Renthal Rear Sprocket 38 Tooth Silver for Honda TRX 450ER 2006-2009: Automotive. Buy Renthal Rear Sprocket 38 Tooth Silver for Honda TRX 450ER 2006-2009: Sprockets - ✓ FREE DELIVERY possible on eligible purchases. Replacement aluminum rear drive sprocket. 66% lighter than comparable steel sprockets . Comparable lifespan to much heavier sprockets . 7075 T-6 aluminum alloy . Self-cleaning chain grooves . Fits OEM bolt mounts . Ultralight Rear Sprockets start their lives off by getting CNC machined from 7075 T-6 aluminum, an alloy that is prized for its strength and wear resistance. A near perfect material for sprockets. The alloy is light weight, and with 's drilled patterns, the Ultralight weighs up to 66 percent less than comparable steel sprockets while retaining a comparable lifespan. The material isn't the only thing that promotes longevity. Self-cleaning cuts are machined into each chain groove to clear away mud and debris from sensitive wearing surfaces, so both the sprocket and chain are kept clean of abrasive particles. There's almost no downside to putting a Rear Sprocket on your motorcycle or ATV. . . .