At 9/8/2006 03:45 AM -0400, Bianca Pratorius wrote:
>I have been working on bikes for a few decades now. Starting with
>the British 3 speeds that everyone had in the early 60's. I took
>apart many of my friends bikes and my own and my brother's. I never
>saw, or think I never saw a bent wheel axle nor a bent crank axle.
The Sturmey hubs have their bearings right next to the dropouts, much like modern cassette hubs.
As freewheels added speeds, the distance, and therefore bending leverage, between the right side bearing and the dropout became greater, while axle diameters stayed at 10mm. Cheap axles bend. Depending on the loads, good ones may flex past their fatigue limit and eventually break. Lots of stress risers in the roots of the threads.
IMHO any bent, as opposed to broken, BB spindle will be a case of inadequate heat treatment. Almost 30 years ago I took "Blind Al" Fryk, AKA "The Stoker From Hell" for a ride on my Paramount tandem. When we got back there was a 15 degree twist in the rear Phil Wood BB spindle. I'm still using the one Phil sent as a replacement.
Mark "We were out of phase, so I can't even take partial credit for the twist." Stonich;
Minneapolis Minnesota
http://mnhpva.org
http://bikesmithdesign.com