ProTaper Race Spec Aluminum Sprocket
MSRP: $69.95
$55.96
Exact Fitment Guarantee
The ProTaper Race Spec (RS) Aluminum Rear Sprocket is an ultralight, high-precision rear sprocket engineered to deliver minimum rotating mass, razor-sharp throttle response, and race-winning durability for competitive motocross and off-road motorcycles. Reducing unsprung rotating mass at the rear wheel provides an immediate mechanical advantage: the rear suspension reacts faster over high-speed chop, and engine power spools up with crisp urgency out of corners.
CNC-machined in the USA from premium 7075-T6 aerospace-grade aluminum alloy, the RS sprocket features an optimized CAD-engineered cutout pattern that achieves maximum structural rigidity while shedding every unnecessary gram of weight. The sprocket teeth undergo a specialized deep-tooth profile machining process that ensures seamless chain engagement and minimizes friction. Angled mud-relief grooves are machined into the base of every tooth valley on both sides of the sprocket, using centrifugal force to actively eject wet clay, sand, and mud away from the chain contact path. The sprocket is finished with a hard-anodized coating that resists abrasive wear and corrosion.
- Material: 100% CNC-machined 7075-T6 aerospace aluminum alloy
- Tooth Profile: Deep-tooth CAD radius for optimal chain roller contact
- Mud Channels: Angled bilateral mud-relief grooves on both inner and outer faces
- Finish: Anodized protective coating with laser-etched tooth count
- Weight: Approx. 280-320 grams (depending on tooth count)
### Step-by-Step Installation & Safety Protocols Installation requires high-strength metric sprocket bolts and Fuji metal-locking nuts. Clean the hub face thoroughly. Place the ProTaper RS sprocket against the wheel hub with the engraved tooth count facing outward. Insert new tapered sprocket bolts with a dab of blue Loctite on the threads. Tighten the locking nuts in a progressive diagonal sequence to the motorcycle manufacturer's specified torque (typically 32 to 35 Nm). Always verify that the sprocket sits completely flat against the hub shoulder without gaps.
### Maintenance & Wear Indicators Maintenance includes inspecting the aluminum teeth for hooking, shark-finning, or lateral bending. When teeth exhibit visible directional wear or when replacing your drive chain, replace the sprocket immediately to prevent chain damage.
Frequently Asked Questions
Q: Why are mud grooves important on an aluminum rear sprocket?
A: Mud grooves provide an escape channel for packed dirt, clay, and sand. Without mud grooves, debris packs tightly into the tooth valleys, overtightening the chain and causing extreme premature wear on both the chain and sprockets.
Q: What is the benefit of 7075-T6 aluminum over standard aluminum?
A: 7075-T6 is an aerospace-grade alloy with exceptional yield strength and hardness (comparable to many structural steels) while weighing approximately one-third as much, making it the premier material for lightweight racing sprockets.
Q: How do I tell when my ProTaper aluminum sprocket needs replacement?
A: Replace the sprocket when the teeth lose their symmetrical trapezoidal shape and begin to curve forward like shark fins, or when the tips of the teeth become visibly sharpened or chipped.
Q: Can I run an O-ring chain with this aluminum sprocket?
A: Yes. The ProTaper RS sprocket is fully compatible with both non-sealed (non O-ring) and sealed (O-ring / X-ring) 520 drive chains.