Brake Drum Rear Wheel 26TPI 60 mm long usable f. 16H, Mod.18, Mod. 19, Mod. 50, ES2, Big 4, Atlas and early Commando (not late Commando) all Norton Pre Commando and Early Nortons
AJS Piston 498 ss SV. 1928-30. K9. M9. R9 STDSTD = 84 mm Compression hight 1 29/32”Gudgeon pin diameter 11/16”Piston Clearance 0.12mm or 45thou incl. Gudgeon Pin, Piston Rings and CirclipsPlease look at all pictures