Sunday, June 08, 2008

IN SPECT YOUR WHEELS

Chasing down mysterious noises for a burly rider, I discovered long but faint cracks in the rim of his elderly Mavic Cosmic wheel, radiating from each drive side spoke hole. The most spectacular was hidden under the label, so it just looked like peeling graphics. That one was about ready to blow.

This wheel had not gone out of true. The only sign was a noise that initially seemed to emanate from the freehub bearings.

Another rider, who is at least six and a half feet tall, mentioned that his Campy Nucleon front wheel has cracks at most or all of the spoke holes. He says he's been monitoring them. He also reported that another rider is monitoring the same problem with the same kind of wheel set.

If people were folding wheels right and left we would heard about it, so maybe this is just unnecessary alarm. There's usually some warning. But with more people riding wheels with very low spoke counts and high tension, each component carries more load. The failure of a single part will markedly increase the load on the remaining parts.

When I called Wheel Guru on Thursday to consult about spoke gauges and whatnot, she mentioned that she was at that moment building a 36-spoke rear wheel for a brawny rider who has killed one Cane Creek wheel a year.

"He brings them in with the big hand grenade holes in the rim where the spokes blew out," she said. "I've finally convinced him he needs something stronger."

The large rider, 200 pounds and up, ages equipment more rapidly than someone in the mid and lower weight classes. They are the canaries in the coal mine for smaller riders, because eventually those of us of lesser bulk will accumulate enough fatigue in an alloy part to experience the same effect.

1 comment:

SuperJon® said...

maybe I could get sponsored to test wheels.