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The importance of crank length to the cyclist.

Moderator: King Boonen

18 Feb 2013 18:54

FrankDay wrote:Really? News to me.


Ha ha, so you voluntarily stopped starting SPAM threads on Slowtwitch:D
Hamish Ferguson
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18 Feb 2013 23:05

FrankDay wrote:Really? News to me.



Well perhaps not banned per se but it's pretty clear Dan does not want you bringing up PowerCranks ever again.

"but if that's not enough for you - for those of you who demand to talk about powercranks anyway, notwithstanding all that has been written here and all the grief that these discussions have caused me, and my moderators, and all those who complain about the bad comportment of one side or the other - frankly, if that's your imperative in order to remain a member of this community, good riddance to you.


Dan Empfield
aka Slowman "

Whole post can be found here.

http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=3155163#3155163
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19 Feb 2013 01:23

sciguy wrote:Well perhaps not banned per se but it's pretty clear Dan does not want you bringing up PowerCranks ever again.

"but if that's not enough for you - for those of you who demand to talk about powercranks anyway, notwithstanding all that has been written here and all the grief that these discussions have caused me, and my moderators, and all those who complain about the bad comportment of one side or the other - frankly, if that's your imperative in order to remain a member of this community, good riddance to you.


Dan Empfield
aka Slowman "

Whole post can be found here.

http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=3155163#3155163
The problem was not with me (in my opinion, of course) but I simply could not post an contrary view on almost any topic without someone else bringing PC's into the discussion and then things would degenerate. The fact that almost any topic I participated in, whether initially related to PC's or not, would degenerate into a PC thread, was "ruining his brand". Unfortunately for me, Dan simply could not enforce the forum rules when it came to others attacking me without any evidence (despite my requests for the moderators to do so) since several of those were forum favorites including his favorite pro and employee.

Slowtwitch used to be the go to place where knowledgeable people could discuss almost any topic related to cycling/triathlon heatedly. Not so anymore. Most of the best, IMHO, are gone.
Life is short, both reading my posts and training with PowerCranks will make it seem longer
FrankDay
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19 Feb 2013 01:34

CoachFergie wrote:Yet you continually ignore Dr Martin's presentation on crank length and pedalling technique which sums up rather nicely why your claims have no scientific basis. Rather classic was when you said you where only aware of Dr Martins original study on the subject when he has done or been involved in several studies on crank length where no data has been presented that crank length or pedalling technique is of any importance to cycling performance.
I don't ignore Martin's presentation. I have, using his own data, simply drawn a different conclusion than him as I am not hampered by the need to reach the P<0.05 "statistically significant" requirement to think something potentially important. And, actually, our conclusions are not that different as Martin now also suggests that crank length might be important as regards aerodynamics. So, whether power changes significantly or not with crank length Martin and I agree that aerodynamics might. I believe if Martin had more people in his study or if he had tested them in the aerodynamic position (or both) he would probably have seen a statistically significant difference in power between 170 and 145 mm crank length. One of the nice things about science is different people can look at the same data and reach totally different conclusions. Additional studies will then be necessary to determine which conclusion is most correct. Those have not been done.
Life is short, both reading my posts and training with PowerCranks will make it seem longer
FrankDay
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19 Feb 2013 01:42

FrankDay wrote:I don't ignore Martin's presentation. I have, using his own data, simply drawn a different conclusion than him as I am not hampered by the need to reach the P<0.05 "statistically significant" requirement to think something potentially important.


Good thing that Dr Martin suggested that there might be a .5% at best performance improvement from a change in crank length for only the very tallest and very shortest of cyclists. Not very important at all.

I believe if Martin had more people in his study or if he had tested them in the aerodynamic position (or both) he would probably have seen a statistically significant difference in power between 170 and 145 mm crank length.


Speculation.

One of the nice things about science is different people can look at the same data and reach totally different conclusions. Additional studies will then be necessary to determine which conclusion is most correct. Those have not been done.


Martin and others have performed several studies. Odd that you would hinge your argument on one study. Laziness?
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19 Feb 2013 01:45

FrankDay wrote:The problem was not with me (in my opinion, of course) but I simply could not post an contrary view on almost any topic without someone else bringing PC's into the discussion and then things would degenerate. Dan simply could not enforce the forum rules when it came to others attacking me without any evidence (despite my requests for the moderators to do so) since several of those were forum favorites including his favorite pro and employee.


Perhaps the lack of supporting evidence for your claims was an inspiration to the others.
Hamish Ferguson
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19 Feb 2013 02:09

CoachFergie wrote:Perhaps the lack of supporting evidence for your claims was an inspiration to the others.
The rule was that one couldn't say anything bad about a triathlon related company (unless it was a personal experience) without substantial proof. Calling PowerCranks the many various names (you were amongst the worst) seen, etc. without proof or other substantial evidence simply violated the forum rules yet those posts were never pulled, requiring a response from me. To point out the "lack of supporting evidence" (at least in your opinion) is one thing. To call them snake oil, etc., is another. When users came and posted positive experiences with the product they were typically and viciously attacked and there were no consequences to calling people liars, shills, etc. If the ST forum rules had been honestly and equally applied there would not have been a PowerCranks problem. IMHO, Dan didn't have the cajones to stand up to his friends.
Life is short, both reading my posts and training with PowerCranks will make it seem longer
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19 Feb 2013 02:18

CoachFergie wrote:
I don't ignore Martin's presentation. I have, using his own data, simply drawn a different conclusion than him as I am not hampered by the need to reach the P<0.05 "statistically significant" requirement to think something potentially important.

Good thing that Dr Martin suggested that there might be a .5% at best performance improvement from a change in crank length for only the very tallest and very shortest of cyclists. Not very important at all.
So, let me get this straight, you are willing to give up or not pursue power improvements because you think them small?

I believe if Martin had more people in his study or if he had tested them in the aerodynamic position (or both) he would probably have seen a statistically significant difference in power between 170 and 145 mm crank length.


Speculation.
True, but isn't that where improvements come from, someone speculating that "if I do this I might be better"?

One of the nice things about science is different people can look at the same data and reach totally different conclusions. Additional studies will then be necessary to determine which conclusion is most correct. Those have not been done.

Martin and others have performed several studies. Odd that you would hinge your argument on one study. Laziness?
I think most of Martin's "studies" come from one set of data. Anyhow, the data set I have based my speculation on has yet to be refuted. The laziness, if it should be applied anywhere, should be cast on those who don't believe this data but have yet to try to refute it.
Life is short, both reading my posts and training with PowerCranks will make it seem longer
FrankDay
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19 Feb 2013 02:58

FrankDay wrote:The rule was that one couldn't say anything bad about a triathlon related company (unless it was a personal experience) without substantial proof. Calling PowerCranks the many various names (you were amongst the worst) seen, etc. without proof or other substantial evidence simply violated the forum rules yet those posts were never pulled, requiring a response from me. To point out the "lack of supporting evidence" (at least in your opinion) is one thing. To call them snake oil, etc., is another. When users came and posted positive experiences with the product they were typically and viciously attacked and there were no consequences to calling people liars, shills, etc. If the ST forum rules had been honestly and equally applied there would not have been a PowerCranks problem. IMHO, Dan didn't have the cajones to stand up to his friends.


Nice spin, I would sumit that your nonsense claim of a 40% improvement is the best evidence of Snake Oil Salesmanship in cycling forum history.
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19 Feb 2013 03:06

FrankDay wrote:So, let me get this straight, you are willing to give up or not pursue power improvements because you think them small?True, but isn't that where improvements come from, someone speculating that "if I do this I might be better"?I think most of Martin's "studies" come from one set of data. Anyhow, the data set I have based my speculation on has yet to be refuted. The laziness, if it should be applied anywhere, should be cast on those who don't believe this data but have yet to try to refute it.


I am not refuting Dr Martin or his conclusions.

People have been presenting data since 2003 refuting your claims re Gimmickcranks.

As a coach and a Sport Scientist in training I look at the smallest worthwhile improvement. .5% for the tallest or shortest rider changing from a 170mm crank is not it.
Hamish Ferguson
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19 Feb 2013 17:15

CoachFergie wrote:As a coach and a Sport Scientist in training I look at the smallest worthwhile improvement. .5% for the tallest or shortest rider changing from a 170mm crank is not it.
You mean you are looking for smaller improvements than this? No wonder you are ignoring the potential aero improvements of this change, too large for you.
Life is short, both reading my posts and training with PowerCranks will make it seem longer
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22 Feb 2013 19:57

Another anecdotal report.

http://forum.slowtwitch.com/forum/Slowtwitch_Forums_C1/Triathlon_Forum_F1/140_cranks_-_not_bad_at_all_P4439838/

The remark I would make is he should probably be moving his seat back, not forwards. But, he will eventually figure this out if he stays with this.
Life is short, both reading my posts and training with PowerCranks will make it seem longer
FrankDay
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22 Feb 2013 20:05

How does this contribute to the debate about your claimed importance of crank length?
Hamish Ferguson
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22 Feb 2013 20:47

FrankDay wrote:Another anecdotal report.

http://forum.slowtwitch.com/forum/Slowtwitch_Forums_C1/Triathlon_Forum_F1/140_cranks_-_not_bad_at_all_P4439838/

The remark I would make is he should probably be moving his seat back, not forwards. But, he will eventually figure this out if he stays with this.


[color="Black"]She[/color] went to the short cranks to help eliminate a massive toe overlap caused by riding a poorly designed bike with 700c wheels when she would have been so much better served with a bike with 650s. It was done strictly to eliminate the toe overlap of a poorly designed bike.

Hugh
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22 Feb 2013 21:04

sciguy wrote:[color="Black"]She[/color] went to the short cranks due to massive toe overlap caused by riding a bike with 700c wheels when she would have been so much better served with 650s. It was done strictly to eliminate the toe overlap.

Hugh
Really? Why isn't that a problem for everyone with 700c wheels? Especially those with even larger feet?

Anyhow, it just goes to show that shorter cranks are starting to gain a little acceptance. Glad to see she wasn't afraid to make a big change. It shows you how little bike manufacturers care about crank length because of what they supply. 140 is essentially the same ratio to 170 as a 48 frame is to a 58 frame. Most women are probably riding cranks that are way, way, too long for them.
Life is short, both reading my posts and training with PowerCranks will make it seem longer
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23 Feb 2013 00:02

FrankDay wrote:Anyhow, it just goes to show that shorter cranks are starting to gain a little acceptance. Glad to see she wasn't afraid to make a big change. It shows you how little bike manufacturers care about crank length because of what they supply. 140 is essentially the same ratio to 170 as a 48 frame is to a 58 frame. Most women are probably riding cranks that are way, way, too long for them.


Just another meaningless anecdote and not even related to cycling performance; more a safety decision.

We had the last training session before Canterbury Champs and all the riders are hitting PBs. Of course all things are not equal because it's an outdoor track, different day, some were wearing skinsuits and using aero helmets, others had race wheels in and some were not on the gear I asked them to ride.

But I no point did I see a rider and think: damn they would be faster on shorter cranks. Ditto watching World Track Champs this morning and NZ Elite TT champs for men and women.
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23 Feb 2013 01:30

FrankDay wrote:Another anecdotal report.

http://forum.slowtwitch.com/forum/Slowtwitch_Forums_C1/Triathlon_Forum_F1/140_cranks_-_not_bad_at_all_P4439838/

The remark I would make is he should probably be moving his seat back, not forwards. But, he will eventually figure this out if he stays with this.


Frank, if you will recall, I requested that you discontinue using anecdotes to bump the thread. I do not see that this one does anything except bump the circular, non-ending, and pointless joust that this thread has devolved to. No more anecdotal evidence.

This thread is supposed to be about crank length in general - you wrote the title. If you want to continually post anecdotes, such as this one, so long as they are not selling your product and are otherwise inside the forum rules, then you MAY do so, PROVIDED you start a thread titled "The importance of SHORT crank arm lengths to the cyclist" - or something equivalent. The science you guys quote is not definitive, and short cranks are a long way from being mainstream. I want these conversations to be valuable to all the forum users, not just a select few basically arguing off-topic.

For those readers who would like a more mainstream viewpoint, and advice, on crank length, I think you could start with Lennard Zinn. I do not agree with Lennard on everything, but he is a smart man with lots of experience at what he does, and he is definitely a mainstream expert opinion.

technical-faq-with-lennard-zinn-when-it-come-to-crankarm-length-no-easy-answers

technical-qa-with-lennard-zinn-a-question-of-crank-length

technical-faq-with-lennard-zinn-feedback-on-crank-length-chaingate-ii

This also goes for the "Pedaling Technique" thread. It has devolved into an exclusive discussion, not of pedaling technique, but of PowerCranks and their impact on pedaling technique. Since both threads have devolved into an exclusive conversation about these smaller topics, I will regard future continuation of these circular arguments as off-topic. If the threads continue to dwell on these points, I will close the threads, and you may open new ones that are more accurately titled.

I believe this is sufficient clarity.
It is of great use to the sailor to know the length of his line, though he cannot with it fathom all the depths of the ocean. ~ John Locke
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23 Feb 2013 02:43

hiero2 wrote:Frank, if you will recall, I requested that you discontinue using anecdotes to bump the thread. I do not see that this one does anything except bump the circular, non-ending, and pointless joust that this thread has devolved to. No more anecdotal evidence.

This thread is supposed to be about crank length in general - you wrote the title. If you want to continually post anecdotes, such as this one, so long as they are not selling your product and are otherwise inside the forum rules, then you MAY do so, PROVIDED you start a thread titled "The importance of SHORT crank arm lengths to the cyclist" - or something equivalent. The science you guys quote is not definitive, and short cranks are a long way from being mainstream. I want these conversations to be valuable to all the forum users, not just a select few basically arguing off-topic.

For those readers who would like a more mainstream viewpoint, and advice, on crank length, I think you could start with Lennard Zinn. I do not agree with Lennard on everything, but he is a smart man with lots of experience at what he does, and he is definitely a mainstream expert opinion.

technical-faq-with-lennard-zinn-when-it-come-to-crankarm-length-no-easy-answers

technical-qa-with-lennard-zinn-a-question-of-crank-length

technical-faq-with-lennard-zinn-feedback-on-crank-length-chaingate-ii

This also goes for the "Pedaling Technique" thread. It has devolved into an exclusive discussion, not of pedaling technique, but of PowerCranks and their impact on pedaling technique. Since both threads have devolved into an exclusive conversation about these smaller topics, I will regard future continuation of these circular arguments as off-topic. If the threads continue to dwell on these points, I will close the threads, and you may open new ones that are more accurately titled.

I believe this is sufficient clarity.
You ask for no more anecdotes and then post links to Zinn's OPINIONS about crank length. If you or anyone else can give me a scintilla of scientific evidence to support his views I (and the whole world) would love to see it. If anyone has a scintilla of scientific evidence to support any of the other formulas used to find best crank length please post it here. At least I have the Martin study to support that short cranks could be just fine and, perhaps, superior. Oh, and I have no problem at all if someone wants to come here and post arguments that longer cranks are better as long as they are prepared to back up their arguments.

Until then we are forced to discuss opinions and anecdotal evidence. If someone wins a major race on short cranks in the future (as has happened in the past), is that not acceptable to be mentioned? If someone does some testing comparing their own power on different length cranks, is that not acceptable to be mentioned? When I have the ability to measure pedal forces around the circle (hopefully soon) will it be unacceptable to post how pedal forces change as crank length changes? All of the above would be anecdotal evidence yet I think all would be germane to those interested in this discussion. As I said before, if forums restricted themselves to scientific evidence and forbade anecdotal evidence they would soon go the way of the gooney bird.

The last link I posted simply was to point out that someone, not in any way connected to me, tried what most would consider to be exceptionally short cranks and she didn't find them weird at all. Wouldn't surprise me at all to see her soon posting substantial improvements in performance. Are we forced to ignore that anecdotal evidence in this discussion if it occurs (it is a discussion isn't it?)?

This thread has no trouble staying on the front page mostly to the efforts of Fergie and Coapman. My efforts at providing new and fresh evidence to support my contention plays little role in this.
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23 Feb 2013 03:23

FrankDay wrote:At least I have the Martin study to support that short cranks could be just fine and, perhaps, superior. Oh, and I have no problem at all if someone wants to come here and post arguments that longer cranks are better as long as they are prepared to back up their arguments.


Only problem is that Martin would disagree with your opinion of the data.

Until then we are forced to discuss opinions and anecdotal evidence.


Not really, we can use the available data and the conclusions drawn and accept that crank length is not important.

If someone wins a major race on short cranks in the future (as has happened in the past), is that not acceptable to be mentioned?


Only if you can conclusively show that crank length positively contributed to their performance.

If someone does some testing comparing their own power on different length cranks, is that not acceptable to be mentioned?


Would be a big step up from supplying meaningless anecdotes.

When I have the ability to measure pedal forces around the circle (hopefully soon) will it be unacceptable to post how pedal forces change as crank length changes?


No, that would be actual data.

As I said before, if forums restricted themselves to scientific evidence and forbade anecdotal evidence they would soon go the way of the gooney bird.


Anecdotal evidence
From Wikipedia, the free encyclopedia

Look up anecdotal evidence in Wiktionary, the free dictionary.
See also: Confirmation bias and Cherry picking (fallacy)
The expression anecdotal evidence refers to evidence from anecdotes. Because of the small sample, there is a larger chance that it may be unreliable due to cherry-picked or otherwise non-representative samples of typical cases. Anecdotal evidence is considered dubious support of a claim; it is accepted only in lieu of more solid evidence. This is true regardless of the veracity of individual claims.


The last link I posted simply was to point out that someone, not in any way connected to me, tried what most would consider to be exceptionally short cranks and she didn't find them weird at all. Wouldn't surprise me at all to see her soon posting substantial improvements in performance. Are we forced to ignore that anecdotal evidence in this discussion if it occurs (it is a discussion isn't it?)?


I would ignore it because we have no comparison with her doing the same thing on a different crank length. Unless one believes they are acting as their own control:D

This thread has no trouble staying on the front page mostly to the efforts of Fergie and Coapman. My efforts at providing new and fresh evidence to support my contention plays little role in this.


There is nothing new and fresh to the stories added here. They add nothing to a claim of importance of crank length which really demands scientific analysis. This has been performed and the results rather nicely summarised by Martin in his presentation. No importance of crank length, unless you are seriously tall or seriously short and riding 170mm cranks.
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23 Feb 2013 04:08

CoachFergie wrote:Only problem is that Martin would disagree with your opinion of the data.
Actually, I don't think he would but since he isn't here I don't think either one of us should try to speak for him

When I have the ability to measure pedal forces around the circle (hopefully soon) will it be unacceptable to post how pedal forces change as crank length changes?

No, that would be actual data.
Fergie, not sure what constitutes "actual data" in your mind. Just to help you out here in understanding the difference between anecdotal data and scientific data (which is what I think we are talking about) I refer you to this article in Wikipedia Here is a quote from the article
Anecdotal evidence is considered the least certain type of scientific information.[15] It is the opposite of scientific evidence.[16] Researchers may use anecdotal evidence for suggesting new hypotheses, but never as validating evidence.


Anecdotal evidence is important when it leads people to investigate new areas and to the discovery of new knowledge. I believe that is what I am trying to foment here, awareness of this possibility that might lead to additional research in this area.
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