Originally Posted by Turbonium
perpendicular to the axis of rotation. basicaly pretending your a bicycle fork with your arms and moving the wheel upward in the direction of your head.
OK, I just tried this and cannot duplicate it. Also tried it w/ a gyroscope w/ the same result.
As far as I know, such a motion could never in itself apply any tangential torque to the wheel (or rather any *net torque* which would affect the wheel's spin-- the mass of the rim does provide a torque becasue of its inertia but, this will always be balanced equally by the opposite side of the wheel).
Is the wheel imbalanced or are the bearings loose/worn?