[TR] Shaking TR3

[Randall]

> Allen at Hendrix WW will tell that even new tires can arrive out of
> round.

Indeed, they can even appear round on the balancing machine, but still cause
vibration when loaded, if there is a variation in stiffness.

But it rarely happens IMO; and like Bill I have been through several sets of
quality, modern tires without it making much difference.

My "aha moment" was when I was working on the front brakes, and discovered
that the hub would turn under its own weight, with no wheel mounted at all.
When I tried it at the bench (using a spare upright clamped in the vise),
spinning at only moderate speed (powered by a wire wheel on my angle
grinder) would shake the entire bench violently.

-- Randall