The crank length thread

[sciguy]

Yet you have, seemingly, done zero crank length testing. Y?

For the record, you're talking to a guy who owns and has done testing with sets of 155, 170, 172.5, 175 and 180mm cranks.

Hugh

 

[sciguy]

LOL. Your problem here, of course, is you need to come up with a study to show that such an adaption occurs regularly and uniformly with time as opposed to your anecdotal report.

Here is a study that looks at those who train in the aero position. There is certainly room for more research.

http://web.a.ebscohost.com/abstract...bnhnrOwV9i8R93jDEdKdSOLEr3KwMiHajizWw==&crl=c

There does not appear to be the normal metabolic cost associated with riding in an aero position when examining triathletes who train only in that position. From this study it can be recommended that cyclists and triathletes should train in the position in which they race.

Hugh

 

[FrankDay]

I don't see anything at all where SciGuy says that his setup works for everyone and that we should all be following his steps, only a statement that using a PM and HRM allows SciGuy to tweak HIS position easily using HIS OWN data collected BY HIMSELF, FOR HIMSELF.

This is the beauty of a measuring device Frank. You can tell if something works for you or not BY YOURSELF. If you tried one for a while you might just get it.

I posted two studies that say that people lose power when they go into the aero position and it is my assertion that this can be mitigated by going to shorter cranks. Sciguy then posts that he has found that his own testing using a power meter

Many of us who train with power see that increased metabolic cost of riding aero greatly diminish if not completely vanish with time spent training in the aero postion.

he has found that this drop returns to NEARLY EQUIVALENT levels after a short period of training in the position, as if to imply that this is a non-issue for everyone, especially if they have a power meter. His statement was nothing more than hearsay and his own anecdotal result (the fact he has a power meter does not make it anything more than an anecdote

Anecdotal evidence is an informal account of evidence in the form of an anecdote. The term is often used in contrast to scientific evidence, as evidence that cannot be investigated using the scientific method. The problem with arguing based on anecdotal evidence is that anecdotal evidence is not necessarily typical; only statistical evidence can determine how typical something is.

So, in effect, he tried to put down my presentation of scientific evidence with anecdote.

Note that I have not claimed that power would drop for everyone as they go to the aero position but only that it will probably drop for most and that each person should test themselves to see what happens to them and whether crank length is an important component for them in their aerodynamic/power trade off equation. Why you guys are fighting this so hard is baffling except when I consider your concern over this argument that if I am right on this I might be right, also, regarding PowerCranks. It is important to try to destroy any credibility I might have in any of these debates rather than agree that I might actually have a point.

 

[FrankDay]

Here is a study that looks at those who train in the aero position. There is certainly room for more research.

http://web.a.ebscohost.com/abstract...bnhnrOwV9i8R93jDEdKdSOLEr3KwMiHajizWw==&crl=c



Hugh

That is cool. Unfortunately that study says nothing about there being a potential metabolic cost to crank length in the aero position. In fact, it doesn't appear the study defined what they meant by aero position (angles, drop, etc.) such that it really means nothing. Just because someone is on the aerobars does not necessarily mean they are particularly aero. We adapt to how we train but that is not evidence that what we are doing is optimal.

 

[elapid]

Note that I have not claimed that power would drop for everyone as they go to the aero position but only that it will probably drop for most and that each person should test themselves to see what happens to them and whether crank length is an important component for them in their aerodynamic/power trade off equation.

So you're saying to do exactly what SciGuy has done, but then you complain about what he has done?

 

[FrankDay]

So you're saying to do exactly what SciGuy has done, but then you complain about what he has done?

No, what I am complaining about was the implication in his post, that his testing suggested that this crank length stuff was nothing to worry about.

 

[FrankDay]

For the record, you're talking to a guy who owns and has done testing with sets of 155, 170, 172.5, 175 and 180mm cranks.

Hugh

Why don't you post your actual data from your testing from all those different crank lengths both upright and aero and let us see what your numbers are.

 

[CoachFergie]

Here is a study that looks at those who train in the aero position. There is certainly room for more research.

http://web.a.ebscohost.com/abstract...bnhnrOwV9i8R93jDEdKdSOLEr3KwMiHajizWw==&crl=c



Hugh

Thanks Hugh, more evidence that crank length isn't really that important of a deal. Bit like cleat placement and cadence, just choose what you like but don't go either way in the extreme. Science is cool!

 

[sciguy]

And, another paper that supports the last one.Would shorter cranks mitigate this effect? My hypothesis is a big fat YES!

Hmmmmm the title gives me pause right off the bat.

Body position affects performance in untrained cyclists

 

[FrankDay]

Hmmmmm the title gives me pause right off the bat.

Body position affects performance in untrained cyclists

Of course the first paper was about

In this study, 14 elite male bicycle racers…

Do you think it possible that because we have two papers with essentially the same results, one studying ELITE cyclists and the other studying UNTRAINED cyclists, that, as a general rule, this "problem" applies to EVERYBODY?

 

[hiero2]

Of course the first paper was about
Do you think it possible that because we have two papers with essentially the same results, one studying ELITE cyclists and the other studying UNTRAINED cyclists, that, as a general rule, this "problem" applies to EVERYBODY?

Frank, that was an excellently brief answer.

I can just hear the turtle, in "Tortoise Beats Hare", starring our fav, Bugs himself, going "Meeeeeehhhhhhhhhhhh. It's a POSSIBILITY!"

Of course, one can't make the assumption that it DOES, but it is possible.

 

[FrankDay]

FOf course, one can't make the assumption that it DOES, but it is possible.

In the absence of any studies to the contrary, based upon the available evidence, wouldn't the prudent scientist be forced to draw that conclusion (make that assumption)? Of course, one would like more evidence (and more is coming I am told) but based upon what is available now what other conclusion makes any rational sense?

Edit: By EVERYONE I mean everyone in the metaphorical sense. Of course, there will be outliers - there always are. We are talking about a general rule that applies to the majority of people.

 

[hiero2]

In the absence of any studies to the contrary, based upon the available evidence, wouldn't the prudent scientist be forced to draw that conclusion (make that assumption)? Of course, one would like more evidence (and more is coming I am told) but based upon what is available now what other conclusion makes any rational sense?

Edit: By EVERYONE I mean everyone in the metaphorical sense. Of course, there will be outliers - there always are. We are talking about a general rule that applies to the majority of people.

Ah, no. The prudent scientific mind refrains from drawing conclusions based on minimal or questionable evidence. However, that does not mean that a rational and reasonable position might INFER an answer based on minimal or missing evidence. Many highly qualified people mistake the two - and it is my opinion that the medical community makes a practice of mistaking the two.

Ultimately, off the top of my head, I think the difference between the two gets down to certainty. Science is built upon evidence, repeatable evidence. Logic and reason, on the other hand, can be the tool of a Sophist.

 

[FrankDay]

Ah, no. The prudent scientific mind refrains from drawing conclusions based on minimal or questionable evidence. However, that does not mean that a rational and reasonable position might INFER an answer based on minimal or missing evidence. Many highly qualified people mistake the two - and it is my opinion that the medical community makes a practice of mistaking the two.

Ultimately, off the top of my head, I think the difference between the two gets down to certainty. Science is built upon evidence, repeatable evidence. Logic and reason, on the other hand, can be the tool of a Sophist.

I accept your argument. Hardly anything in science is certain. Even the absolute nature of the speed of light is somewhat controversial. As one gets into the biological sciences certainty is even harder to come by. The best anyone can do is infer based on inadequate data and the data is always inadequate. Yet some here are convinced that science has absolutely proven certain concepts regarding cycling and any view apart from the majority (or their own) is surely the view of a crack-pot at best and crack-pot troll at worst. Whenever someone is presented with a study that purports to "prove" something the first question they should ask themselves is "what are the weaknesses of the study?" The problem is that we are forced to make decisions based upon inadequate data so I think it is human nature to avoid admitting that we don't know very much and, instead, delude ourselves into believing our current understanding has to be correct.

 

[elapid]

I accept your argument. Hardly anything in science is certain. Even the absolute nature of the speed of light is somewhat controversial. As one gets into the biological sciences certainty is even harder to come by. The best anyone can do is infer based on inadequate data and the data is always inadequate. Yet some here are convinced that science has absolutely proven certain concepts regarding cycling and any view apart from the majority (or their own) is surely the view of a crack-pot at best and crack-pot troll at worst. Whenever someone is presented with a study that purports to "prove" something the first question they should ask themselves is "what are the weaknesses of the study?" The problem is that we are forced to make decisions based upon inadequate data so I think it is human nature to avoid admitting that we don't know very much and, instead, delude ourselves into believing our current understanding has to be correct.

While I agree with you regarding the uncertainty of scientific studies and their weaknesses, for these will always exist, these will always be more meaningful than your anecdotes. All studies, whether the results are negative or positive, are intended to add to our knowledge base. Hopefully from this, more questions are asked and more studies are done to answers these questions, so on and so forth. Rarely is a study so conclusive that researchers abandon that topic forever more. So while you may not accept the studies that have been published, and they will naturally have their weakness like any other study, they provide a level of information that far surpasses anything that you have been able to offer.

 

[FrankDay]

While I agree with you regarding the uncertainty of scientific studies and their weaknesses, for these will always exist, these will always be more meaningful than your anecdotes.

Only when studies exist are they more meaningful than anecdotes. And then, some studies are so awful (how about those with fabricated data) that they are hardly any more useful. Scientists are supposed to be first and foremost great observers. Anecdotes are part of the observing process that leads to new insights.

All studies, whether the results are negative or positive, are intended to add to our knowledge base. Hopefully from this, more questions are asked and more studies are done to answers these questions, so on and so forth. Rarely is a study so conclusive that researchers abandon that topic forever more.

You should be telling that to CoachFergie, not me.

So while you may not accept the studies that have been published, and they will naturally have their weakness like any other study, they provide a level of information that far surpasses anything that you have been able to offer.

What study have I failed to accept?

 

[elapid]

And then, some studies are so awful (how about those with fabricated data) that they are hardly any more useful.

What study with fabricated data? Any study using fabricated data should be immediately withdrawn from that publication.

What study have I failed to accept?

Nearly every study that disagrees with your point-of-view.

 

[FrankDay]

What study with fabricated data? Any study using fabricated data should be immediately withdrawn from that publication.

How about this guy, Hwang Woo-suk, infamous for faking his research in cloning and getting into some of the most prestigious journals in the world. It happens.

Nearly every study that disagrees with your point-of-view.

I am not aware of any study that disagrees with my point of view. Could you give me a specific example?

 

[FrankDay]

Nearly every study that disagrees with your point-of-view.

Again, can you give me an example of a study that disagrees with my point of view?

I think you are confusing my disagreeing with how others have interpreted these studies with my disagreeing with the study. For instance, I agree that an elite cyclist using my cranks 2 hours a week for 5 weeks (10 hours intervention) should expect no improvement in that time frame. I disagree that this study proves anything about the product when used as we recommend (immersion) for the period of time we recommend (6-9 months).

Perhaps you would like to discuss Luttrell, which demonstrated an increase in cycling efficiency in much lesser capable cyclists after 3 hours a week for 6 weeks. (18 hours intervention)

Or Dixon, which showed increases in power and VO2max in elite cyclists after 6 weeks of immersion training. (60 hours approximate intervention)

If you have another example of a study that disagrees with my point of view, let me know and we can discuss.

 

[kilibo77]

I am not familiar with this thread, but I try to listen

 

[FrankDay]

One of the frequent objections to going shorter has to do with losing leverage, longer crank length means more leverage so more torque for same pushing force. Of course, that holds true only as long as one can push just as hard with the longer crank length.

I was thinking about this and trying to come up with a test people could do that might lead them to considering they need to go shorter. So I came up with this test. Stand against a wall with your knees bent about the same as they are when you pedal is at the bottom of the stroke. Mark your height. Then, lower yourself until your knees start to feel the strain, and mark this height. Your pushing down force didn't change (half your weight) but the effort needed to do so certainly did. So, this seems to be a good indicator of the ROM of the knee for effective force application. If you can't push as hard the advantages of longer cranks becomes smaller and smaller or, eventually, negative.

I am 6'2" (1.9m) have come to the conclusion that 130 mm cranks are near my optimum. Doing this test, I measured a 135mm distance change. Seems like it is a good test for me.

I would be interested in seeing what others find doing this test and what they think regarding this as a screening test for a crank length starting point.

 

[sciguy]

I believe that what I found was that there was no aerodynamic benefit to going shorter once the upper body was in a very good (reasonably flat) aerodynamic position. The improvements in the upper body would be canceled by the detriments seen from the leg changes. (Edit: Once this condition is reached the only reason to go shorter would be if one saw a power increase or an improvement in comfort with shorter cranks.) However, for those who have relatively poor upper body positions because of poor flexibility or other reasons going shorter, if it helps them achieve a much better upper body position, can still result in an aerodynamic benefit because the upper body improvements should outweigh the leg decreases. So, it depends upon where you are starting. Looking at the average age-group triathlete I believe many of them would see substantial aerodynamic improvement from going to shorter cranks if that allowed them to get their torso/head lower..

Frank,

Other than allowing one to be aero with a rather substantial beer gut, how is it that you think shorter cranks allow one to achieve a much better upper body position? What mechanism are you evoking to cause the improvement?

Hugh

 

[FrankDay]

Frank,

Other than allowing one to be aero with a rather substantial beer gut, how is it that you think shorter cranks allow one to achieve a much better upper body position? What mechanism are you evoking to cause the improvement?

Hugh

There are many many things competing here. Beer gut is just one of them. How loose the ligaments and tendons are would be another (some people can put their hands flat on the floor while others can barely touch their ankles when trying to touch their toes). Injury and disease also come into play.

Anyhow, it is my belief that many people lose power as they try to get lower for better aerodynamics for any of various reasons. I believe that shorter cranks can minimize this power loss, allowing the rider to attain a better aerodynamic position while maintaining higher power for the riders seeing these changes. Seems win-win to me.

 

[Hawkwood]

Buying new chainset, advice needed

I have been following the crank length debate with some interest. My history is that I used 170mm from 1976 to 1982, 175mm 1982 to 1985, and 180mm from 1985 to now. I'm 186cm tall, with an inside leg measurement of 93cm. I raced up to 2000, but now cycle to keep fit. I do go out with clubs once in a while for some faster miles, and these normally degenerate into semi races. I am fairly good on shorter punchier climbs, and also getting down on the hoods into a head wind. I ride a compact set-up nowadays. I like 180mm cranks, I think they give me an extra tooth or two on climbs, but that's entirely subjective. In terms of making a purchase 170 and 175 cranks are much easier to come by in compact (and cheaper generally). I have a Campagnolo set-up and Chorus and Record compact chainsets are available at tempting prices in 170mm and 175mm.

So what are your thoughts, would dropping to 175 or 170 make much difference, or given that I've been on 180s for almost 30 years should I stick with them?

 

[FrankDay]

I have been following the crank length debate with some interest. My history is that I used 170mm from 1976 to 1982, 175mm 1982 to 1985, and 180mm from 1985 to now. I'm 186cm tall, with an inside leg measurement of 93cm. I raced up to 2000, but now cycle to keep fit. I do go out with clubs once in a while for some faster miles, and these normally degenerate into semi races. I am fairly good on shorter punchier climbs, and also getting down on the hoods into a head wind. I ride a compact set-up nowadays. I like 180mm cranks, I think they give me an extra tooth or two on climbs, but that's entirely subjective. In terms of making a purchase 170 and 175 cranks are much easier to come by in compact (and cheaper generally). I have a Campagnolo set-up and Chorus and Record compact chainsets are available at tempting prices in 170mm and 175mm.

So what are your thoughts, would dropping to 175 or 170 make much difference, or given that I've been on 180s for almost 30 years should I stick with them?

IMHO, you could stay with any of these lengths without much issue because, unless your cranks are way too long (which they don't seem to be) crank length has little impact on power (and, besides, you are no longer racing but mostly riding for fitness) and you are not trying to optimize your TT position. From my perspective crank length is only a major issue for the shorter of the species or those trying to optimize TT position, or both.