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[cadence90]

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[markie]

I would stay the same, but if some other cranks came along in a different size I wold use them, too.

I have bikes with 170s, 172.5s and 175s and I really cannot tell the 5mm difference.

[bnewt07]

Only proviso I would have is regarding BB height. if you are riding on rockier stuff (and it sounds like not) then consider the BB height and pedal clearance. I ride slightly shorter cranks on my MTB for that reason as it has a rather low BB.

Bruce

[Lincoln]

For your stated use I'd say same (and agree with Markie, if you find a deal on something just a little shorter then go for it).

[Ray]

For your intended use, I'd also stay with the same length. I ride 170 on my fixie and 172.5 on my road bikes. When I was mountain biking, I used to ride 175s on that, but I never liked cranks that long on my road bike. I couldn't spin them as smoothly but like'd the extra uuumph they gave me during low speed maneuvers. But for just riding easy trails and fire-roads and stuff, I wouldn't change what I otherwise liked.

-Ray

[flickwet]

I would.

[Satellite]

I had the same delima; but reverse. My mountain cranks are 175 and my road cranks were 172.5. When I switched back and forth I couldn't seem to get my spin right. When I built up my new VaMoots I opted for the 175 to balance out the cranks across all displines. I ended up hating the 175's on my road bike. My spin was more mashy (it's a word), I switched them back to 172.5's and I was back in spin heaven. I know it shouldn't make much of a difference but it did for me.

I say longer on the mountain more leverage shorter on the road higher cadence. These are my results others may vary ( :banana: nice disclaimer).

Satellite

[Bernie]

pretty much the standard length for mountain cranks is 175. You can get other lengths, but nearly every new mountain bike regardless of the frame size comes standard with 175mm cranks. It has been explained to me that the reason is for leverage, but I doubt if it makes much difference. I've ridden bikes with 170, 172.5 and 175 and couldn't really tell the difference, but that's just me. For availablity and uniformity I would stick with 175mm for off road stuff.

[WadePatton]

I like longer off-road, but then I ride SS. My roadies have 170's and 175's. My ATB wears 180's. I'm probably going to raise my BB and make room for 190's on the next one. I get too many pedal/crank strikes at 180 to run the same BB height for 190's, but want to try the long ones...if I don't like 190's, then I'll simply have more clearance with the 180's.

And I really don't notice a difference when I change road bikes-as to crank length, the drivetrain differences are much more significant atmo. (Fixed, SS, geared)