Had a crank arm fall off mid-ride on Tuesday, what a mess

I was climbing a steep hill in Portland around 5pm and my left crank arm just came loose and dropped off. I carry a multi-tool but the bolt had stripped out completely, meaning I had to coast down to a shop 3 miles away. The mechanic there told me the square taper interface was worn down from years of riding without checking torque. I replaced the whole bottom bracket and crank set for $45 and another hour of shop labor. Has anyone else had a crank arm fail like that on a older bike?

2 comments

2 Comments

the_olivia25d ago

Check the crank bolt not the crank arm torque, different thing entirely.

abby_robinson5825d ago

Why didn't the shop catch the wear when you brought it in for a tune-up last time? I had the same thing happen on my old Trek, and now I just check the bolt torque every few months with a small wrench. A little preventative maintenance goes a long way before you're stuck coasting downhill with one pedal.