White Industries M/R30 Adjustable Crank Arm Ring (Silver)

Otherwise know as "bearing pre-load collars", the White Industries M/R30 adjustable crank rings are a part of the non-drive side crank arm and are used to adjust the bearing pre-load of the bottom bracket. Note: The collar must be threaded all the way onto the crank arm before installing the arm onto the spindle, otherwise damage may occur to the BB bearings or the collar.