The importance of crank length to the cyclist.

[FrankDay]

Frank, they were attached to the pedals (using cleats).
And most of these guys are high level rowers, at least state level, most have been national reps here in Aus.
Comparing the training adaptation of muscles due to 1-2 bike rides per week, maybe 5 hours tops, vs 8-12 rowing sessions (on water and indoor). If anything, the results would have been skewed in favor of longer crank lengths.

Thanks for the f/u. I see several areas for follow-up when "looking" at your data and those other studies found in the Martin slide show.

First, having been a rower in college, there is no one better suited to maximizing a long range of motion push than a rower. But, they typically are pushing in the 30-40 rep/min range, not 95-100 (and that pushing is constrained to a linear, not circular, motion). So, there is a substantial deviation from how they are maximally trained as athletes to how they are being tested as cyclists. Despite this, if any group were to test better on long cranks one would expect it to be trained rowers. They did not.

Second, no one has looked at the interaction of crank length as it applies to different riding positions, specifically the traditional riding position vs the aerodynamic TT position. People here are presuming that data obtained in the upright position applies also to the aerodynamic position. It is my impression that the TT position maximizes the effect of crank length on power and this data will make the short crank look even better.

Third, it would appear that how one has been trained to pedal may affect this data. In your study and the studies of Martin this is not taken into account in their data and one can presume that all the data is taken from "mashers". From the Martin and your data it would appear that power/efficiency can be maintained/maximized down to a crank length of about 145. However, some preliminary data coming from someone looking at this in people trained on independent cranks seems to be showing crank length can go much shorter than 145 before power loss is seen.

And, if folks like Fergie continue to focus on the power issue only they will miss out on the real benefit of this change, as I see it, the ability to improve aerodynamics. It is the interaction of power and aerodynamics that are the main determinants of how fast a single rider can go. Even if power were to drop some with shorter cranks it is possible the rider might race better if this change allowed for much better aerodynamics. One cannot know without trying, the whole point of this thread.

Anyhow, Shady, thanks for your input - nice to see a fresh name and viewpoint.

 

[CoachFergie]

Third, it would appear that how one has been trained to pedal may affect this data. In your study and the studies of Martin this is not taken into account in their data and one can presume that all the data is taken from "mashers". From the Martin and your data it would appear that power/efficiency can be maintained/maximized down to a crank length of about 145. However, some preliminary data coming from someone looking at this in people trained on independent cranks seems to be showing crank length can go much shorter than 145 before power loss is seen.

Highly amusing what you call data compared to what real researchers call data.

And, if folks like Fergie continue to focus on the power issue only they will miss out on the real benefit of this change, as I see it, the ability to improve aerodynamics. It is the interaction of power and aerodynamics that are the main determinants of how fast a single rider can go. Even if power were to drop some with shorter cranks it is possible the rider might race better if this change allowed for much better aerodynamics. One cannot know without trying, the whole point of this thread.

Yup all that time in the wind tunnel at the Canterbury Uni Engineering Dept was just for s**ts and giggles.

You continue to delude yourself that Gimmickcranks (and this is just another lame attempt to sell product) are the only way to improve performance on the bike.

In summary I feel that shorter cranks do several things for the cyclist.

1. Shorter cranks will improve power output for most.
2. Although this goes completely against the conventional wisdom, shorter cranks can reduce knee stress
3. Shorter cranks allow better aerodynamic positioning without sacrificing power.

You contradict yourself again on points 1 and 3. Keep up the "performance artist" show Frank.

 

[FrankDay]

Highly amusing what you call data compared to what real researchers call data.

To me, in this setting, data is simply information upon which inferences may or may not be made and conclusions drawn in the manner of #1 below. Perhaps you can enlighten me as to what real researchers call data.

Definition of DATA
1: factual information (as measurements or statistics) used as a basis for reasoning, discussion, or calculation <the data is plentiful and easily available — H. A. Gleason, Jr.> <comprehensive data on economic growth have been published — N. H. Jacoby>
2: information output by a sensing device or organ that includes both useful and irrelevant or redundant information and must be processed to be meaningful
3: information in numerical form that can be digitally transmitted or processed

 

[CoachFergie]

Great to see you can use a dictionary Frank. Doesn't make your data any less irrelevant.

 

[FrankDay]

Great to see you can use a dictionary Frank. Doesn't make your data any less irrelevant.

Fergie, in case you haven't noticed, this is an internet forum - not a world class research facility. Seems my use of my "data" here does fit the definition of 1: factual information used as a basis for reasoning, discussion, or calculation. If you think the data is irrelevant perhaps you should join the discussion and say why you think so?

 

[CoachFergie]

When others are presenting their data which is valid and reliable your attempts to suggest times and speeds for different days or heart rate are just amateurish.

You have presented nothing to support your original beliefs. This is fairly typical.

 

[FrankDay]

When others are presenting their data which is valid and reliable your attempts to suggest times and speeds for different days or heart rate are just amateurish.

You have presented nothing to support your original beliefs. This is fairly typical.

All I am presenting are reports by people that suggest there is something to my argument. It is, obviously, not proof. But, these reports are a basis for further discussion. It would be simple enough for you to present some reports from people who tried the experiment and reported that they got slower in rebuttal if you so desired. Instead, all you do is complain about the quality of the data. That, my friend, is amateurish. If you don't like the quality of the data then gather your own, better quality, data and present it.

 

[CoachFergie]

All I am presenting are reports by people that suggest there is something to my argument. It is, obviously, not proof. But, these reports are a basis for further discussion. It would be simple enough for you to present some reports from people who tried the experiment and reported that they got slower in rebuttal if you so desired. Instead, all you do is complain about the quality of the data. That, my friend, is amateurish. If you don't like the quality of the data then gather your own, better quality, data and present it.

The reason I am a Professional cycling coach (people pay me) is because I provide valid and reliable data.

"Yes you have improved 10 watts for your 3000m IP"

"Yes you have lowered your cda from .3 to .29 and can maintain the same power output in the more aerodynamic position"

"Yes those wheels mean you can sustain a higher speed at a given wattage than the other wheels"

Compared to...

"Ummmm your time is faster than 2 months ago so I believe you are faster"

"Well your heart rate is two beats lower than the first test so I think you are more efficient"

"Errr you are 3mph faster than the start of the season so the <insert Gimmick du jour here> must be the reason".

 

[FrankDay]

The reason I am a Professional cycling coach (people pay me) is because I provide valid and reliable data.

Fergie, you are truly crazy. I try to initiate a theoretical discussion as to where I think a lot of cyclists can see some "easy" improvement and you argue that people pay you to coach them so everyone should listen to you. Well, people (even some professional cyclists) pay me for my product and many come back and buy more than one so everyone should listen to me.

This is a theoretical argument. The support is anecdotal. It will pique your interest or it won't. I guess another possibility is it will pique even more resentment that I am still here.

 

[CoachFergie]

Fergie, you are truly crazy. I try to initiate a theoretical discussion as to where I think a lot of cyclists can see some "easy" improvement and you argue that people pay you to coach them so everyone should listen to you.

You start these debates to try and sell Gimmickcranks, pure and simple.

Whether a coach is paid or how much they are paid is no indication of whether they are worth listening to. The quality of any discussion is the evidence that one can supply to support their position. You have provided no evidence of these "easy" improvements.

This is a theoretical argument. The support is anecdotal.

The real research that takes place outside of your imagination would suggest that your theories are incorrect.

 

[oldborn]

Awesome Mrs Fargo is getting angry, cool down dude, no one is listening to you, why would?

 

[Captain Serious]

I can't find the quote, so don't shoot me, but I think John Cobb says that almost all the riders he's put on 165mm tested more aero, obviously because they could lower their upper bodies due to better thigh/waist clearance at the top of the pedal stroke

 

[FrankDay]

I can't find the quote, so don't shoot me, but I think John Cobb says that almost all the riders he's put on 165mm tested more aero, obviously because they could lower their upper bodies due to better thigh/waist clearance at the top of the pedal stroke

Here is an excerpt from an article in triathlete magazine about this. I asked John Cobb directly about this and he said essentially all the measured improvement came about from being able to put the athlete into a more compact position (as stated in the article and theorized by me). He did not remember what the crank lengths involved were in this specific instance. (note: there is probably a typo in the article in that "decrease" should probably read "increase"

 

[Captain Serious]

Thanks.
A 30% reduction in drag?! Crikey!!

 

[oldborn]

Let see how some anonymous Dude on blog understand this question.

Raw data at 85%Vo2Max



Data curve if 170mm cranks would be optimal


Data curve if longer cranks then 170mm are better.


Data curve if shorter cranks then 170mm are better


Just more thoughts and the jury is still out.

 

[FrankDay]

Let see how some anonymous Dude on blog understand this question.

Raw data at 85%Vo2Max

[Image removed to comply with forum 4 images only rule]

Data curve if 170mm cranks would be optimal


Data curve if longer cranks then 170mm are better.


Data curve if shorter cranks then 170mm are better


Just more thoughts and the jury is still out.

Compare those thoughts to the actual data of Martin

One might conclude from this, it seems, that cranks less than 170 mm "are better" (and this conclusion ignores any aerodynamic effect associated with crank length).

 

[CoachFergie]

But Martin didn't conclude that did he because the differences were not statistically significant.

 

[Captain Serious]

Are those numbers for seated or standing pedalling?

 

[Oldman]

Are those numbers for seated or standing pedalling?

Don't ask the Salesman real world questions or applications. His supplicants provide him with testimonials that say his PC cranks work and that's good enough. That and the idea that crank length alone will significantly lower your aero position.

 

[oldborn]

That paper sugest that even 145mm cranks were match to "standard" 170mm which is all, before decades that Martin guy or just idea would be crazy.
I think it is worth to discuss
Fortunately Spanish Inquisition is out of license

Any real coach here to discuss?

 

[CoachFergie]

Don't ask the Salesman real world questions or applications. His supplicants provide him with testimonials that say his PC cranks work and that's good enough. That and the idea that crank length alone will significantly lower your aero position.

All I had to do to lower my position in front was follow John Cobb's advice to tilt the saddle "up" at the front and also have a greater hip angle, flatter back and dropped my bars by 4cm! Free speed!!!

 

[FrankDay]

Are those numbers for seated or standing pedalling?

Capt Serious, I am quite certain Martin's data is for seated 1 rep max power.

But Martin didn't conclude that did he because the differences were not statistically significant.

Fergie, you aren't trying to suggest that a paper's author's interpretation of his data is the only possible correct one are you? While the power differences between 170 and 145mm did not reach the 0.05 statistical significance difference required of a scientific paper before one is allowed by the editors to declare a difference has been "proven" the simple failure to reach that level is not proof a real difference does not exist. As pointed out in an earlier post by someone else, the simple shape of Martin's data curve suggests a real difference exists. As I have stated before, I believe Martin should have concluded that this deserves further study.

All I had to do to lower my position in front was follow John Cobb's advice to tilt the saddle "up" at the front and also have a greater hip angle, flatter back and dropped my bars by 4cm! Free speed!!!

What does that have to do with this discussion? Perhaps both changes would be beneficial. Wouldn't work for me though as if I tilt the saddle up I am so uncomfortable on the bike I wouldn't be able to go for more than a mile or two without stopping. I need the nose down for simple comfort reasons.

 

[FrankDay]

All I had to do to lower my position in front was follow John Cobb's advice to tilt the saddle "up" at the front and also have a greater hip angle, flatter back and dropped my bars by 4cm! Free speed!!!

I would be interested in seeing some before and after pictures of this simple change resulting in this radical lowering up front.

Also, do you have data to show what happened to your ability to generate power with this change?

 

[Captain Serious]

Capt Serious, I am quite certain Martin's data is for seated 1 rep max power.

thanks

(*post minimum 10 characters*)

 

[oldborn]

UCI is looking for World team coach consist of Basso, Evans and Cancellara VS Superman, Batman and Mutant Ninja Turtles. Do not you think you are No1contender. Get that job Fargo