Description THIS IS A 13 TOOTH 428 PITCH SPROCKET TO FIT 17mm ENGINE SHAFT. BIGGER FRONT SPROCKET ADDS SPEED IN EACH GEAR AND MORE TOP SPEED. I ALSO HAVE 420 & 20mm SPLINE SPROCKETS LISTED. PLEASE CHECK ALL DIMENSIONS PRIOR TO PURCHASE AS REFUNDS ARE NOT GIVEN ON P&P. PLEASE CHECK CAREFULLY . SPROCKET PITCH CALCULATION (JUST MEASURE YOUR SPROCKET THICKNESS). 6mm THICK = 420 PITCH. 7mm THICK = 428 PITCH ORDER BEFORE 12 MIDDAY ON MONDAYS OR AFTER BANK HOLIDAYS, 2PM TUESDAY TO FRIDAY FOR SAME DAY DISPATCH. WE ONLY DISPATCH ORDERS MONDAY TO FRIDAY. If you have any questions, please call us on 01789766777. Phone opening hours 10am-2pm Monday to Friday
