I have a 29 inch inside leg (max). Should i get a 170 or 175 crank for xc racing?

Won't matter.

Oh I forgot.

Shortarse!

farley buy a kids bike and have done! seeing as all your bikes have 175mm cranks stick with that. Its 5mm on a crank length, not like its 5mm on your cock 🙂

thanks, i know i'm a short arse 😀

why won't it matter? advantage of one over the other?

same difference rob 😉

With a 29" inside leg length, I'd recommend going for a 170mm crank. Shorter cranks will help you spin more easily. Though it doesn't make a massive difference.

Personally, even with 33" inside leg length, I prefer to run shorter cranks. It's more of an individual preference than a rule as to what you should run, but I think if you have got shorter legs, it's worth at least trying shorter cranks…