The importance of crank length to the cyclist.

[Boeing]

coachlurgie, are you listening?

 

[cromagnon]

Didn't a british timetrial champ ride with a 60 cadence and really stupidly short cranks and the most absurdly huge egg-shaped chainring in the history of cycling.?

It was 3 or 4 years ago, it wasn't hutch but some other dude. Help me out someone my google skills are failing me.

 

[CoachFergie]

Nothing. You collect, analyze, and report those numbers. There is no independent entity reporting coaching results and making you (or anyone else) accountable for your results. If your bosses decide to let you go I suspect it will be because your race results are unacceptable and you won't be able to save your job by showing them some numbers.

Good thing that coaching is more than what Frank Day suspects, claims or believes.

So you are telling us you have no scientific basis for doing what you are doing, it is all one big experiment?

Well unless all the independent variables are exactly the same leading into an event (the cyclist, the course, the weather, the competition, the rules (thanks UCI), the bicycle etc) one can not expect the same dependant variable. But a coach should follow a scientific process of testing, experimenting and measuring the results.

If we are lucky then there is research out there to guide our thinking. As Jim Martin has said often going shorter in cranks within reason does not cost you power and this can free you up if gains in aerodynamics are available. Nice to see you have concluded beyond the data that this means an increase in power. But this isn't your first indulgence in science fiction.

Well, all those numbers are evidence. Only question is how good is that evidence as regards helping the athlete reach their goal? Got any numbers to answer that question?

Why yes I have, I have power files from 2002 from some riders showing a progression towards goal events and a progression from year to year.

Really? Suppose her power numbers weren't very good, didn't explain her cycling dominance (yes, she dominates on the bike), how would this affect your assessment as to how good she really is?

Why would I compare her files with others? I only look at the progression of that rider against that rider.

Isn't it possible she has achieved at least the bicycle portion of her dominance by sacrificing power to achieve better aerodynamics?

You mean power/cda. I have often said there is a balance here. In my above list of variables there are numerous measures of relative power.

The only reasonable way to determine how good an athlete is, compared to other athletes, is to observe them in competition, not by looking at some power numbers.

Then you have no idea if they are really improving or not. I agree that testing in competition is the Gold standard. I note that Evan's used an SRM in the Tour de France. Now no one claims an SRM will improve performance but even Cadel in his greatest victory is measuring his performance. One would assume to test the process and to try and repeat it again.

But I don't use power meters because Cadel uses a power meter. I use them because they actually measure performance.

 

[Boeing]

ferg, a little help

start every thread with "I intend to prove that....."

then add" I will do so by showing that 1, 2, 3...."

and conclude with " because of 3, 2, and 1, the above is true..."

as a start

 

[Oldman]

ferg, a little help

start every thread with "I intend to prove that....."

then add" I will do so by showing that 1, 2, 3...."

and conclude with " because of 3, 2, and 1, the above is true..."

as a start

Don't engage in debates with people who "believe" and don't require proof. Data is not proof; it is often just statistics used to support a pre-supposed belief.

 

[FrankDay]

But I don't use power meters because Cadel uses a power meter. I use them because they actually measure performance.

I think you will find that power meters just measure power. Obviously, from what you wrote above, you feel differently but I think you will find that most feel that power is simply one of the elements that combine to determine the overall performance. Power meters do not measure performance.

 

[CoachFergie]

Power is an excellent measure of performance.

Using my winter series example I can show a rider what power they need to perform in any grade and how they need to distribute that power in the race.

Then they race and we analyse the data and see how good a job they did.

We use the results of the analysis to try and do better next time.

By comparing files from those who won with those who lost we saw that riders needed to look after themselves going out to the turn, use some effort to stay close to the front coming in to the finish and those with the lower relative 20min power were able to deliver more 30sec power at the end to win the race.

 

[FrankDay]

Power is an excellent measure of performance.

We will have to agree to disagree. IMHO, power is simply a measure of power, not performance.

 

[CoachFergie]

We will have to agree to disagree. IMHO, power is simply a measure of power, not performance.

Contradicting yourself again there Frank. You seem more than happy to accept power as relevant measurement. Otherwise why would you write...

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

.

Are you saying that improved power or not sacrificing power is just for the sake of power it or because it is a measure of <drum roll please> performance!

 

[FrankDay]

Contradicting yourself again there Frank. You seem more than happy to accept power as relevant measurement. Otherwise why would you write...

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

Are you saying that improved power or not sacrificing power is just for the sake of power it or because it is a measure of <drum roll please> performance!

I have no problem with saying power is an important part of the overall performance equation. I believe that wholeheartedly. However, "power" itself, alone, probably only equates to performance in weight lifting. In cycling many other elements come into play that define overall performance because I have yet to find a cycling race that rewards those participants who have the greatest power. If you or anyone out there reading this knows of one please let me know. High power is important to cycling success. I have seen zero data that suggests measuring that power is important to success.

 

[CoachFergie]

I have seen zero data that suggests measuring that power is important to success.

Still haven't figured out the difference between measuring performance and enhancing performance have you Frank?

We used a performance relevant metric to test our training theories.

Does doing 20min efforts at 95-105% of FTP increase power in relevant performance testing after a training block?

Should we eat a high fat or high carbohydrate diet?

Should we supplement with Beta Alanine?

Will shorter cranks allow us to perform better on the bike? Create a better W/cda than other positions?

Should we rest 0,1 or 2 days after an intense effort?

Do we produce the same power in the Tour de France if we have ridden the Giro before or not?

And a thousands of other little experiments that go into the performance equation that underpin the end result.

But when Chrissie Wellington wins an Ironman or sets a World Record I don't just assume that is was because she didn't have a coach, because she doesn't use a power meter, because she wore lucky red socks but more likely that she got more physiological, psychological and biomechanical things right than the others.

My race data analysis chart was twice the size and I have weeded a lot of stuff out and will prune things down more as I keep using it.

 

[FrankDay]

Still haven't figured out the difference between measuring performance and enhancing performance have you Frank?

We used a performance relevant metric to test our training theories.

Does doing 20min efforts at 95-105% of FTP increase power in relevant performance testing after a training block?

Should we eat a high fat or high carbohydrate diet?

Should we supplement with Beta Alanine?

Will shorter cranks allow us to perform better on the bike? Create a better W/cda than other positions?

Should we rest 0,1 or 2 days after an intense effort?

Do we produce the same power in the Tour de France if we have ridden the Giro before or not?

And a thousands of other little experiments that go into the performance equation that underpin the end result.

But when Chrissie Wellington wins an Ironman or sets a World Record I don't just assume that is was because she didn't have a coach, because she doesn't use a power meter, because she wore lucky red socks but more likely that she got more physiological, psychological and biomechanical things right than the others.

My race data analysis chart was twice the size and I have weeded a lot of stuff out and will prune things down more as I keep using it.

Your insights are so awesomly amazing I really should pay more attention.

 

[FrankDay]

Fergie, what I find most amazing about you (and a few others here) is your total inability to discuss anything theoretical. If something hasn't been proven scientifically you have no interest in it or what anyone might say about it. Not all of us are quite that rigid. Anyhow, 3 more quotes recently received from people willing to try shorter cranks to see what might happen. Enjoy.

#1 writes: "Oh man. rode the 145mm length cranks on the valdora. This was awesome. I felt like i was climbing faster heart rate lower more comfortable. more aero. flat back. … Overall was a dynamite ride and I am sold on the 145s. will go down slowly from here and see when i bottom out. I felt like i could still climb real well with this length. out of the saddle was good too." … "There came a point in the ride about half way thru coming down from santa ysabel i was pulling and pushing with equal force and it felt good - like a machine. normally on longer cranks it's just a lift push motion - now it was pull push."

#2 writes: "I had a great ride today on 130's. Rode one of my normal routes faster than last time I rode it although it was first day I felt good in a couple of weeks. I haven't adjusted the gearing yet. I'll keep you posted."

#3 (this fellow is doing a crank length study and being blown away by the preliminary results) writes about his friend Tim: "Tim, today, took first in a local sprint. The best part is that neither of us is "training" right now. We're just 'goofing off' in relative terms and showing large differences. oh, and he did it nursing a calf injury. he commented that he owes the performance to both PC's and 130mm cranks." (Tim raced on 130 mm PowerCranks)

Anyhow, to those here not afraid to try something different, I would suggest experimenting with shorter cranks and see what happens. If you need to wait for others to prove that something works before you will try it I would suggest you wait.

For those of you who demand "real" evidence before trying something different ignore the following. Here is another report. Enjoy. (I am not sure what length crank he is on here but I think it is 145mm)

Just thought I'd share some data showing where I'm at before starting training with the short powercranks.

I always check in with my mileage at the 1hour mark on my bread and butter training route. clock starts while the legs are cold on a mile long false flat into a 2mile descent (old redmond road) then it's all rollers and back up the hill.

The best ride I ever did on 172.5's I was at 21.06 miles at 1hr, and the hill in 8min 14sec. This was fresh off powercrank training. I can't vouch for the accuracy of the wattage calculator on bicycleclimbs.com, but nevertheless, it gives me a 260 watt average for that climb.

Today, only two months later, I did the same ride at 23.02 miles in an hour, and I rode the hill in 6min 59 sec. wattage calculator gives me a 327 watt average.

When I include the climb and cool down, my average speed drops to 21.9mph. that's still faster than my best 1 hour time on 172.5's, and they both were max efforts. It's not 100% clear how much wattage I've actually gained, but it's impossible to deny the improvement. Every time I go on this ride, I get faster. It's unreal.

 

[CoachFergie]

Truly amazing watching you and the Gimmickcrank faithful delude yourselves using speed and time from different days as a performance metric.

 

[Oldman]

For those of you who demand "real" evidence before trying something different ignore the following. Here is another report. Enjoy. (I am not sure what length crank he is on here but I think it is 145mm)

Let's see...the guy goes up the hill for two months and his time is faster? How much time is out of the saddle/seated? How tall is he?
So far none of this qualifies as data. I also ride Old Redmond Road all the time and I'm sure I've seen this guy...

 

[Tapeworm]

After two months of training a person shows positive adaptations to training??

Do physiologists know about this??

 

[Shady87]

I've done testing on this issue.
Using a range of people, all highly trained athletes, mainly rowers, who are recreational cyclists (deliberately not trained cyclists, so that they haven't adapted to a particular crank length).

On a range on crank lengths from 100 to 205, the peak efficiency (power in measured by respiratory analysis, power out by power meter) for a steady submax effort occurred when using either 145 or 160 cranks for all of the subjects.

Big drop off occurred using 130 or below, and 190 or above. The average height of the group was about 6'4" so fairly tall. The difference between the 145, 160 cranks and the 175 was about 3% on average, the very long and very short were about 6-7 % worse.

 

[CoachFergie]

Very cool, is this published or to be published?

Were the differences between the crank lengths significant and were there any trends in power?

 

[Oldman]

I've done testing on this issue.
Using a range of people, all highly trained athletes, mainly rowers, who are recreational cyclists (deliberately not trained cyclists, so that they haven't adapted to a particular crank length).

On a range on crank lengths from 100 to 205, the peak efficiency (power in measured by respiratory analysis, power out by power meter) for a steady submax effort occurred when using either 145 or 160 cranks for all of the subjects.
Big drop off occurred using 130 or below, and 190 or above. The average height of the group was about 6'4" so fairly tall. The difference between the 145, 160 cranks and the 175 was about 3% on average, the very long and very short were about 6-7 % worse.

This is interesting information and hints at my primary issue with the PC "data". "Steady" and "submax" are relevant to the lab-based analysis and provides a good baseline for a length generalization. What the Salesman would have us believe is that shorter cranks (his brand, specifically) provides a benefit for performance based efforts. That reality presents huge variables in terms of effort demand, recovery and response to differing environmental conditions.
While a steady state effort could be sustained with a shorter crank and consistent rpms my suspicions would be that the variables would begin to favor a longer crank than average to allow usage of different muscle groups and body positions.
Cadel Evans didn't win the Tour sitting down in his drops.

 

[Shady87]

Coach, the research was for a Sports Engineering Honors project, completed last year. I'm not really sure what the uni does in terms of publishing, just internally I think.

Steady and submax were used because they are useful for lab-based analysis, which is what this was, and because you can get people to agree to the testing. Try finding any elite athletes willing to do a maximal test for a uni project without paying them.

There is another group continuing with the project, probably testing over a wider range of efforts. Not really sure how shorter cranks will go up a hill, when a rider starts grinding the torque really comes into it, and you simply can't get as much torque out of a shorter crank. This will be tested at some stage.

My feeling is the best application for shorter cranks would be for track endurance events.

 

[CoachFergie]

What cadence did you use for testing.

Interesting re application to track enduros. They tend to be going longer. The sprinters are going shorter and with the use of 35cm handlebars look like they are riding clown bikes. BMX use longer but their event is won and lost in the first 3 pedal strokes.

Did you make a set of cranks to test each length?

 

[FrankDay]

I've done testing on this issue.
Using a range of people, all highly trained athletes, mainly rowers, who are recreational cyclists (deliberately not trained cyclists, so that they haven't adapted to a particular crank length).

On a range on crank lengths from 100 to 205, the peak efficiency (power in measured by respiratory analysis, power out by power meter) for a steady submax effort occurred when using either 145 or 160 cranks for all of the subjects.

Big drop off occurred using 130 or below, and 190 or above. The average height of the group was about 6'4" so fairly tall. The difference between the 145, 160 cranks and the 175 was about 3% on average, the very long and very short were about 6-7 % worse.

The only criticism of your comment I have is everyone who is a recreational cyclist has adapted to the crank length around 170 mm as that is the crank length found on the vast majority of recreational bicycles.

Anyhow, your data supports the findings of Martin even though your protocol was completely different (1 rev max vs steady state power/efficiency).

One more question, were your subjects attached to the pedals so they could unweight efficiently or were they on platform pedals?

 

[Shady87]

We had the guys riding at about 90-95 rpm, not strictly controlled. They sat at a set, weight adjusted power level, give or take a few watts through the test. The cadence target was chosen because studies (I forget which ones, written down somewhere) show that the 'energy quotient' (VO2 per meter) is minimised at around 90-100 rpm. It's basically the easiest cadence to ride at.

We were using a Wattbike, fancy stationary bike. It allowed enough adjustment that we could match the set up of peoples own bikes, then adjust the seat height and handlebars together with the crank length to maintain torso angle, because that would have added another variable we didn't want.

Had to modify the crank mounts so that the Q-factor was a bit tighter (something that everyone seems to do for elite testing/training, people get sore knees otherwise). Made up a set of cranks with multiple pedal holes, 15mm apart. Would have liked multiple sets, but the cost of 8-9 custom cranks was a bit out of our budget.

 

[CoachFergie]

Here is a power point presentation by Jim Martin who has done several studies on the subject.

http://www.plan2peak.com/files/32_article_JMartinCrankLengthPedalingTechnique.pdf

And Jim posts his thoughts on the studies which debunk any suggestion of shorter cranks "adding" power as Frank would like us to believe. He did agree that it could open the door to experiment with finding a more aerodynamic position and he himself went to 165mm cranks on his TT bike.

http://forum.slowtwitch.com/gforum.cgi?do=post_view_flat;post=2705017;page=2

I have had several riders in the Wind Tunnel at Canterbury University Engineering Dept and they had no issues with achieving a flat back position with 175mm cranks. Others it is an option we will look at. I used to do TTs on my track bike till UCI ruled no fixed gear bikes on road and it had 165s which felt really good compared to the 170s I use on my road bike.

The "formulas" say I should ride 172.5s but they always feel just that fraction off.

 

[Shady87]

Frank, they were attached to the pedals (using cleats).
And most of these guys are high level rowers, at least state level, most have been national reps here in Aus.
Comparing the training adaptation of muscles due to 1-2 bike rides per week, maybe 5 hours tops, vs 8-12 rowing sessions (on water and indoor). If anything, the results would have been skewed in favor of longer crank lengths.