Interesting. How tall are you? What crank lengths do you have? I am 6'5" and was using 200mm cranks for years. I felt without question I climbed better with the longer cranks.

But I kept getting inputs from Frank Day to try shorter cranks, as well as read a few articles from some pro's who tried. The logic was this would help ones running off the bike.
I had changed my trainer to 175's, but still had 200's on my race bike. Was told not having the same was dumb, especially with this much of a difference.

So put 175's on my race bike also, and have had the fastest runs splits in Olympic races I have ever had, and my stand alone run races have been faster.

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Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

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Lions don't lose sleep worrying about the sheep

Meh... 175's on my road and cross bikes, 165 on my tri bike. I noticed the length difference in for maybe a few weeks when out on the road. Now it feels normal and I will still happily grind up a hill at 70-85RPM if the mood suits me. Pushing the pedals about 5% harder, shouldn't be that noticeable... and guess what, it isn't. You impact primarily by power generation, not pedal force. I'ts only when you stand up to climb that you realyl feel the short cranks.... but again, I only stand to stretch out and give my butt a rest every hour or so. I'ts less aero, harder to control your power and fatigues your legs more for running.

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How different are the lengths? And, is one a road bike and one a tri bike? If 5mm or less, I'd opine that it doesn't really matter. My road bike is 170 and my tri bike is 165. I hardly notice any difference since I'm used to riding both bikes. If the difference was 165-175, it might matter more, but as long as I don't close up my hip angle too much on the tri bike, I'm golden.

Ummm...what else did you change to allow for the ability to use the 200s? (Something that was suggested to you many times, IIRC ;-)

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http://bikeblather.blogspot.com/

Crank length? Whatever... http://bikeblather.blogspot.com/...erwithin-reason.html

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http://bikeblather.blogspot.com/

If you are geared for equivalent overall gain, then the pedal force and tangential pedal speed will be the same when climbing at the limit. Your muscles have a preferred shortening speed and can only produce so much force for a given duration. If the gain is correct, then power will be unaffected.

http://bikeblather.blogspot.com/...erwithin-reason.html

It's just that the cadence will be raised with shorter cranks since the smaller circumference circle it "draws out" means faster rotations for a given pedal speed. Cadence, as much as people like to focus on it, is REALLY a dependent variable, not an independent one.

Or, to quote Jim Martin: "Crank length and pedaling rate influence metabolic cost and efficiency only by influencing pedal speed."

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http://bikeblather.blogspot.com/

You know I did it totally wrong, but since I am back to 175's which is where my bike was fitted, things seem to be okay.

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Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

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Lions don't lose sleep worrying about the sheep

What was interesting is even though I was doing my trainer for 95% of my biking at 175's, when I raced or road a few long bikes outside on the 200's, I really did not feel the difference.

But where I did notice difference. It is so much easier to stay in the aerobars with the 175's. I seem to be able to push and hold a much higher RPM's during races.

And as I said, it sure has not seemed to have hurt my running off the bike.

So I would agree that really does it make that much difference?

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Dave Campbell | Facebook | @DaveECampbell | h2ofun@h2ofun.net

Boom Nutrition code 19F4Y3 $5 off 24 pack box | Bionic Runner | PowerCranks | Velotron | Spruzzamist

Lions don't lose sleep worrying about the sheep

My road bike has 170mm and tri bike has 165mm cranks.

I'm a tall guy (6"3), and ride 175mm on the road bike, 170mm on the tri bike. While I notice the difference, it's not critical either way. I feel like I climb and sprint better on the longer cranks, and hold steady-state efforts (with a more comfortable position) on the shorter ones. Each attribute fits the bike it's on.


Instead of standardizing crank-lengths, I standardized the cranks: Rotor 3Ds on both bikes, with a Power2Max spider. Now I can swap the power-meter back and forth without too much hassle. In the off-season group rides and road-racing season I can collect power data and track progress, and during tri season I can pace off key sessions.

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ZONE3 - We Last Longer

Have 160's on my tri bike, 165's on one road bike and 170's on another... with 172.5's on my Zipp 2001.

I can't tell a difference, other than fit purposes.

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Thank you all for the responses. Sounds like unless it is a big size difference, there is not a significant difference. I went from year's of riding 175 standard to a 170 compact in the winter. My climbing has certainly improved, mostly through the lower gearing and being able to spin a bit more and/or control my power more effectively on the short and steep power climbs in my area. It seems easier to spin the shorter cranks on those climbs. I still use a 175 on the trainer and any other bike I ride when I am too lazy to move the PM between bikes. I am now looking for a PM with standard chainrings and can get a 175 at a closeout price, which prompted this question.