The gearbox, or “countershaft” sprocket is important as it connects the primary drive to the final drive. Gearbox sprockets are available in different sizes to accommodate varying needs and riding conditions.
The 18 Tooth gearbox sprocket is compatible with the 5/8 x 3/8 530 chain. Changing to an 18t sprocket from a 19t will result in a lower gear ratio through all four gears. Made in the UK.
The gearbox sprocket is fitted to the main shaft of the transmission. It transmits power from the primary drive to the rear sprocket. Must be used with a 530 chain.
The sprocket is fitted to the splines of the high-gear assembly and retained with a tab washer and large nut. The clutch assembly must be removed to access the gearbox sprocket.
We also stock 17T, 19T & 20T sprockets.