Bifold Door Parts

Bifold hangar doors carry their entire weight on cable or lift strap, which makes the lifting system the part of the door that needs the most attention. We stock the drive, sealing, and electrical parts for bifold doors: steel cable, polyester lift strap, cable clamps and thimbles, turnbuckles, mast guide bearings, cam followers, extension springs, rotary limit switches, and EPDM weather seal.

Cable and lift strap on a bifold door

1/4 in. galvanized steel cable is the standard on most bifold doors, sold by the foot with matching clamps and thimbles. The thimble loops the cable back so the clamps can grip without the cable slipping under load. Polyester lift strap is the alternative: it does not corrode from the inside the way galvanized cable does, and on buildings where cable is already being replaced early, the strap generally lasts longer.

Bearings, cam followers, and springs

Mast guide bearings handle the heavy-load side of a bifold door and use a hardened steel outer ring with single row construction. Cam followers, also called track followers, are roller or needle bearings that ride the cam lobe profile on the door. Extension springs create tension at specific points in the assembly. All three are wear items, and we can custom fabricate cam followers in sizes we do not stock.

Rotary limit switches for bifold doors

A rotary limit switch reads shaft rotation, which lets it set adjustable limits across the door's entire range of travel. That is why it is the standard choice on bifold doors rather than a snap-action switch that trips at one fixed point. If your door is over-traveling or stopping short of the seal, check the limit switch before assuming the motor is at fault.

Bifold hangar door parts: common questions