The "SS" series is the most popular style clutch used by the O.E.M. since its introduction in 1970. The clutch comes in many different styles and configurations to meet any O.E.M. requirements. The standard clutch has a broached 3/16" keyway with two set screw holes located 90 degrees apart. The two set screw holes are tapped 1/4"-28. The recommended key length is 1/2". A special IK (internal key) clutch can be ordered for 3/4" crankshafts that has a key built into the hub. There are no set screw holes in the IK clutch and it has to be held on with a bolt and washer.

The "SS" clutch is the most popular choice among fun kart manufacturers. The secret to its success is its ability to take heat without ruining the garter spring. The spring is made from 302 stainless steel and it can take more than twice the heat of music wire used in competitors "look alike" clutches.