Originally Posted by
Unapomer
My suspicion is your LBS didn't screw the crankarm puller in all the way to pull the left arm off to access the bb and that's their bad and they should be responsible for replacement.
That's pretty likely. I've come across guys in shops who seem to think cranking the puller into those threads hard is a good idea, too - that's another way to trash those fine ally threads. The puller only needs to be finger-tight.
Originally Posted by
andboy
Or can I use any size e.g. 170 or 175mm?
Depends on your leg length and riding style. I'm 5'10" and pretty good at spinning, so when I tried some 175s after only ever using 170s, I really liked them. I had noticeably more power, and the extra length didn't incur much of a redline penalty cause of my height and spinning ability.
It wasn't a
huge difference though; I would have only just noticed a 2.5mm change.