PBI USA Rear Sprocket for the Honda Grom for upgraded 428 chain is manufactured from aircraft quality 7075 T651 Plate Aluminum. Harder than steel and far lighter to save on unsprung weight. A division of Chris Products, Made in USA!
A 428 Chain is required to run this sprocket on a Honda Grom.
PBI Sprockets Aluminum Honda Grom 125 Rear Silver Sprocket - 428 Chain. 428 Chain is recommended for Honda Groms with higher displacement engines
The stock rear sprocket size on the Honda Grom is 34 tooth. You can go up to 35t, 36t or 37t to increase your acceleration at the expense of top end speed. If you go down to the 31t, 32t or 33t you can get a higher top end speed at the expense of acceleration. A few rules of thumb with gear ratios for sprockets are as follows:
- Drop teeth on front/add teeth to rear = increased torque, increased acceleration, wheelies, racetracks with short straights
- Add tooth on front/reduce teeth on rear = increased top end speed, open road cruising, lowers RPMs, better gas mileage, tracks with long straights
- 1 down on the front is like adding 3 teeth on the rear
- The bigger the rear sprocket, the lower the gearing and the faster the acceleration
