Hello,

I have medial pain in the left knee, and a bike fitter recommends to change crank arms from 172.5mm to 165mm. The bike I have is a 2016 Giant Fastroad SLR 1. The specs sheet simply says crankset is an "FSA Omega, 34/50" and bottom bracket is "FSA, Press Fit." I googled for more info and found that the bottom bracket may possibly be BB86/PF86.

Since the bike is new and for cost, I want to change only the crank arms. I also want to search Craigslist used parts first. So, I would like to know if I need to stick with FSA Omega to avoid incompatibility, or any FSA crank arms would work? Also, if you know of any cheap online place, I would love to know, too.

BTW, I'm very new to bicycling (last June/July). So far, I have lubed bike chains, but nothing else. I have watched Youtube videos on removing and installing FSA cranckset, and the process simple enough that I'm sure I can do it. However, if you have any tips or suggestions, please, let me know.

Thanks in advance for your help