Would it be wrong to run different crank arms?

Discuss light weight issues concerning road bikes & parts.
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zakeen
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by zakeen

So would it? be wrong to have a different crank arm on the left to the right?

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Ivan
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by Ivan

zakeen wrote:So would it? be wrong to have a different crank arm on the left to the right?


To compensate for a length difference in your legs ? Not a bad idea IMO but I am not an expert in ergonomics to give you an answer.

by Weenie


stumpytrunks
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by stumpytrunks

Only problem I could see is your foot moving forward and back further on one side. Might need to twist your saddle slightly to accommodate. This might hurt your back. Ive got no real idea though but it sounds fairly logical.

Francois_Viviers
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by Francois_Viviers

This idea does not make sense, first off all the tuanbility is not completely right you would be stuck to increments off 2.5mm.

When both pedals are at 0 and 180 degrees the difference would not be as pronounce as at 90 and 270 degree. This would make for and unsmooth stroke. By doing this you are creating a compensation for leg lenght difference at the bottom bracket, whereas using shoe wedges would create a compensation at the axle on the cleat. Seeing that your foot stays in generally the same position and there is never a full rotation the adaption would mostly stay the same through the motion, unless you angle your foot a lot, some angulation is normal anyway.

A cleat wedge system is a far better/safer solution. But then again if you want to try 2 different cranks...... just let us know how that goes

jozuph
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by jozuph

jus wondering zakeen, why do you want to do that ?

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drjones96
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by drjones96

I've heard of doing this to compensate for leg lengths not being exactly the same. Another option would be to use spacers on the cleats on one foot. That is IF indeed your issue is that you have one leg longer than the other. If that isn't your issue I don't know why you would do this.

marko
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by marko

Spacers in the cleat area would be an easier and more effective way as you need your shorter leg longer at the bottom of the stroke as opposed to all the way around as a short crank would do.

PNuT
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by PNuT

were does it say in the origional post different lengths? maybe the poster wants to use shimano one side & campag the other :shock:

zakeen
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by zakeen

PNuT wrote:were does it say in the origional post different lengths? maybe the poster wants to use shimano one side & campag the other :shock:


Exactly!!!!!!!!!!!!

jozuph wrote:just wondering zakeen, why do you want to do that ?


Well Dr. Lothar Heinrich(t-mobile) and ww.srm-sports.de kindly gave me a pair of SRM cranks. It is the older versions, so it uses a DA bottom bracket. I also have an old pair of DA cranks that were hardly ever used, so I was thinking... could I use the left side of a DA and the right side of SRM?

its a 35 grams save for zero cost! but my concern is, on is much stiffer then the other, would that matter or not?

Geoff
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by Geoff

I have the same deal with SRM cranks on my bike. Rather than pull both sides of the cranks when I swap the SRM around between bikes, I leave the non-drive side crankarm on and just change the Powermeter. The Record and SRM "Q" factor is very close, so I have never noticed any difference. Additionally, the Record crankarm is lighter than the SRM, I am sure it is the same for the Dura-Ace.

beavisbnc1
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by beavisbnc1

I have seen this done with a campag arm on the left coupled with an srm on the drive side, and it worked perfectly for that person, so go for it. If i could afford an SRM thats what I would do

by Weenie


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