Angular momentum and Big wheels [ RE: Double Wheel Giraffes ]

>Anyway, a few thoughts on the angular momentum of unicycle wheels. Any effects
>are likely to be small as the wheel is light (1 kg or so), of modest radius
>(30cm), and is not spinning quickly (10km/hr). Gyroscopic effects are
>noticeable on bicycles at speed, ie countersteering, but are not essential for
>bicycle stability.

It is true that the effect of angular momentum on normal standard unicycles with
20 or 24 inch might be relatively small. But angular momentum on most any big
wheel is a force that could cause a rider to wipe out. The typical big wheel is
about 40 inches in diameter. I’d guess that the weight of the rim and solid
rubber tire might be as much as 10 lbs. total.

Try riding the big wheel at 10-15 mph (16-25 kph) down a straight road and then
attempt to lean over to turn onto a side road. The unicycle seems to resist
your attempt to lean into the turn. Even at as slow as 10 mph, the effect of
angular momentum can be quite striking on a big wheel, because of the heavy
tire and rim.

Stay on Top, with big wheels,

Ken Fuchs <kfuchs@winternet.com>

P.S. Maybe we can hold UNICON VIII (1996) in New Zealand!