The difference between the dimensions of the two shafts (.1mm or .004") is a lot! Which dimension is the correct one? I am guessing the smaller one.
I am always supecious of NOS parts as on a few occasions (not just BSA) you find out after having bought the part the reason it was sitting on the shelf unused for many years as it was made wrong.
I currently have a NOS Triumph pre-unit clutch basket I bought a few months ago still wrapped in paper that the bearing race was ground too big by about .012". So now I know why it was NOS after 50 years. Also have a NOS BSA M21 output gear where the splines were made wrong and the drive chain sprocket won't fit.
Stop, the difference between the dimensions of the two shafts (.1mm or .004") is a lot! Which dimension is the correct one? I am guessing the smaller one. Unless there is evidence of .004" wear on the old shaft. Something is wrong.
I am always supecious of NOS parts as on a few occasions (not just BSA) you find out after having bought the part the reason it was sitting on the shelf unused for many years as it was made wrong.
I currently have a NOS Triumph pre-unit clutch basket I bought a few months ago still wrapped in paper that the bearing race was ground too big by about .012". So now I know why it was NOS after 50 years. Also have a NOS BSA M21 output gear where the splines were made wrong and the drive chain sprocket won't fit.