Crank failure, seatpost failure

See other failures under 000.html.

Crank broke on first downstroke after standing up crossing a bike bridge. Rider's foot hit pavement but kept control while "sitting" on the top tube and holding the handlebars. Minor injury from saddle nose.

Rider continued riding one-legged. Soon, the rider leaned back on seat to clip remaining foot in, whereupon a bolt on the seatpost broke, releasing the saddle and dumping the rider.

Component notes:

Failure notes:


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Arm/spider failures occur because the load is transferred along a thin tapering knife-like edge that concentrates the greatest force along the edge. An alternative is to use a flattened transition, as in the following non-failed Sugino crank.

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See also FAIL-039.html

(FAIL-038.html for more broken seatposts)