Originally Posted by
Deontologist
http://www.bikeforums.net/road-cycli...-injuries.html
http://www.bikeforums.net/road-cycli...kes-again.html
http://www.pardo.net/bike/pic/fail-001/FAIL-202.html
I can't trust the bottom bracket. I've already suffered a crash (fortunately not from component failure) but I have had a component fail before That time I was not wearing a helmet and had things turned out differently I could easily have ended up under the wheels of a bus. I'd rather dance on the side of caution this time.
Also even if the cheap BB doesn't fail it will almost inevitably end up useless within a few months of use. I've had a similar cheap square taper BB on an old bike and the BB developed tons of play within two months of riding. You could easily swing the crank arms side to side. The bearings were shot. I had the bearings replaced and the entire thing tightened up but it was still a bit loose. Might as well bite the bullet now and switch to a reliable, durable bottom bracket.
It looks like these broken ones are all the hollow spindle ISIS type, which are a different animal entirely than the square taper type. As mentioned above, the square taper is unlikely to break, but a Shimano replacement is likely a $15 part, so replace if it makes you feel better. The bike shop will charge labor, of course. If you want to do it yourself, you'll need a crank extractor, the proper splined BB tool, and a torque wrench to install the new one to the proper torque.