Do realize pretty much any small pneumatic wheel is being for shooting Frisbees is being used way outside of its design parameters. So you need to make everything as good as you can. Make sure the supports for the wheel are beefy (highly technical term. If you can, use bearings on both sides of the wheel. do not depend on the motor bearing to support the wheel. Lunch with Andy (above) also points out the importance of balance at high RPMs.
We have been running our wheels with no air in the tubes just depending on the stiffeness of the side wall &
centrifugal force.