2 wheels vs 1 wheel in a linear shooter

[Andrew Zeller]

Originally Posted by Ether

With 2 wheels, the maximum frisbee speed is still half the wheel tangential velocity.

I also followed your math here:

It translates into approx 21 mph, assuming no slipping.

3600 rpm / 60 min/sec = 60 rev/sec

60 rev/sec * pi*4/12 ft/rev = 62.8 ft/sec

62.8 ft/sec / 2 = 31.4 ft/sec

31.4 ft/sec * 3600 sec/hour / 5280 ft/mile = 21.4 mph

I understand that the rotation of the frisbee as it contacts the wheel causes less than its full velocity to be transferred in an ideal situation, however why is it that the maximum exit velocity of the frisbee will theoretically be one half that of the tangential velocity of the wheel?