replacement speedometer gear schwinn air dyne qty 2
$16.00
This is a 3D printed speedometer gear that should revive your classic air dyne speedometer.
The shaft is .25 inch diameter, the square drive is for a speedometer cable that is .100 inch across the flats.
Troubleshooting your bike. Disconnect the speedometer cable at the fan hub. Move pedals slowly, if the square drive isn't rotating, the teeth of the gear are probably sheared off.
Quick and easy way to replace is to bend the speedometer cable tab up enough that the old gear shaft can push out. Clean bore with cotton swab and alcohol. Lightly oil new gear shaft, insert and bend tab back. Move pedals verify shaft is turning properly. Reconnect speedometer cable and enjoy.