The importance of crank length to the cyclist.

[Martin318is]

I wasn't given a page number. Simply that he saw the article in the magazine. Maybe it was an old issue that he thought new because he commented the picture had Cadel in his Lotto kit.

This is likely to be the case. Coincidentally, I confirmed part of this with a training partner of Cadel's earlier this afternoon. Cadel has not used his powercranks in more than 2 years. He has since used a fixed gear bike in the off season instead - Aldo had previously said that there was no extra benefit using the powercrank over a fixie and the fixie was more generally practical.

 

[Alex Simmons/RST]

AFAIK, there are two "well known" aerodynamic principles at play here. frontal area and shape. Fairings increase frontal area but make up for it by such a good shape that overall drag is decreased. But, if shape remains essentially the same, reducing frontal area should reduce drag. So, I guess it is possible that one can reduce frontal area and increase drag, but that would not be expected if the only change is raising the seat since one wouldn't expect a dramatic change in shape.

That having been said, most of the riders I know who have made this change report being able to lower their handlebars from what they previously thought was the best they could do. Therefore, I would expect an even larger lowering of the frontal area to those who push the limits.

Going lower doesn't always improve aero. And it can end up reducing the power to drag ratio. That's why we measure these things, so we can be sure and not make WAGs and/or rely on folklore.

 

[oldborn]

It's already been done, scientifically, using high frequency data loggers For speed measurement (i.e. not an ordinary bike speed recorder), and that's possibly what Andy is referring to as demonstrating less precision.

Indoor coast down testing:
Candau et al. Med Sci Sports Exerc 1999; 31:1441-1447.

Outdoor coastdown testing:
Cameron. Human Power 1995; 12:7-11

Outdoor testing in particular showed a high Coefficient of Variation, certainly when compared to what's possible when field testing with a power meter.

Mate, it seems that PM gonna be used only for aerodynamics, which I admit is great. But you did not convince me to spend 2000 bucks on device which is same as HRM
Is it great tool yes, but not as that great, those Florida and SA dude find out.

 

[FrankDay]

This is likely to be the case. Coincidentally, I confirmed part of this with a training partner of Cadel's earlier this afternoon. Cadel has not used his powercranks in more than 2 years. He has since used a fixed gear bike in the off season instead - Aldo had previously said that there was no extra benefit using the powercrank over a fixie and the fixie was more generally practical.

In view of the restrictions you placed on some of the members here is there a reason you are bringing this off topic hearsay into this conversation?

 

[Martin318is]

In view of the restrictions you placed on some of the members here is there a reason you are bringing this off topic hearsay into this conversation?

its a topic heavily discussed in this thread and repeatedly reanimated by yourself. I thought you would be happy to receive updated information that was more solid than what you have.

 

[blutto]

Hey, hey wait a minute.
I found it very important to clarify things about insults and calling names here.
Long time ago I called Fargo: fat mediocracy, no name coach, realized that I cross the line.
I apologized to him twice PM. Never reply, so I think that guy who do not accept apologize is not very nice one.
On the other hand that same guy calling people liar, idiots, fools without even realizing that might hurt someone.
Putting Frank at even with Fargo is just unfair. When things get out control it is hard to be cool, but I did not saw Frank calling him names, did someone?

So I just call that guy Fargo, makes jokes about him, but never call him idiot, and apologize once again

So the question here is: Who is the guy here who really insults people?
IMHO, coach Fargo (even here he would be out of coach license) all the time.
I just do not care, but will never gave a kid coaching by sucha angry man, who do not accept apologize.

P.S. Not even in my wildest dreams, I did not tell someone how he should do mod job or criticise him Sorry to hijack thread once again

...couldn't agree more with your assessment of our dear friend...( and just think of all the cycliing careers this man has ruined...and we all know that given the attitude he has displayed here that has happened...and probably repeatedly)

...and if I could add one point....

....I find it supremely ironic that our dear friend is acting just like those wonderful scientists who used their carefully crafted peer reviewed studies to beat Arthur Lydiard over the head for all those years....and he is apparently a self-professed Lydiard fan...

...and just to add one more thought....from where I'm sitting our dear friend is actually much worse than those wonderful scientists because given his knowledge of what happened to Lydiard he should know better...but evidently he hasn't thought that thru and that unfortunately undercuts everything he purports to be fighting for( which in the broad sense is supposed to be science and the method it is based on)...in fact I really feel that at the base level he is not fighting for anything, he is just fighting( and in so doing acting like the most common garden variety fundamentalist)... and thru his paticipation this, and other related threads, have suffered mightily for it...

Cheers

blutto

Cheers

blutto

 

[oldborn]

You my friend, Mr. Boeing and I are on Fargo ignore list.
But guess what, we are not, he is watching us all the time (we are on his favorite users list)

Let me explain, yesterday I started a thread about Power meters, after 30 minutes or so (time do not lie) Fargo copied mine link to the study and idea to his self adoring thread and said: "I just saw this paper" without even mention form where he copy-paste this idea and study.
I mean I can charge the man for intellectual property thing

Is not this funny for a serious coach like Fargo
That is how this dude is messed up

P.S. Dear Martin, sorry to hijack this thread once again, but I found important/funny to say this.

 

[CoachFergie]

Going lower doesn't always improve aero. And it can end up reducing the power to drag ratio. That's why we measure these things, so we can be sure and not make WAGs and/or rely on folklore.

I wonder what the numbers would say if we took into account airflow through the moving body and through the bicycle and how that would compare with a cyclist in a pod in normal racing position.

Cadel on a fixxie, so old school, love it!

 

[FrankDay]

its a topic heavily discussed in this thread and repeatedly reanimated by yourself. I thought you would be happy to receive updated information that was more solid than what you have.

Ugh, I wasn't particularly happy to hear unattributed hearsay information that supports your bias and drops the poor departed A. Sassi into the mix purporting to express his negative opinion (coming from a moderator no less). Unattributed hearsay gossip is hardly "more solid" in my book. (I would be a little surprised if that was Sassi's actual opinion on the product - impossible to confirm now - as we have gotten a large number of pro's on the cranks through his Mapei center, including two time Olympic gold medalist P. Bettini). But, you and others get mad at me for simply pointing out there is little basis for these criticisms from those who have never used them. Now if Cadel himself had come here and said "I used them for 8 years and all that stuff in my book and that article is hogwash so I stopped using them two years ago" that would be a different story and I would have to deal with it. But, he has not.

The PowerCranks did make Cadel's book and they did seem to make this article with a picture (whenever it was). Oh, and there are actually a couple of scientific studies that show some benefit to them, more than the PM can say. That is pretty solid in my book. So, as it concerns my product, can we stick with verifiable facts or label opinions as opinions and move on.

 

[CoachFergie]

Oh, and there are actually a couple of scientific studies that show some benefit to them, more than the PM can say. That is pretty solid in my book. So, as it concerns my product, can we stick with verifiable facts or label opinions as opinions and move on.

I wasn't aware of any studies that showed a benefit to independent cranks. Can you please point me in the right direction. They would have to be compared against papers like Sperlich et al (2010) that found no difference in performance within a time period where similar training intervention studies found substantial differences in performance (Burgomaster et al, 2006).

There are several studies published in the sports medicine and applied physiology literature that show that a power meter does indeed measure power. Gardner et al (2004) would be a good start.

The majority of research on training methods and dietary practice's for cyclists use wattage as a performance metric. Poorly conducted research that confuses looking at either a number on a power meter or a number on a heart rate monitor with an actual training method add nothing to the debate.

 

[Martin318is]

Ugh, I wasn't particularly happy to hear unattributed hearsay information that supports your bias and drops the poor departed A. Sassi into the mix purporting to express his negative opinion (coming from a moderator no less). Unattributed hearsay gossip is hardly "more solid" in my book. (I would be a little surprised if that was Sassi's actual opinion on the product - impossible to confirm now - as we have gotten a large number of pro's on the cranks through his Mapei center, including two time Olympic gold medalist P. Bettini). But, you and others get mad at me for simply pointing out there is little basis for these criticisms from those who have never used them. Now if Cadel himself had come here and said "I used them for 8 years and all that stuff in my book and that article is hogwash so I stopped using them two years ago" that would be a different story and I would have to deal with it. But, he has not.

True, Cadel hasn't. I am just operating to the standard that you have very clearly set in this thread. Someone he rides with told me this. From the point of view of the reader of this thread, there is little significant difference between my presenting this earlier post (without any accompanying histrionics you might notice - just a bland offering of information) and your earlier statements such as a younger rider telling you that Cadel recommended the equipment to him. It is certainly more relevant than you making assumptions based upon photos printed in magazines that are clearly so old that the team kit is from at least 2 years ago.

My use of 'this is likely to be the case' incidentally, was purely regarding the age of the photo if Cadel was in Lotto kit.

The PowerCranks did make Cadel's book and they did seem to make this article with a picture (whenever it was). Oh, and there are actually a couple of scientific studies that show some benefit to them, more than the PM can say. That is pretty solid in my book. So, as it concerns my product, can we stick with verifiable facts or label opinions as opinions and move on.

I truly, deeply, don't understand why you continue to bring this into the conversation. You could just as easily have said, 'more than healing crystals can say' as there is just as little relevance to PowerCranks.

Once again though, this is irrelevant. I presented what I believe to be fact due to its source and you are rejecting it in favour of some old photos and no current information. You are now attacking me (a moderator no less ) for what you have repeatedly done in this thread. Its up to you what you do as a businessman but from where I stand, invoking Cadel's name to support your product when you have so little contact with him that you don't know if he actually uses it anymore is not something I would do. In your position I would contact him and get myself more up to date - especially from an R&D perspective.

 

[FrankDay]

I wasn't aware of any studies that showed a benefit to independent cranks. Can you please point me in the right direction. They would have to be compared against papers like Sperlich et al (2010) that found no difference in performance within a time period where similar training intervention studies found substantial differences in performance (Burgomaster et al, 2006).

You most certainly are aware of those studies because we have discussed them many times, but thanks for the opportunity of mentioning them again.

Lutrell showed a statistically significant 10% increase in cycling efficiency in "trained" cyclists after 6 weeks (18 1 hr sessions) of PowerCranks training compared to regular cranks.

Dixon showed a statistically significant 15% increase in VO2max and an 11% increase in max power after 6 weeks of immersion training

Fernandez-Pena and Nuckles both showed pedaling coordination changed in 6 weeks.

I don't deny that there are studies that fail to show benefit. One must indeed compare these studies to see if one can figure out why some show benefit and some don't. But, my statement was only that there are at least some studies that show PC's have a benefit compared to the PM, which has no positive studies and two that show no benefit.

 

[CoachFergie]

Lutrellshowed a statistically significant 10% increase in cycling efficiency in "trained" cyclists after 6 weeks (18 1 hr sessions) of PowerCranks training compared to regular cranks.

Study didn't measure performance so no evidence of a benefit.

Dixon showed a statistically significant 15% increase in VO2max and an 11% increase in max power after 6 weeks of immersion training

Not a published study. No control group to compare with other methods of performance enhancement.

Fernandez-Pena and Nuckles both showed pedaling coordination changed in 6 weeks.

Neither showed a improvement in performance.

I don't deny that there are studies that fail to show benefit. One must indeed compare these studies to see if one can figure out why some show benefit and some don't.

None of the published studies showed a performance enhancement. But nice to see agreement that 6 weeks is sufficient time to see a physiological change. There is considerable data that one can see physiological and performance improvements in a far shorter time with a far less training stimulus (Burgomaster and Gibala's short interval training studies).

But, my statement was only that there are at least some studies that show PC's have a benefit compared to the PM, which has no positive studies and two that show no benefit.

I am confused to why someone would expect a benefit from racing and training with a power meter when it is a measurement tool. Don't the physiological performance adaptations come from the training and dietary interventions. I use a power meter to measure those interventions.

 

[FrankDay]

True, Cadel hasn't. I am just operating to the standard that you have very clearly set in this thread.

This thread was started as a thread about crank length and its affects on cyclists. Since I started it based upon some thought experiments and anecdotal reports I was forced to rely upon musings and reports of others to simply raise the topic.

It seems a bit of a stretch to me after you specifically told me to not wonder off topic, for you to go back to one of these off topic meanderings and give an anecdotal hearsay report that superficially supports my previous post but really backhandedly bashes my product.

There are plenty of PowerCranks threads. Why does the topic seemingly have to dominate every thread where I happen to have a contrary opinion/thought to the majority view. Fergie has been bad enough. Seems like a forum monitor could show a little more restraint.

 

[CoachFergie]

This thread was started as a thread about crank length and its affects on cyclists. Since I started it based upon some thought experiments and anecdotal reports I was forced to rely upon musings and reports of others to simply raise the topic.

There has been no evidence provided that changing crank lengths has any affect on performance, efficiency or aerodynamics unless one goes to extremes then the research and experience of coaches suggest that it costs performance.

 

[Martin318is]

This thread was started as a thread about crank length and its affects on cyclists. Since I started it based upon some thought experiments and anecdotal reports I was forced to rely upon musings and reports of others to simply raise the topic.

It seems a bit of a stretch to me after you specifically told me to not wonder off topic, for you to go back to one of these off topic meanderings and give an anecdotal hearsay report that superficially supports my previous post but really backhandedly bashes my product.

There are plenty of PowerCranks threads. Why does the topic seemingly have to dominate every thread where I happen to have a contrary opinion/thought to the majority view. Fergie has been bad enough. Seems like a forum monitor could show a little more restraint.

Frank, put simply, I was providing reliable information that was able to put an end to one branch unanswered of this discussion. I am sorry that you do not like the information but I cannot be held responsible for that. Frankly, how it reflects upon you and your product is determined much more by how you use it than by the information itself. It was not my intent to 'bash your product' as evidenced by the lack of any added interpretation from myself. I also did not open any further line of inquiry 'off the topic'. I merely passed on a piece of information that I had received that day that was pertinent to an earlier part of the conversation (which still appears on the same page as this one). You may consider it to be off topic, however as it was closing a line of conversation rather than opening one, it is normal practise here to allow that.

If you wish to make this issue personal with me then that is a different story. You will note first however that there continues to be nothing negative about your or your product in this post.

 

[CoachFergie]

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.

And, in general, we are talking substantially shorter than what most would consider to be a short crank. Our data suggests that around 100 mm crank length would be near optimum for most. I am currently riding 105 mm cranks with good feeling.

I believe there are good reasons that explain the above benefits and we can discuss them if any desire.

If possible I would like to open an actual discussion of this issue based on facts and data rather than bias and opinion.

This is the OP where it is claimed that short cranks will improve power for most and allow improved aerodynamics without a loss of power. The hypothesis is that changing crank length will affect power output. Crank length is what we manipulate and power is the dependant variable we measure to see if any change has taken place.

My observation is that the power meter will have no influence on the change in crank length. This is at odds with the strawman claims being made in another thread that a power meter should improve performance.

Just as no data has been presented that bolting a pair of shorter cranks significantly improves power (Martin's study) or improves efficiency (McDaniel) there is no data out there that shows that a power meter pedals the bike for you.

Asking how much gain one can expect from racing and training with a power meter is another strawman argument as the role of a power meter is to measure performance. Training and dietary interventions are where the physiological performance gains potentially come from.

Seeing Cadel Evans success in the Tour de France this year I am quite inspired to run a study that compares two groups, one training on a fixed wheel bicycle and the other using a freewheel.

 

[blutto]

....as this thread stumbles along and loses any chance of actually being in any way shape or form helpful ( beyond of course showing the world what an absolute genius Fargo is ) a thought occurred to me that may help re-focus our efforts here...

...in rummaging thru an older thread I ran across the following...

Maybe his saddle was too high. I had one of my out of town riders come up and watched him race as he was having similar issues. We put his saddle down 5mm and problem was solved.

As I said previously most issues with pedalling technique are solved by getting the position right on the bike

. ...could one see the changing of the circumference of the pedalling circle as simply another aspect of the various issues that have to addressed in order to achieve good position...and if one accepts that premise it is actually difficult to accept that changing crank-arm length could not potentially affect power output in a positive way...it could be then said that crank-arm length is simply another variable to manipulate in the attempt to find an optimum position...now granted it may not guarantee more power in all instances but to dismiss it out of hand may be considered by some to be quite juvenile....

...so are there any thoughts about how that variable can be applied to achieve an optimum power output ( and not necessarily related only to test bed analysis but more to real world conditions....where such items as aero and comfort criterions may be important variables...).... as say we apply certain agreed upon ideas to other parts of the fitting process...for instance, how does leg-length play into this...is reach affected and does that affect the efficiency of the upper-body musculature...etc...etc....

Cheers

blutto

 

[FrankDay]

....as this thread stumbles along and loses any chance of actually being in any way shape or form helpful ( beyond of course showing the world what an absolute genius Fargo is ) a thought occurred to me that may help re-focus our efforts here...

...in rummaging thru an older thread I ran across the following...

Maybe his saddle was too high. I had one of my out of town riders come up and watched him race as he was having similar issues. We put his saddle down 5mm and problem was solved.

As I said previously most issues with pedalling technique are solved by getting the position right on the bike

. ...could one see the changing of the circumference of the pedalling circle as simply another aspect of the various issues that have to addressed in order to achieve good position...and if one accepts that premise it is actually difficult to accept that changing crank-arm length could not potentially affect power output in a positive way...it could be then said that crank-arm length is simply another variable to manipulate in the attempt to find an optimum position...now granted it may not guarantee more power in all instances but to dismiss it out of hand may be considered by some to be quite juvenile....

...so are there any thoughts about how that variable can be applied to achieve an optimum power output ( and not necessarily related only to test bed analysis but more to real world conditions....where such items as aero and comfort criterions may be important variables...).... as say we apply certain agreed upon ideas to other parts of the fitting process...for instance, how does leg-length play into this...is reach affected and does that affect the efficiency of the upper-body musculature...etc...etc....

Cheers

blutto

Two "real world" scenarios that almost everyone will be familiar with I think illustrate a bit of what I am trying to convey.

1. How people choose to use the stairmaster. A stairmaster allows the user to freely choose how high they lift the foot for each step and freely choose their cadence. A Stairmaster is also an entirely pushing machine. Almost everyone on an "endurance climb" will be taking about 6 inch steps. It seems the body freely chooses this relatively small range of motion compared to the ROM forced on the leg by the typical bicycle crank. Why is this? Well, I think it is because the knee looses leverage and efficiency if it bends too much. Therefore, if given the chance the body keeps the joint ROM within certain limits to maximize muscle efficiency.

2. Weight lifting. People can lift much more weight doing a half-squat than when doing a full squat. Why? Same explanation as above I think.

Hopefully, we will stay on track.

 

[Martin318is]

Question: Wouldn't restricting a muscle to a smaller range of contraction ultimately result in a larger risk of problems on longer sessions or over many sessions?

Describing it the way you just did I immediately started to wonder whether the muscle would be more likely to cramp etc than a muscle that is worked through a larger range of motion. Have you had any thoughts on that Frank? Is it a reasonable idea or have you discounted it?

I know personally from my rockclimbing days that I have had huge problems when movements have been restricted such that muscles were working in small ranges (such as long sections of smearing on steep faces). I would experience the 'sewing machine' in my calves and eventually cramp.

 

[Martin318is]

Question two:
If circulation is assisted by the motion of the legs, what happens to this assistance when the range of movement of the leg is restricted? Is it impacted by using a shorted crank with its smaller range of movement?

 

[FrankDay]

Question: Wouldn't restricting a muscle to a smaller range of contraction ultimately result in a larger risk of problems on longer sessions or over many sessions?

I guess that is possible but I can't think of a physiologic reason as to why that would occur. Those who have gone this way, including me for over a year, haven't seen any issues that I know of.

Describing it the way you just did I immediately started to wonder whether the muscle would be more likely to cramp etc than a muscle that is worked through a larger range of motion. Have you had any thoughts on that Frank? Is it a reasonable idea or have you discounted it?

Again, I am not aware of any physiological reason this should happen. It is not something people have reported but our numbers are small. Do people whose primary exercise regimen is on the stairmaster have more muscle cramp issues? I don't know but I doubt it.

I know personally from my rockclimbing days that I have had huge problems when movements have been restricted such that muscles were working in small ranges (such as long sections of smearing on steep faces). I would experience the 'sewing machine' in my calves and eventually cramp.

Now, I think you are talking isometric contractions. Muscles need to regularly relax for long enough for blood to come in delivering oxygen and taking away waste. If one has to bring the cadence up so high that blood flow is restricted then this could be an issue. But, this isn't an issue yet. Drew, who did the everest challenge on 110 mm cranks told me his preferred cadence is in the 80's now. He will be doing furnace creek 508 next weekend (508 miles with over 30k ft of climbing). We might find out if cramping is an issue then, at least with one person who is at the extreme end of the bell curve.

 

[FrankDay]

Question two:
If circulation is assisted by the motion of the legs, what happens to this assistance when the range of movement of the leg is restricted? Is it impacted by using a shorted crank with its smaller range of movement?

Circulation is enhanced by the contraction of muscles pushing blood out of the muscles and into the veins. I would expect this to be unaffected by ROM since the amount of blood in the muscle is related to how much work it is doing.

 

[Martin318is]

Now, I think you are talking isometric contractions. Muscles need to regularly relax for long enough for blood to come in delivering oxygen and taking away waste. If one has to bring the cadence up so high that blood flow is restricted then this could be an issue. But, this isn't an issue yet. Drew, who did the everest challenge on 110 mm cranks told me his preferred cadence is in the 80's now. He will be doing furnace creek 508 next weekend (508 miles with over 30k ft of climbing). We might find out if cramping is an issue then, at least with one person who is at the extreme end of the bell curve.

yes, I was thinking the same when I wrote that bit but what was in my head was more around the way that when someone does something with a restricted range of motion they start to crave the ability to step out of that position and stretch etc. I guess that a higher cadence (however, an 80 cadence is low!) would help with this. For me though, an 80 cadence is very low. I ride at around 95-110 so a shortening of cranks would likely (I guess?) end up in me riding up to 120 on average....

My max cadence on a 172.5 crank is upwards of 195rpm usually (varies based upon fatigue etc)

 

[Martin318is]

Circulation is enhanced by the contraction of muscles pushing blood out of the muscles and into the veins. I would expect this to be unaffected by ROM since the amount of blood in the muscle is related to how much work it is doing.

but the 'pumping' effect of the muscle would be smaller with a smaller range of motions surely?