[saddle tramp]

I'm looking to replace my wornout crankset which has 175 length crankarms. I can not find a replacememt with this length. I can find one on ebay w/172.5 crankarms.

Will I notice the 2.5 difference? Will I have to raise my saddle up to compensate?

TX

 

[kkowalsk]

My previous bike had 175's and my current bike has 172.5's. I really can't tell the difference.

Maybe I could of noticed it if I had changed the cranks on one of the bikes instead of changing bikes as well.

 

[C-40]

???

I'm looking to replace my wornout crankset which has 175 length crankarms. I can not find a replacememt with this length. I can find one on ebay w/172.5 crankarms.

Will I notice the 2.5mm difference? Will I have to raise my saddle up to compensate?

TX

I assume you want the same model of crank, even if it's outdated? Otherwise, finding 175mm crankarms shouldn't be tough. If only the chainrings are worn out, then you could rebuild the crank with new rings.

You may notice that the shorter crank is a little easier to spin, but provides less leverage. The leverage difference doesn't amount to much (1.5%). You can raise your saddle if you think that the bottom of your stroke is more critical than the top, or do nothing to split the difference between the top and bottom of the stroke. There is no hard and fast rule.

 

[SystemShock]

I can definitely tell the diff between 172.5 and 175. I tried 175 for awhile, but with my 82cm inseam, it was just too big a circle, it felt 'wrong' and I wasn't smooth.

I went to 172.5 and my pedaling got a lot more fluid. It's a nice blend of power and smoothness for me. I like it better than 170. But I'm someone who pays a great deal of attention to feel.

I wouldn't necessarily change your saddle height if you change your crank length though. It never seemed to help, and I fiddled around a LOT with it. Plus (though this doesn't apply to your situation of going to shorter cranks) it can be a little dangerous if you're already at your safe max saddle height and you increase it still more.


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[saddle tramp]

We are actually talking 2.5 millimeters difference not 2.5cm? 2.5mm's is pretty small.

 

[SystemShock]

Yup, 2.5mm. For some reason, it does make a difference, at least to some. It's not really that unusual for small changes to be noticeable... for example, if I were to change my saddle height by 2.5mm, I'd feel the difference.

Plus, to be fair, another 2.5mm on your cranks adds about 16mm to your pedaling circle.