Triumph BSA 250 500 650 Piston Wristpin Circlip(s) PN# 70-6869 W

The integrity of the wristpin, or gudgeon pin circlip, is critical to the assembly of the piston to the small-end of the connecting rod. Whenever the wristpins have been removed from the pistons and are to be put back into service, it is recommended that the circlips be replaced. Suitable for fitment to BSA A7, A10, B25 and Triumph 250 single-cylinder and 500/650 twin-cylinder models. 

These reproduction wristpin circlips feature a pair of tangs that allow for easier installation and removal. With a wire thickness of .047″ and an outside circle diameter of .788″, these circlips are suitable for fitment to a variety of pistons manufactured for the pre-unit BSA twins, as well as pre-unit and unit Triumph 500 and 650 twins.

The wristpin circlips are used as retainers for the piston pins and once fitted to the grooves in the pistons, limit the lateral migration of the wristpin within the piston.

The circlips are carefully pressed into the grooves around the wristpin recess on each side of the piston, working around the circle using a pick or small screwdriver. It is advisable to fit the inward facing circlip on each piston on the bench before pressing in the wristpin, minimizing the risk of dropping the circlip into the engine cavity. It is also suggested to stuff rags under the pistons to catch an errant circlip when installing the circlips.