Had a crank arm snap clean off on a test ride yesterday

I was test riding a customer's old Schwinn after a bottom bracket overhaul and the right crank arm snapped right at the square taper about two blocks from the shop. Luckily I was going slow and didn't eat pavement, but I had to walk the bike back carrying the pedal in my hand. Anyone else run into random crank failures on older bikes, or was this just a fluke from metal fatigue?

3 comments

3 Comments

lily_cooper5d ago

Had a similar thing happen on an old Raleigh years ago... was just cruising along and the pedal sort of dropped. Lucky it didn't happen on a downhill.

fiona_hunt715d ago

Read somewhere that old steel cranks can get micro-fractures over time that you can't see until they let go. @lily_cooper's story about the Raleigh sounds pretty similar to yours, probably the same deal with metal fatigue on older bikes. Always a weird feeling when a part just gives up like that with no warning.

emma_garcia5d ago

Used to think cranks just didn't break like that. This thread definitely changed my mind though.