THIS IS A 18 TOOTH 420 PITCH SPROCKET TO FIT 17mm SHAFT. BIGGER FRONT SPROCKET ADDS SPEED IN EACH GEAR AND MORE TOP SPEED. I ALSO HAVE 428 & 20mm SPLINE SPROCKETS LISTED. PLEASE CHECK ALL DIMENSIONS PRIOR TO PURCHASE AS REFUNDS ARE NOT GIVEN ON P&P. THIS SPROCKET WILL GET CLOSE TO THE CASING.

SPROCKET PITCH CALCULATION (JUST MEASURE YOUR SPROCKET). 6mm THICK = 420 PITCH. 7mm THICK = 428 PITCH