BSA Crankshaft Roller Bearing Shim Cup (1) 71-3288 - 1966-72 - A50 / A65 Nicholson M Part number is 70-8003

M Part number is 70-8003

BSA A7 and A10 models from 1957-1963 and many other late model applications

OEM part number is 70-4148

M Part number is 60-2076

BSA & Norton models from 1960's through the 1970's with a Single Carb or Dual Carb that include both Monobloc or Concentric Series

BSA Crankshaft Roller Bearing Shim Cup (1) 71-3288 - 1966-72 - A50 / A65 Nicholson M Part number is 70-8003*Stock Is Limited!* New Top Quality BSA Unit Twins Crankshaft Roller Bearing Shim Cup Retainer. With the Modern Replacement Roller Bearings on the Market today, they are "Slightly" different from the Original Hoffmann Roller Bearings, which means you have to use this Shim Cup in Conjunction! Specifically, New RHP Roller Bearings (70 2879 or 68 0625) have a slightly Wider Inner Race then the Stock Hoffmann Bearings causing the Shim Cup not to fully fit