosbury did that jump. Biomechanists everywhere had a little orgasm and then started to study the technique and concluded it was a better than the scissor kick.

But not before saying, if this technique is permitted we will have high jumpers around the world breaking their necks. Typical negative attitude.
In Anquetil's case, they could not study it because it revealed absolutely nothing, so the negative attitude continues today and attributes his TT success to everything but technique.

 

[coapman]

Aero is important.

Perhaps if you asked questions that had any relevance to form or fitness people would respond.

Aero did not result from "cycling research", it arose from work done by Boone Lennon in the triathlete camp. Until then cyclists, scientists and coaches were content with their shoulder bars and low profile TT bikes. What distinguishes a cycling coach from an athletic coach, not forgetting that pedaling technique is ignored and considered unimportant.

 

[coapman]

I thought my explanation was perfectly clear: the reason that things haven't changed is that, from an evolutionary perspective, humans haven't changed .

As Frank says, why can't you give a straight answer. What you are saying is, you believe it is impossible for the human body to apply max torque at 12 o'c when in the natural racing seated position? Which is why scientists including Martin wasted research time and still continue to waste it, attempting to create and perfect equipment that could partially compensate for this inability. The fact is, it is as easy if not easier to apply max torque at 12 than at 3 o'c while in that position.

 

[FrankDay]

I thought my explanation was perfectly clear: the reason that things haven't changed is that, from an evolutionary perspective, humans haven't changed .

In the history of human evolution, how long have humans been riding bicycles? What does human evolution have to do with how we ride or should ride bicycles? All evolution has done is determine what we have to work with when trying to figure out the best thing to do.

 

[coapman]

Just the same as when people researched crank length the current data would suggest this is a dead end in terms of investing time. Funny how the only person flogging this dead horse just happens to market cranks with adjustable length.

Frank is attempting to expand on Martin's research results by using them to improve the aerodynamic position of a rider without hindering performance. What's wrong with that ? On the other hand, I ask the question which A Coggan failed to answer, why do the longer cranks in the 145/195 range not improve performance? because it is not what one would expect to find. I believe that, like the dead spot sector, this could be directly linked to the pedaling technique used. I don't see it as a dead horse.

 

[TarmacExpert]

Anyhow, let's assume you are correct, drag increases as the legs get wider and wider and wider. What is the mechanism that explains this phenomenon (after all, frontal area doesn't change)?

I would dispute that frontal area doesn't change. At the top of the pedal stroke, if your legs are pointing outwards beyond a certain point, your thighs will present more frontal area than if they are pointing forwards. Also, if you channel air along the inside of the thigh, it strikes me that where it ends up isn't going to be great from an aerodynamic perspective, and you may well be better off having the outside of the thigh facing the wind rather than the inside, even if it's within a range of movement that doesn't change overall frontal area.

 

[FrankDay]

I would dispute that frontal area doesn't change. At the top of the pedal stroke, if your legs are pointing outwards beyond a certain point, your thighs will present more frontal area than if they are pointing forwards. Also, if you channel air along the inside of the thigh, it strikes me that where it ends up isn't going to be great from an aerodynamic perspective, and you may well be better off having the outside of the thigh facing the wind rather than the inside, even if it's within a range of movement that doesn't change overall frontal area.

Yes, shape is important, as is frontal area, when it comes to aerodynamics. Of course, Dr. Coggan hasn't given us any information to help us understand how the data on his chart was gathered to help us better understand it.

 

[acoggan]

Ah yes, if only that would happen, someone with the knowledge of Dr. Coggan would actually come into one of these discussions and provide helpful information. But, that isn't what he does. I refer to him as an academic bully. He will come in and make some cryptic comment implying that someone with a certain point of view is not only wrong but stupid. After several tries to get him to expand on why he thinks that he will generally post some graph that has not context (as he did in this thread) or tell people to go google something (as he did in this thread, something that google doesn't seem to find in this instance) or post a bunch of links to scientific articles, without any explanation. The problem is, if anyone has the background to go read and understand this stuff (as I do) and they go look at what he is referring too one finds that these references hardly ever address the specific issue being discussed or that Dr. Coggan has over interpreted what the paper says or, sometime, completely misinterpreted what the paper says.

When I was in graduate school, the faculty members constantly exhorted us to learn how to "synthesize". At the time, and even more so now, I've always felt that an innate talent, and not something that could be taught. You seem to be living proof of this.

I happen to have an engineering and science background, and a medicine background with a special emphasis in metabolism and physiology (especially cardio/pulmonary physiology) and, having been an endurance athlete (albeit not an elite one), a passing interest in sports physiology and performance.

We are all familiar with your checkered past in peripherally-related fields, just as we are all well aware that you are not licensed to practice medicine and have never published a scientific paper...you don't need to remind us.

(If Coggan were advising Valery Brumel he would be saying "ignore that crazy Fosbury fellow, what he is doing hasn't been proven. The barrel roll is king (and technique doesn't matter anyway)")

Cute story. In point-of-fact, however, I first experimented with shorter cranks almost 20 y ago, when Jim Martin originally suggested the idea. I was also one of the first (and one of the few) to have raced TTs using 'aero-or-die' handlebars, using Obree's Superman position, and/or the 'batwing' Tailwings skinsuit. I've also trained extensively in Obree's original position (never could get used to it), and have field-tested John Cobb's 'low sit' position (i.e., saddle height WAY below normal). To try to paint me as some sort of Luddite is therefore ridiculous.

This is a thread about crank length and how it affects the cyclist. So, if Dr. Coggan has any "real knowledge" on the issue of crank length and all the ways it affects the cyclist let him come here and tell us in language we can all understand what that "real knowledge" is and what science it is based on.

There really isn't anything I can add that hasn't already been said. That is, variations in crank length across the typical range have essentially no impact upon either maximal power or submaximal efficiency, nor do variations in crank length per se have a large effect on aerodynamic drag. For some people, a shorter crank can help "free up" their pedaling action when in the aero position, but it clearly isn't a panacea.

 

[acoggan]

I ask the question which A Coggan failed to answer, why do the longer cranks in the 145/195 range not improve performance? because it is not what one would expect to find.

I told you the answer - you just don't like it because it doesn't fit with your troll schtick.

 

[acoggan]

What you are saying is, you believe it is impossible for the human body to apply max torque at 12 o'c when in the natural racing seated position?

Yes, that is what I am saying.

 

[acoggan]

In the history of human evolution, how long have humans been riding bicycles? What does human evolution have to do with how we ride or should ride bicycles? All evolution has done is determine what we have to work with when trying to figure out the best thing to do.

Precisely my point.

 

[acoggan]

I welcome Andy's frankness!

Good thing you didn't write "Frank-ness", as that would have hurt my feelings.

 

[FrankDay]

There really isn't anything I can add that hasn't already been said. That is, variations in crank length across the typical range have essentially no impact upon either maximal power or submaximal efficiency, …

Prove that statement when one is considering what happens in the aero/TT position. While Martin's study did show a small variation over a large range one can assume his subjects were mostly upright (he did not specify), since he was measuring maximum power. If one were to repeat that study with cyclists in the TT position my guess is the results would be skewed even shorter and with larger variation. And, if one were to repeat that study looking at sustainable power in the aero position vs crank length I would expect the results to be skewed even shorter. Unless you can prove your above contention with real studies I would suggest that you are extrapolating from upright position data what you expect and simply blowing a lot of hot air our way through your computer keyboard. I mean, you do say

For some people, a shorter crank can help "free up" their pedaling action when in the aero position, but it clearly isn't a panacea.

Why on earth wouldn't you think that wouldn't have an effect on the amount of power they might be able to generate? And, if it did, why wouldn't it be a "panacea", at least for them?

 

[FrankDay]

To try to paint me as some sort of Luddite is therefore ridiculous.

I don't have a clue as to whether you are a Luddite or not in your personal life. All I know is how you behave on the internet.

 

[FrankDay]

In the history of human evolution, how long have humans been riding bicycles? What does human evolution have to do with how we ride or should ride bicycles? All evolution has done is determine what we have to work with when trying to figure out the best thing to do.

Precisely my point.

Then, would you agree, that pedaling technique is not "natural"? That what we do in pedaling a bicycle depends mostly on how we were taught when learning and not what God has predetermined, through evolution, is best for us?

 

[coapman]

I told you the answer - you just don't like it because it doesn't fit with your troll schtick.

Sorry now I get it, second time I made that error. Instead of restricting it to a change in gearing, I was including an increase in crank torque in each pedal stroke by switching pedaling technique. But there is no error in that claim of max torque through 12 o'c.

 

[coapman]

Sorry now I get it, second time I made that error. Instead of restricting it to a change in gearing, I was including an increase in crank torque in each pedal stroke by switching pedaling technique. But there is no error in that claim of max torque through 12 o'c.

Expanding on above statement. Martin's research results are based on natural pedaling techniques where max torque is applied with a vertical downward force between 2 -4 o'c and where only the lower body is used. With this technique changes in cadence are easier to make in keeping with the change in crank length. But if you are using a technique which can almost double the cumulative torque from each pedal stroke by starting max torque around 11 o'c, where forward and downward pedal forces are used, which uses both the upper and lower body in generating the crank torque and which works best using the higher gears, I don't believe you would get the same 'change of crank length' results.

 

[coapman]

All evolution has done is determine what we have to work with when trying to figure out the best thing to do.

That's true Frank. It gave us hands/arms and legs, but for some reason best known to themselves cycling scientists never considered making use of the arms to assist in generating crank torque.

 

[FrankDay]

That's true Frank. It gave us hands/arms and legs, but for some reason best known to themselves cycling scientists never considered making use of the arms to assist in generating crank torque.

Oh, I believe they have thought about using the hands and arms, just not in the same way you have. Your problem is you still haven't adequately described your technique nor shown there is any real benefit to your technique. And, the last is going to be especially hard if you are the only person in the world who is able to do the technique.

 

[TarmacExpert]

That is, variations in crank length across the typical range have essentially no impact upon either maximal power or submaximal efficiency

Prove that statement when one is considering what happens in the aero/TT position. While Martin's study did show a small variation over a large range one can assume his subjects were mostly upright (he did not specify), since he was measuring maximum power.

IMO Frank has a fair point, here, in that the results of Martin's study may well have been different with riders in the TT position.

nor do variations in crank length per se have a large effect on aerodynamic drag.

It depends what exactly you mean by large, of course, but I'm surprised you haven't thought it worthwhile to field test longer cranks. 190mm instead of 170mm would get your knee 4cm higher relative to your hip at the top of the pedal stroke (assuming you move both saddle and pads down 2cm), so if there were no adverse impact on power production, this might be expected to give a small but perhaps worthwhile aero gain.

 

[sciguy]

IMO Frank has a fair point, here, in that the results of Martin's study may well have been different with riders in the TT position.

This certainly would seem to be the case with athletes riding PowerCranks as so many of them seem to have difficulty riding in the aero position with them. That would imply to me that their power would be greatly reduced while attempting to ride with tight thigh/torso angle.

Here from a Slowtwitch forum poster:

"My personal experience was that I never got comfortable in the aero position. The PC's force you to completely unweight the recovering leg, so you're bearing a lot more weight on your bits than you would on normal cranks. This was the biggest revelation to me- how much work my legs were doing supporting part of my body weight vs propelling the bike. Consequently- I was never able to ride the PC's in the aero position. I rode them for months in the offseason on my road bike but was never able to transfer them to my tri bike. "

I think that we really need to run a series of experiments looking at how athlete's power duration curves are influenced riding PowerCranks versus fixed cranks at a variety of hip angles. I have a pretty good idea what the experiment results would show.