Bottom Bracket and Cranks
Cleaned and polished the skate bike bottom bracket and cranks. From the beginning this was going to be the toughest part to replace. The bottom bracket (BB) is an old British/I.S.O. 1.370″ X 24 tpi threading with a shell width of 68 mm. The size on the spindle is listed as 3S but does not match any I can find. Fortunately the corrosion is not too bad. I wire brushed the parts. The most corrosion is on the locking ring which should not be hard to replace. I am going to mount them and use a grease finish to protect the raw metal. The skate bike will not be exposed to rain so the covering should provide the necessary protection.
British/I.S.O. 1.370″ X 24 tpi threading
Shell width of 68 mm
Spindle width: 147mm A: 42mm B: 53mm C: 52mm
Adjustable cup on the left, fixed on the right
Sprocket 36 teeth