The Bestem carbon fiber sprocket cover (SKU CBYA-FZ9-SPC-T) fits every Yamaha FJ-09 model year — 2015 through 2017 — and replaces the stock plastic countershaft cover with 100% pre-preg Toray carbon fiber, autoclave-cured in matched-metal tooling and finished in a twill weave under a UV-resistant clear coat. It bolts directly to the factory mounting points with stock hardware, no drilling or trimming required.
Will a carbon fiber sprocket cover fit the Yamaha FJ-09?
Yes. The FJ-09 shares Yamaha's 847cc CP3 triple platform with the FZ-09/MT-09, so the front sprocket (countershaft) area is identical across the family. This one cover fits the FJ-09 (2015–2017) as well as the FZ-09/MT-09 (2014–2019), the XSR900, and the Tracer 900. Because it is molded on matched-metal tooling rather than hand-formed, the mounting holes and perimeter follow the factory geometry — it installs with the original bolts and sits flush against the crankcase like the OEM piece.
Why replace the stock FJ-09 sprocket cover with carbon fiber?
The factory sprocket cover is injection-molded plastic. It does the job, but it scuffs, it dulls, and it looks out of place once you start adding carbon elsewhere on the bike. A carbon fiber replacement gives you three practical gains:
- Stiffness: Pre-preg carbon is far more rigid than ABS plastic of the same thickness, so the cover holds its shape and resists vibration over time.
- Appearance: A deep twill weave under a gloss clear coat matches other carbon parts on the bike — something painted or wrapped plastic never quite does.
- Durability: The sprocket area lives in a constant bath of chain lube fling and road grit. Carbon wipes clean without hazing or staining the way textured plastic does.
How is the Bestem sprocket cover made?
Every Bestem part starts as 100% pre-preg Toray carbon fiber — the resin is impregnated into the weave at the factory under controlled conditions, not brushed on by hand. The layup is vacuum-bagged into matched-metal molds and cured in an autoclave under heat and pressure, which forces out voids and produces a consistent, fully compacted laminate. This is an aerospace-grade process, not wet-lay or resin infusion.
It is the same autoclave-plus-100%-pre-preg construction that premium European carbon makers such as Ilmberger built their reputation on — Bestem uses that same technology and adds a superior UV-resistant coating on top. Bestem has manufactured carbon fiber since 2005 and supplies OEM carbon parts to car and motorcycle manufacturers, so this is production tooling and process control, not a garage layup.
Will a carbon fiber sprocket cover turn yellow in the sun?
UV yellowing is the single most common complaint riders have with carbon fiber parts: the clear coat ambers and clouds after enough sun exposure. Standard and OEM clear coats typically begin to yellow after roughly 1,000 hours of UV exposure. Bestem's proprietary UV-resistant coating is rated to approximately 3,000 hours — about three times longer before any sun-ray yellowing appears. Because of that coating, this sprocket cover carries a lifetime warranty against UV / sun-ray yellowing. On a part that sits low on the bike catching direct sunlight at every stoplight, that coating is doing real work.
How do you install a sprocket cover on the FJ-09?
Installation takes about 10–15 minutes with basic hand tools:
- Remove the stock cover's mounting bolts and pull the plastic cover off.
- Clean the sprocket area — this is the best opportunity you'll have to degrease built-up chain lube fling.
- Set the carbon cover in place and reinstall the factory bolts by hand.
- Snug the bolts evenly. Do not overtighten — carbon needs firm clamping, not maximum torque.
While the cover is off, it is a good time to check chain slack and sprocket tooth wear.
Which other FJ-09 carbon parts match this twill weave?
The sprocket cover is finished in the same 2×2 twill weave as the rest of the Bestem FZ-09/MT-09/FJ-09 line, so parts installed side by side read as a matched set. The two most natural companions, both sitting in the same area of the bike, are the carbon fiber chain guard (CBYA-FZ9-CGD-T) and the carbon fiber clutch cover (CBYA-FZ9-CLC-T).
A note on availability: this sprocket cover is a special-order item. Most Bestem parts are stocked in the Atlanta, GA warehouse and ship daily worldwide, and Bestem staff answer the phone live every business day — call to confirm current lead time on this part before ordering.
FAQ
Does the Bestem sprocket cover fit all FJ-09 years?
Yes. It fits the 2015, 2016, and 2017 Yamaha FJ-09, and because the platform is shared, it also fits the FZ-09/MT-09 (2014–2019), XSR900, and Tracer 900.
Do carbon fiber motorcycle parts turn yellow in the sun?
Standard clear coats can begin to amber after about 1,000 hours of UV exposure. Bestem's proprietary UV-resistant coating is rated to roughly 3,000 hours — about three times longer — and every part carries a lifetime warranty against UV / sun-ray yellowing.
Is this real carbon fiber or a carbon-look overlay?
It is 100% pre-preg Toray carbon fiber, autoclave-cured in matched-metal molds — full structural carbon through the entire part, not a hydro-dip, wrap, or fiberglass part with a single cosmetic carbon layer.
How long does installation take?
About 10–15 minutes with basic hand tools. The cover bolts to the factory mounting points using the stock hardware, with no drilling, trimming, or modification.
Is the FJ-09 sprocket cover in stock?
This part is a special-order item, so lead time can vary. Bestem answers the phone live every business day and can confirm availability before you order; most other Bestem parts are stocked in the Atlanta, GA warehouse and ship daily worldwide.