The importance of crank length to the cyclist.

[FrankDay]

A new anecdotal report: A local long-time PowerCranker had a problem with his PowerCranks and he came by the office to get it fixed. He has had his PowerCranks for 8 years and has over 100,000 miles on them. We think his is pretty well adapted (He said it took him 18 months to get fully adapted - so much for those 6 week studies). We fixed his issue and then talked to him about trying shorter cranks. It took a lot of talking (he simply couldn't believe shorter could be better) but we convinced him to try a week at 150 and report back, so we set him up and he rode off on 150 cranks. He emailed when he got home that he already loved the 150's as being so much easier on the HF's, especially in the aero position. The real test will be when he climbs Mt Diablo. He is now ready to experiment with 130's. I will let you know what he further reports.

 

[CoachFergie]

A new anecdotal report: A local long-time PowerCranker had a problem with his PowerCranks and he came by the office to get it fixed. He has had his PowerCranks for 8 years and has over 100,000 miles on them. We think his is pretty well adapted (He said it took him 18 months to get fully adapted - so much for those 6 week studies). We fixed his issue and then talked to him about trying shorter cranks. It took a lot of talking (he simply couldn't believe shorter could be better) but we convinced him to try a week at 150 and report back, so we set him up and he rode off on 150 cranks. He emailed when he got home that he already loved the 150's as being so much easier on the HF's, especially in the aero position. The real test will be when he climbs Mt Diablo. He is now ready to experiment with 130's. I will let you know what he further reports.

So what part of that advertorial (aka spam) is meant to provide evidence that crank length is important?

Saying that riders I coach won 21 titles at the Canterbury Track Cycling champs and I attribute it to not paying attention to crank length is just as meaningful a statement.

 

[coapman]

(He said it took him 18 months to get fully adapted - so much for those 6 week studies). We fixed his issue and then talked to him about trying shorter cranks. It took a lot of talking (he simply couldn't believe shorter could be better) but we convinced him to try a week at 150 and report back, so we set him up and he rode off on 150 cranks. He emailed when he got home that he already loved the 150's as being so much easier on the HF's, especially in the aero position.

When a rider is fully adapted after that 18 months of exclusive PC use, where in the pedaling circle can the PC advantage be found, where does he gain that extra 40% crank torque.

 

[FrankDay]

When a rider is fully adapted after that 18 months of exclusive PC use, where in the pedaling circle can the PC advantage be found, where does he gain that extra 40% crank torque.

The advantage, I believe, occurs at every point around the circle. From making the muscle forces more tangential, to increasing forces across the top and bottom, to increasing the unweighting on the backstroke. It isn't one thing, it is lots of small things that add together to become a big thing.

 

[hiero2]

You know, if a thread is to be locked "in the name of science" you would only be able to discuss pretty much nothing. . . .

Anyhow, I am somewhat appalled that you, as a moderator, would even consider this request based upon the science. These threads would be much better (I doubt we would be above 100 posts and off the front page a long time ago) if you would simply ban those who only know how to respond with personal attacks. Where is the science there?

. . .Your consideration of this is especially troubling in view of the fact that I have been told that several of the "big boys" either are manufacturing shorter cranks now (Rotor) or expect to soon be manufacturing shorter cranks. Something must be making them do this but, I suspect, it sure as heck is not the naysayers who hang out here. Will you still ban crank length discussions when Shimano starts making 150 mm cranks? Or, is it only my input that is troubling?

No, the question isn't "science" at all. The question is simply this "Is this forum being used to promote or sell a product where the poster has a personal (and financial) interest in selling that product." You are the main poster in two threads, both of which are now more about your product and theories then they are about the thread title. I could, I suppose, close the threads because they have gone hopelessly off-topic. Oddly enough, the other thread you started ("Pedaling technique"), you began with a post where you were correct in saying that the significance was far greater than for just your product. But, that thread degenerated into what is primarily a discussion of your theories and product. And using the forum to spam for a product is, last time I checked, in violation of the TOS.

These two threads are borderline in my thinking at this moment. I am not yet convinced that they are in violation of the TOS.

As for being "appalled" that I would take what a poster says into consideration, would you rather I acted out-of-hand, in a dictatorial fashion? I take everything into consideration - some things get more consideration than others - depending on the credibility of the source, and the reasoning offered. That includes what you have to say.

 

[CoachFergie]

These two threads are borderline in my thinking at this moment. I am not yet convinced that they are in violation of the TOS.

Both threads start with a little advertorial leading to a link on his commercial site. Smells like SPAM to me. Frank has been banned from other sites like Slowtwitch for doing this.

 

[FitSsikS]

Let me be Frank:
Click > Xtri (your source for triathlon news and content) Chats With Power Cranks Inventor Frank Day

 

[FrankDay]

As for being "appalled" that I would take what a poster says into consideration, would you rather I acted out-of-hand, in a dictatorial fashion?

Does anyone ever read and understand what I actually write? The original request by fortysixandtwo was the thread be locked "in the name of science" and you responded as "having a similar thought". Anyhow, back in post 1766 of this thread this is what I said: "Anyhow, I am somewhat appalled that you, as a moderator, would even consider this request based upon the science." In fact, I am probably the only poster who has actually brought science into this discussion as it was a scientific study (Martin) that got me thinking about this subject.

 

[FrankDay]

Frank has been banned from other sites like Slowtwitch for doing this.

Really? News to me.

 

[CoachFergie]

In fact, I am probably the only poster who has actually brought science into this discussion as it was a scientific study (Martin) that got me thinking about this subject.

Hilarious. 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.

 

[CoachFergie]

Really? News to me.

Ha ha, so you voluntarily stopped starting SPAM threads on Slowtwitch

 

[sciguy]

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

 

[FrankDay]

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.

 

[FrankDay]

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.

 

[CoachFergie]

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?

 

[CoachFergie]

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.

 

[FrankDay]

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.

 

[FrankDay]

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.

 

[CoachFergie]

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.

 

[CoachFergie]

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.

 

[FrankDay]

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.

 

[FrankDay]

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.

 

[CoachFergie]

How does this contribute to the debate about your claimed importance of crank length?

 

[sciguy]

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.

She 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

 

[FrankDay]

She 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.