On Fri, 11 Jul 2003 13:22:48 GMT, Jasper Janssen
wrote:

I wonder what would happen if, as a physics experiment, you laced a wheel
with a single steel cable, using appropriate sized pulleys at the hub and
the rim, and a single inline tension adjuster at one point. The pulleys
would have to have fairly heavy duty bearings to roll under 200 kg
tension, though, I don't think a bushing is gonna do that trick. On the
other hand, even at relatively severe deflections of the rim, the pulleys
would have very little actual movement to do in order to equalise the
spoke tension across the wheel.

Hmm. If 'spoke' tension is always equal on each of the spokes, then
there's no force holding up the hub, and thus the hub would fall down to
the ground instead of being held up.

Oh well, there goes my experiment.

As someone pointed out in email, I missed an important thing: As the hub
does its sagging, the "spoke"/wire angles change and provide a net force
upwards. So the wheel should behave more or less[1] as the
rigid-rim/rubber spoke model: as you're riding along, the hub will be
positioned slightly (or maybe a lot) below the center of the rim.


Jasper

[1] In several ways less, of course.