Schwinn AirdyneAD3 & AD4 The bikes are the same except for the display console. The AD3 used an analog speedometer and AD4 has a new electronic display.
Schwinn AirDyne AD5 Pro/Comp Air-Dyne AD5 Pro/Comp.
Earlier models of the Evolution used the same bottom bracket & crank arms as the AirDyne 4. New versions use a square bottom brac. . .
Schwinn Airdyne Evolution Pro/Comp Airdyne Evolution Pro/Comp
Earlier models of the Evolution used the same bottom bracket & crank arms as the AirDyne 4. New versions use a square bottom . . .