[ChrisRobin]

Hey, not exactly sure where to post this but I figure this would be the best forum.

I bought a 15" Kona freeride hardtail off a buddy for my gf. She only rides on the roads and I can't stand the walmart-level bike she has now which is why I bought this thing. Sooner or later I'll try to introduce her to a little bit more dirt.

So she's only 5' tall and the cranks on the bike are 170mm (the cranks on her old crap bike were 170mm as well). The current cranks are Truvativ Hussefelts which are dead heavy but I have a full older style XT octalink crankset collecting dust. I'd install those but they're 175mm. Am I going to cause problems installing those?? I don't want to cause knee pains or discomfort. Is there a formula somewhere for cranklength vs. rider height?

Thanks a lot!!

 

[sanjuro]

I don't think it will matter for a total novice, but here is more info for you:

http://www.zinncycles.com/cranks.aspx

I would probably get her 170mm crankarms in the future, but my reasoning is just tradition.

 

[ChrisRobin]

Thanks for the info... I'll keep 170mm cranks on there in the meantime until I can find el-cheapo octalink cranks.

I'll focus my attention on getting lighter wheels, maybe even 24" since she's so short.

 

[cyclemom]

I'm almost 5 ft.
The whole bike sounds too big for her. and too heavy to boot. I ride a Gary Fisher extra small Big Sur - that is a 13 inch frame from center to top of seat post, or around 11-12 inches center to center with stock 170 cranks. Every time I ride (borrow) a 15 inch frame - I feel totally spastic. My daughter is same size as me, rides the same frame, but with 165 mm XT cranks, she says it is a lot better as she can spin better instead of having to "throw her leg over the top" of the arc.

 

[ChrisRobin]

Yeah I think you're right... I could get 24" wheels but that's not 'really' addressing the problem.

 

[JRogers]

Yeah I think you're right... I could get 24" wheels but that's not 'really' addressing the problem.

Agreed. Of course, there's no way to tell without more info or seeing her on the bike, but at 5', a 15" is likely too big. You'd be better off buying a new frame than new wheels. All the wheels will do is decrease standover anyway- not make the frame smaller.

And I doubt most cyclists could tell the difference between 170s and 175s, let alone a novice on a bike that's too big anyway.