Originally Posted by
Gramercy
I've read on here about bottom bracket issues - I don't really understand it. Do they wear over time from all of the torque applied to the pedals and, subsequently, the frame? Is there anything to look out for?
The issue with my frame is a bit different. The builder didn't face etc the frame after building. Ends up that BB30 facing tools are pretty hard to find. I bought a set for myself. However, when I first built up the bike, I used a file (I know I know) to enlargen the tight spots. Really imprecise. The bearings went bad basically the instant I put them in - on a down hill, going about 40 mph, soft-pedaling in a 39x25, I could get the SRM to read 15 watts by pedaling really fast while still hearing the freehub coast.
Facing has made it better but my hack file job basically screwed up my BB shell. Now the bearings creak and such.
Any press fit BB bearing moves - the first Gary Fisher BBs were a nightmare. When Merlin used the press bearing BB we replaced bearings all the time. A Trek dealer told me that all the BB86s (press fit Shimano) get loose and it's basically a normal maintenance thing to replace the bearings. They go more frequently than rear tires, which should be about the quickest wearing thing on a bike.
This time I hope to do a better job, build up the gaps with something, etc. Maybe it'll last until the end of the summer.