OSAKI REAR SPROCKET for HONDA GROM 125 - 31 Tooth Balance your engine power with transmission adjustments! Affordable and easy to install rear sprockets from Osaki Steel construction makes it more durable than aluminum sprockets! By changing both your front and rear sprockets, you can find the combination that gives you the gear ratio that works best for you. With the right combination of rear and front sprockets you can improve acceleration and/or top speed!