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Master of Disaster
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Discussion Starter · #1 ·
I just upgraded a TruVativ Five-D square-taper 170mm crank to a Shimano Deore M590 HollowTech II 175mm crank. I'm 6'2" and so figured that 175mm would be a no-brainer. I've only got one ride on it though and thought it felt weird. Not sure if I like having the extra stroke or not.

Has anybody here moved from a 170mm crank arm to 175mm arms and regretted it ?

I'm running the new crank 1 x 9 via a Paul Components Chain Keeper (which I've had zero problems with over many months):

 

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Changed to 170s and found great, would go back to 175

Hi, I'm 184cm with 89cm inside leg. Changed to 170 for comfort and better feel excelerating. Have found it great now I have adapted. If you liked the 170 I would stick with it. There is some good research to show that a 175 does not give your more power etc. I think it is a matter of personal preference and riding style.
In the trasnsition I went back to 175 and confirmed that the shift was the right thing to do. :)
 

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If you're a spinner with smooth cadence you may notice the difference since you're so used to turning a smaller circle. That feeling goes away pretty quickly as you adjust to the longer length.

Just give it time.
 

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Master of Disaster
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Discussion Starter · #5 ·
FBinNY said:
That feeling goes away pretty quickly as you adjust to the longer length. Just give it time.
I rode the local trails today with the new crank and promptly forgot all about it feeling different.

On the other hand, I had way more pedal strikes today than I normally get on that course so the jury is still out on whether or not 175mm crank arms was the right thing for me to buy.

BTW; I'm just under 6'2", weigh 225 lbs and I'm riding a 29er hardtail. If I was on a full-squish bike, I think I'd be in serious trouble with these longer crank arms.
 

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I'm 5'10" and have been riding on 175mm cranks since I started riding close to 20 years ago. I'm on 172.5mm on the road. There was some theory or other back in the day that a mtn. crank arm should be longer than a road crank arm

NOW you tell me I probably should have considered 170mm :confused:

That's a couple of zillion pedal strikes :madman:

Will have to use the google to research this. Meanwhile, anybody have a favorite link or a prior thread which covers crank length?
 

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I realy think its just a matter of personal preferance. and Ive read alot of people state that the pedal strikes are why they dont like 175's. Im only 5'8" and I like the 175.

another thing to consider is the 175 will put more stress on your knees. due to the leg thats on TOP of the pedal stroke, your knee is bent alot more while seated/pedaling.

how much were those cranks? thinking I might start looking for another set of cranks for my new single speed.
 

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Master of Disaster
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Discussion Starter · #8 ·

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Crank length research

Hi All

Here is a link to the Martin research.
http://www.plan2peak.com/files/32_article_JMartinCrankLengthPedalingTechnique.pdf

Basically people adapt and there is no impact on power for a given length across a wide range (maybe .5% for the tallest and shortest riders). For me 170 is comfortable and way less pedal strike (surprising given it is only 5mm). Also keep in mind th arguement is related to foot speed and distance travelled per revolution not just the matter of the 5mm length difference etc.

I also think the comfort preference comes down to pedalling style and how high ones thigh comes up to the chest etc. ;)
 

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Sheldon Brown wrote a good bit regarding crank length, http://sheldonbrown.com/cranks.html.

Also Matt Chester wrote about it and I'm pretty sure he settled on shorter cranks despite his 6'2".

I'm 6'3" and am eager to try some 165s as I'd rather spin than mash.

If the cranks go round and round and don't fuss, it's all good in the hood.
 
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