Installing the Schwinn Airdyne Wedge Pin
The following instructions for installing and removing wedge pins are applicable to Airdyne bike models AD3, AD4 and some Pro/Comp models. Each wedge pin has a flat edge that mates with a corresponding part. All parts that require a wedge pin will have a flat edge in one location. This allows the wedge pin to slide into position. To assemble the eccentric arm and cartridge, slide the eccentric onto the post of the cartridge, install the wedge pin and put the washer and nut on the back side.
Removing the Wedge Pin
To remove the wedge pin, use a wrench to loosen the nut at the top until there is a bit of play behind it. Use a rubber mallet to tap the top until the wedge pin begins to move down through the opening. Once the wedge pin slides easily, take the nut completely off the wedge pin and push the wedge pin out of the assembly. If the wedge pin has been installed on a machine for an extended length of time, it may be somewhat difficult to remove.
Installing Wedge Pins in the Proper Direction
When installing wedge pins during the crank arm assembly on Airdyne bikes it is important to be aware of the direction in which the wedge pins are installed. The crank arms on each side of the assembly should be at exactly a 180 degree angle from one another. It’s essential that the wedge pins on each side of the assembly are installed in opposite directions to ensure the crank arms are positioned correctly. If the wedge pin on the eccentric side has the nut up and the stud down, the wedge pin on the opposite side should be reversed.
Tightening the Assembly
Inside the nut, there is a nylon insert. The nut must be tightened sufficiently for the threads to grasp the nylon insert for it to hold properly. Proper tightening is accomplished by pushing the wedge pin in and starting the nut manually. Use a wrench to ensure it is thoroughly tightened. There should be no play in it at all. As a precaution, check the part after it has been installed for a while to verify that the nuts remain tight. If they are not seated properly, once the machine is in operation, they will begin to move. Even though the wedge pin may be seated correctly, if the nut isn’t tightened properly, there will be play between the moving parts that will cause the system to wear out prematurely.