Crank Failures

See other failures under 000.html.

From as of 2004/01:

With the text

The Campy Only Retro Bike's left side crankarm gave up the ghost on a nighttime ride on May 31, 2001. Your C-O webmaster ended up flying over the front of the bike, shattering a helmet and getting a bit of road rash. A word to the wise: old Campy parts can break! Our crankarm showed no signs of damage or fatigue whatsoever, right up until it failed, but it's a good idea to keep an eye on critical parts like these on your own bike. (For an example of what to look for, check out this photo of a stress crack on the right-side crankarm . . . this has of course been taken out of service! Click on the image to see the cracks in the thin "web" area of the crankarm spider . . .)

The above says there were ``no signs of damage ... until it failed'', but note that in many cases there are cracks showing before the part fails. You have to know what to look for and you have to look regularly so as to find the cracks between their onset and the final failure. The break above shows a darkened area that usually has a suface crack. Clean cranks and examine them under bright light. Jobst Brandt reports he has broken dozens of cranks, checks his cranks monthly, and has caught them when cracked but not broken through in all but two cases.

See also FAIL-010.html