The importance of crank length to the cyclist.

[CoachFergie]

The highlighted part is a possibility. That's where subtle, individual changes come into play and most forum lurkers are looking for measurable proof that radical departures actually work before wrecking their clients' position. You should offer up some research product to Fergie and others with some incentives to prove your point. Convincing tri-athletes to spend ridiculous money for radical measures isn't proof.

There are adjustable crank length cranks available to me here in Christchurch but I would just be replicating Martin, McDaniel and others work.

WRT aerodynamics there are many other (free and easy) options to try before one drops a bundle on shorter cranks, lifting the seat, shunting it back, lifting the bars and shortening the stem.

 

[FrankDay]

There are adjustable crank length cranks available to me here in Christchurch but I would just be replicating Martin, McDaniel and others work.

You would only be replicating their work if you reproduced their protocol and submitted it for publication. Seeing how it works for you is not replicating their work.

WRT aerodynamics there are many other (free and easy) options to try before one drops a bundle on shorter cranks, lifting the seat, shunting it back, lifting the bars and shortening the stem.

What is your issue with adding something else to the list of things that someone might try, even if it might cost something (similar to, say, replacing the stem), if they are trying to optimize their aerodynamics? Really, what is your concern here with this discussion?

 

[CoachFergie]

You would only be replicating their work if you reproduced their protocol and submitted it for publication. Seeing how it works for you is not replicating their work.

Everyone has limited time and money so when choosing which of the many performance enhancing variables you wish to experiment with it pays to choose some with more than a 1% chance of an improvement. While I would not expect a 100% performance improvement like Burgomaster et al found it would certainly guide the direction I choose.

What is your issue with adding something else to the list of things that someone might try, even if it might cost something (similar to, say, replacing the stem), if they are trying to optimize their aerodynamics? Really, what is your concern here with this discussion?

Time and money. Time that could be spent chasing real gains and money that could be spent on getting more racing or better diet or if really wanting to test each training, diet, racing, recovery, technique, tactical experiment then more wind tunnel time and a power meter.

 

[FrankDay]

Time and money. Time that could be spent chasing real gains and money that could be spent on getting more racing or better diet or if really wanting to test each training, diet, racing, recovery, technique, tactical experiment then more wind tunnel time and a power meter.

Let me get this straight. I start a thread to discuss the potential advantages to consider trying shorter cranks and you think that readers could better spend their time and money considering:

1. better diet. Perhaps you have a study that shows this is a reliable way to improve and what the best diet is to accomplish this.

2. recovery technique. Perhaps you have a study that shows this is a reliable way to improve and what the best recovery technique is to accomplish this.

3. tactical experiment. Perhaps you have a study that shows this is a reliable way to improve and what the best teactical experiment is to accomplish this.

4. "more" wind tunnel time. As if most of the people here have had any wind tunnel time. Perhaps you have a study that shows this is a reliable way to improve and how much wind tunnel time is required to accomplish this. Oh, and how much does this cost compared to, say, $50 for a pair of internet shorter cranks.

5. A power meter. Perhaps you have a study that shows this is a reliable way to improve in view of the fact that the only study on this device that I am aware of shows no benefit to using the device compared to not using one. Since the cost of most of these devices is over $1,000 how does this fit in your time and money explanation.

Time and money indeed.

We all know you have your bias's but it really is possible that open discussions on internet forums might cause others to reach other conclusions. But, it is hard to have an open discussion if every time someone posts an alternative view to yours you call them stupid.

 

[CoachFergie]

Let me get this straight. I start a thread to discuss the potential advantages to consider trying shorter cranks and you think that readers could better spend their time and money considering:

1. better diet. Perhaps you have a study that shows this is a reliable way to improve and what the best diet is to accomplish this.

Plenty of research to support this contention. Where would you like me to start.

2. recovery technique. Perhaps you have a study that shows this is a reliable way to improve and what the best recovery technique is to accomplish this.

A bit like pedalling technique, crank length, cleat position and so forth the research in this area allows people to separate the good from the bad. Massage, compression clothing, ice baths etc have no physiological basis.

3. tactical experiment. Perhaps you have a study that shows this is a reliable way to improve and what the best teactical experiment is to accomplish this.

Again serves more as a warning when assessing power data from races. Vogt et al (2006) studied riders power from the Tour de France and suggested that tactical and team considerations could confound the results.

4. "more" wind tunnel time. As if most of the people here have had any wind tunnel time. Perhaps you have a study that shows this is a reliable way to improve and how much wind tunnel time is required to accomplish this. Oh, and how much does this cost compared to, say, $50 for a pair of internet shorter cranks.

Seeing improvements in power delivery and metabolic efficiency are non significant you were the one who raised aerodynamic advantage. How else would you measure any improvement with a wind tunnel or a power meter and the Chung test. A road based TT will always be confounded by the weather.

5. A power meter. Perhaps you have a study that shows this is a reliable way to improve in view of the fact that the only study on this device that I am aware of shows no benefit to using the device compared to not using one. Since the cost of most of these devices is over $1,000 how does this fit in your time and money explanation.

Staggers me that people confuse a tool that measures performance as opposed to a training method, dietary strategy or piece of equipment that intends to improve performance.

Swart's study compared performance looking at one number compared to looking at another and found no difference. Not very surprising. He might have well as compared a training session watching Simpsons verses watching Family Guy.

Time and money indeed.

I have never told anyone I won't coach them without a power meter. If I had any sense I would tell them to steer clear of PMs because any claim I make is now easily tested.

We all know you have your bias's but it really is possible that open discussions on internet forums might cause others to reach other conclusions. But, it is hard to have an open discussion if every time someone posts an alternative view to yours you call them stupid.

The issue is claims made with poor evidence (anecdotes, or poorly designed experiments).

The science tells us that there are no significant benefits in terms of power delivery or efficiency despite claims to the contrary.

 

[Boeing]

coachfargo, always telling us his crank is longer than ours

 

[lostintime]

Everyone decides what's best for themselves .... and since no tow of us are alike . . . that leaves a huge range of options. If some says X length of crank arms works for them . . . . great! I see people loving 200mm as well 150mm cranks. . .. who am I or anyone else to question them since I am not living in their body. DOH!

We all seem to get this idea we know what's best for another, as most of grew up with people telling us what was best for us. We just unconsciously continue it. I have no doubt a person could thrive on using 175mm cranks and say ... 140mm ones. The limiting factor is 99.9% between the ears .

We can study crank length or anything else all day every day until the cows come home ( a forever wait) . . . . . but they will never figure out how we work within. . . . because we're ever evolving . . . ever changing. What was best yesterday isn't best today. That's the beauty of being alive

 

[FrankDay]

Here is an interesting link that goes to this topic. Pay particular attention to the discussion about the hour record between about 3:30 and 5 minutes in.

http://www.youtube.com/watch?NR=1&v=PfQNnrrsO9s

All of the technological innovation in bicycles and training (including power meters, composite materials, diet, recovery, etc.) over the years didn't result in much improvement. If you want to get faster pay attention to aerodyanmics. And, while this is a video put on by a wheel manufacturer, the absolute biggest source of drag is the rider himself.

 

[CoachFergie]

Everyone decides what's best for themselves .... and since no tow of us are alike

http://www.thetech.org/genetics/ask.php?id=32

We are more alike than we are different. The differences are the environments we are in.

. . . that leaves a huge range of options. If some says X length of crank arms works for them . . . . great! I see people loving 200mm as well 150mm cranks. . .. who am I or anyone else to question them since I am not living in their body. DOH!

How does this resolve the issue of what our first move is. Do I set my crank length because rider X does it or because a study looked at a group of people and determined a formula that gets us closer to the point.

Or do we have to personally experiment with crank length, starting from scratch each time. How long should this experiment take. Will I know a certain crank length works for me in 1 day, 1 week, 1 month, 1 year?

And while I am experimenting with crank length does this process of determining crank length not dictate that I must follow the same procedure for cleat placement, seat height, saddle tilt, angle of foot on the pedal, set back of the saddle, shape of the saddle, cadence and all the other 10,000 factors that contribute to cycling performance.

So while experimenting with crank length how do I control for the other little experiments that I need to do to determine how my individual differences can be optimised?

 

[CoachFergie]

Here is an interesting link that goes to this topic. Pay particular attention to the discussion about the hour record between about 3:30 and 5 minutes in.

http://www.youtube.com/watch?NR=1&v=PfQNnrrsO9s

All of the technological innovation in bicycles and training (including power meters, composite materials, diet, recovery, etc.) over the years didn't result in much improvement. If you want to get faster pay attention to aerodyanmics. And, while this is a video put on by a wheel manufacturer, the absolute biggest source of drag is the rider himself.

Some of us figured that out when Chris Boardman added 6km to Eddy Merckx's world hour record in 1996 using the Superman position and when forced to use the same bike as Eddy only added 10 metres.

Well actually before then as the science of aerodynamics is pretty well established.

 

[FrankDay]

So while experimenting with crank length how do I control for the other little experiments that I need to do to determine how my individual differences can be optimised?

Well, Fergie, that is why you are being paid the big bucks. To figure out how to do just that. One fellow who did, at least, try to see what he could do making the short crank change came up with the following improvements. Of course, he does a lot of aero work so maybe he knows what he is doing.

Your results may differ.

 

[CoachFergie]

There is a difference between what someone claims in an cycling mag or site like Pez and what would get published in a scientific journal. In a scientific forum Cobb would have to show how he arrived at that figure, what measures he used and how he controlled for 3rd variables.

 

[FrankDay]

Well actually before then as the science of aerodynamics is pretty well established.

Ugh, yes. and one of the major factors that affect overall drag is frontal area. Anyhow, one area of bike design that the UCI does not regulate is crank length. Seems there might be some improvements available there that, if I were serious about breaking that record, ought to be, at least, investigated. But, not by you since you have told us it is just too much trouble. Rather work on diet. Maybe Boardman should have worked on his diet and he maybe could have gotten to 15 meters.

 

[CoachFergie]

Ugh, yes. and one of the major factors that affect overall drag is frontal area. Anyhow, one area of bike design that the UCI does not regulate is crank length. Seems there might be some improvements available there that, if I were serious about breaking that record, ought to be, at least, investigated. But, not by you since you have told us it is just too much trouble. Rather work on diet. Maybe Boardman should have worked on his diet and he maybe could have gotten to 15 meters.

Boardman was one of the most aerodynamic riders out there. His power for the 1996 Hour record was well below the power Merckx put out for 60min in a lab test in Belgium after he broke the Hour record in Mexico.

Too much trouble?

Well if we are experimenting with crank length then we have to take the following into account...

* How long do we test? Some would claim it takes 3-9 months to see a change in improvement.

* We should test one item at a time? Some would claim we need to "exclusively" use one position or one piece of equipment.

* How do we control for confounding variables? Training, diet, recovery, weather, motivation etc could have affected the result. How do we "control" for those factors?

* How do we compare this method of lowering frontal area with other methods? There are other ways to change body position on the bike and the reason I test riders in the wind tunnel with a power meter is because the best position may not be optimal for power delivery.

* What about opportunity cost? While performing this 3-9month experiment manipulating one variable exclusively we are missing the opportunity to conduct other experiments. 100% improvement in a short term test to exhaustion from 2 weeks of SIT training. That's 12 minutes of training stimulus. Now we know that people don't do tests to exhaustion in competition but if we are experimentering (sic) for performance gains a proven 100% is better than a claimed 30%.

 

[Alex Simmons/RST]

Here is an interesting link that goes to this topic. Pay particular attention to the discussion about the hour record between about 3:30 and 5 minutes in.

http://www.youtube.com/watch?NR=1&v=PfQNnrrsO9s

All of the technological innovation in bicycles and training (including power meters, composite materials, diet, recovery, etc.) over the years didn't result in much improvement. If you want to get faster pay attention to aerodyanmics. And, while this is a video put on by a wheel manufacturer, the absolute biggest source of drag is the rider himself.

Did you watch part III? The talk by Jim Meyer about using the power meter as a tool to improve aerodynamics?

 

[FrankDay]

Did you watch part III? The talk by Jim Meyer about using the power meter as a tool to improve aerodynamics?

Did he discuss how the science shows that using the PM results in better outcome than not using one when trying to optimize racing position and speed?

Come on, this is a thread about how one might do an even better job at optimizing aerodynamics, not how a PM is useful in this task. Just because you have used your PM to optimize your position on 175 cranks is not evidence your aerodynamics cannot be improved further using a different crank length.

Just because there is zero science to prove that using a PM is beneficial to the racer does not mean it is not or cannot be useful. There are lots of things out there that don't have good scientific support that might actually have some usefulness, don't you think?

 

[FrankDay]

Boardman was one of the most aerodynamic riders out there. His power for the 1996 Hour record was well below the power Merckx put out for 60min in a lab test in Belgium after he broke the Hour record in Mexico.

Too much trouble?

Well if we are experimenting with crank length then we have to take the following into account...

* How long do we test? Some would claim it takes 3-9 months to see a change in improvement.

Really? Who? Not me. I think our experience shows the aerodynamic benefits are seen almost immediately and it takes most only a week or so to adapt to a new length as long as it isn't too extreme. Drew Peterson has moved from about 165 to 110 in about 1 month to the point he is ready to do the Everest Challenge on them.

* We should test one item at a time? Some would claim we need to "exclusively" use one position or one piece of equipment. .

Life is full of difficult choices. Why you are paid the big bucks to make that decision

* How do we control for confounding variables? Training, diet, recovery, weather, motivation etc could have affected the result. How do we "control" for those factors?

Life is full of difficult choices. Why you are paid the big bucks to make that decision

* How do we compare this method of lowering frontal area with other methods? There are other ways to change body position on the bike and the reason I test riders in the wind tunnel with a power meter is because the best position may not be optimal for power delivery.

Life is full of difficult choices. Why you are paid the big bucks to make that decision

* What about opportunity cost? While performing this 3-9month experiment manipulating one variable exclusively we are missing the opportunity to conduct other experiments. 100% improvement in a short term test to exhaustion from 2 weeks of SIT training. That's 12 minutes of training stimulus. Now we know that people don't do tests to exhaustion in competition but if we are experimentering (sic) for performance gains a proven 100% is better than a claimed 30%.

Life is tough. Some may choose to take this path while others may take another. The choice of what to do is up to you. I took the path less traveled and it has made all the difference.

 

[CoachFergie]

Did he discuss how the science shows that using the PM results in better outcome than not using one when trying to optimize racing position and speed?

Staggers me that people confuse measuring performance with improving performance.

Come on, this is a thread about how one might do an even better job at optimizing aerodynamics, not how a PM is useful in this task. Just because you have used your PM to optimize your position on 175 cranks is not evidence your aerodynamics cannot be improved further using a different crank length.

Alex has very astutely suggested that a power meter is an excellent way to measure optimisation of aerodynamics and as a side benefit ensuring that any improvements are not outweighed by a loss of power.

 

[CoachFergie]

Really? Who? Not me. I think our experience shows the aerodynamic benefits are seen almost immediately and it takes most only a week or so to adapt to a new length as long as it isn't too extreme. Drew Peterson has moved from about 165 to 110 in about 1 month to the point he is ready to do the Everest Challenge on them.

Anecdotes are a pretty poor form of evidence. If you had wind tunnel data or a Chung test to support an optimisation in aerodynamics and no cost to power delivery you would be halfway there. I assume Mr Peterson is still training so perhaps any improvements are related to that, diet, recovery and motivation.

Life is full of difficult choices. Why you are paid the big bucks to make that decision

Hmmmmmm a hypothetical gain or claim against a proven gain. Tough choice.

Big bucks. Must be why I left a well paying job to go back to school to get my Masters. If I was in it for the money I would be getting people in the gym for personal training sessions, getting back handers from supplement and equipment manufacturers and taking payments to endorse various products or carry out research on them.

 

[Shady87]

The opportunity and equipment cost of testing an equipment change with as much variability as crank length is huge, and is likely a factor as to why such testing has never been conducted to a degree which would come to a significant conclusion.

The experiment would require testing a range of crank lengths, setting up each athlete on a bike to allow adaptation to the length, setting up each in a position which would optimise aerodynamics and power output. Testing on maximal power, power over set time periods (5s, 30s, 5min etc), metabolic efficiency over a range of cadences at each crank length.

Such testing would probably take more than a year, with almost exclusive use of a wind tunnel, and lab facilities.

The testing would require a large group of athletes, about 30, to get the confidence interval sufficiently precise. The athletes would need to be of a standard that their physical condition would not change too much over the testing period.

Finding any athlete willing to compromise their own training to be part of such a testing protocol, which may well provide no real benefit to the athlete, is a very difficult task, let along a large group of such athletes.

 

[FrankDay]

The opportunity and equipment cost of testing an equipment change with as much variability as crank length is huge, and is likely a factor as to why such testing has never been conducted to a degree which would come to a significant conclusion.

The experiment would require testing a range of crank lengths, setting up each athlete on a bike to allow adaptation to the length, setting up each in a position which would optimise aerodynamics and power output. Testing on maximal power, power over set time periods (5s, 30s, 5min etc), metabolic efficiency over a range of cadences at each crank length.

Such testing would probably take more than a year, with almost exclusive use of a wind tunnel, and lab facilities.

The testing would require a large group of athletes, about 30, to get the confidence interval sufficiently precise. The athletes would need to be of a standard that their physical condition would not change too much over the testing period.

Finding any athlete willing to compromise their own training to be part of such a testing protocol, which may well provide no real benefit to the athlete, is a very difficult task, let along a large group of such athletes.

If you say so, I guess.

 

[CoachFergie]

The opportunity and equipment cost of testing an equipment change with as much variability as crank length is huge, and is likely a factor as to why such testing has never been conducted to a degree which would come to a significant conclusion.

What is your take on the Martin and McDaniel papers? I see these as the point where I go big investment in time (that could be spent pursuing more promising gains in performance) and money (that could be spent on getting to more events and testing the athletes in competition) and move along.

The experiment would require testing a range of crank lengths, setting up each athlete on a bike to allow adaptation to the length, setting up each in a position which would optimise aerodynamics and power output. Testing on maximal power, power over set time periods (5s, 30s, 5min etc), metabolic efficiency over a range of cadences at each crank length.

Once you go beyond maximal power would you not find training adaptations confounding any changes in power or metabolic efficiency?

Such testing would probably take more than a year, with almost exclusive use of a wind tunnel, and lab facilities.

If you wanted meaningful measures.

The testing would require a large group of athletes, about 30, to get the confidence interval sufficiently precise. The athletes would need to be of a standard that their physical condition would not change too much over the testing period.

Finding any athlete willing to compromise their own training to be part of such a testing protocol, which may well provide no real benefit to the athlete, is a very difficult task, let along a large group of such athletes.

Yes the catch-22 of the ideal subject being the person least likely to want to **** around with things if whatever they are currently doing is working for them.

Most of my "experiments" as a coach revolve around getting the riders to race more to gain experience and to "test" them in competition and to try and recreate the competition environment in training.

 

[FrankDay]

Did you watch part III? The talk by Jim Meyer about using the power meter as a tool to improve aerodynamics?

Am watching it now. And you folks complain about my unscientific claims. LOL. Here is an example of one of the more egregious overstatements regarding a PM.

"You can't improve if you don't have a way to measure your current status."

 

[FrankDay]

Am watching it now. And you folks complain about my unscientific claims. LOL. Here is an example of one of the more egregious overstatements regarding a PM.

"You can't improve if you don't have a way to measure your current status."

In this entire presentation there was not a single reference to a scientific paper. Now, the chung paper is a scholarly paper and a true advance but it is not a scientific study.

So, lots of interesting stuff that appeals to the geek in us but not a scintilla of scientific evidence that any of this stuff actually makes a racing outcome difference.

 

[CoachFergie]

Am watching it now. And you folks complain about my unscientific claims. LOL. Here is an example of one of the more egregious overstatements regarding a PM.

"You can't improve if you don't have a way to measure your current status."

Not going to lie, that is a rather silly claim to make.