Glad you liked that, Brian.
The gyroscopic effect of the wheels on a motorcycle has long been
recognized. It is generally beneficial because the greater the speed of
the wheels/gyroscopes, the greater is their stabilizing effect since a
gyro wants to remain in its plane, and more so the faster it spins.
This gyroscopic effect can become detrimental to the quick handling of a
road-racing motorcycle at high speed because it slows the reaction of
the bike when the rider wants to bank and turn. Hence the practice with
such bikes, for about 70 years now, of using aluminum rims (when they
were spoked) and lightweight racing tires, and the lightest possible
brake parts (magnesium alloy hubs/drums/backing plates), and even light
"butted" (two diameter) spokes. I don't know that the ground contact
point has any effect in this matter.
With a speed trials bike the wheels would be a valuable stability
factor, straight-up.
I'm sure you're right that the crankshaft of a single or twin has a
gyroscopic effect inside the crankcase, adding stability to the machine.
I don't know about any gyroscopes on four-wheel streamliners, maybe
someone else can comment. Don't know if any use cross-mounted engines,
except where motorcycle engines are used in the small four- wheel
streamliner classes. Generally a streamliner is built with the smallest
possible front aspect.
Brian, being in New Zealand, are you familiar with the legend of when
Burns and Wright took the World Motorcycle Speed Record at 185 on a long
straight closed public road there in 1955? Vincent Black Lightning, of
course, a standard chassis with B & W's homemade fish-shaped streamlined
shell over it. Burns wrote a story about it, which exists in
manuscript, but was never published. Anyhow, the machine was geared to
6000 rpm at 185, so those Vincent flywheels were helping stability with
their gyro effect. "A lovely great mill" as Burns described the engine.
This record was set with "80-10-10" fuel by the way, 80% methanol, 10%
petrol (gas) and 10% benzole. No nitro down there at that time! I'm
sure there's plenty now. Cheers Bill
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