Yes — quality carbon fiber parts resist UV yellowing, but only when the clear coat is engineered for it. Bestem's carbon fiber parts for the Harley-Davidson Low Rider ST use a proprietary UV-resistant coating rated for roughly 3,000 hours of UV exposure — about three times the ~1,000-hour rating of a standard OEM clear coat — and every part carries a lifetime warranty against sun-ray yellowing.
Bestem UV-resistant coating: ~3,000 hours of UV exposure. Standard OEM clear coat: ~1,000 hours. Warranty: lifetime, against sun-ray (UV) yellowing.
Why do carbon fiber motorcycle parts turn yellow in the sun?
Yellowing isn't a flaw in the carbon itself — carbon fiber is inherently UV-stable. The amber tint and cloudy haze riders see on older carbon fairings come from the resin system and the clear coat sitting on top of the weave. Ultraviolet radiation breaks down the polymers in standard clear coats, and as the coating degrades it ambers, hazes, and dulls the weave underneath.
The failure point is almost always the coating, not the part. Budget wet-lay parts finished with generic clear coat can start showing sun-ray yellowing at around 1,000 hours of UV exposure — the same ballpark as most standard OEM clear coats. That's why two carbon parts that look identical on day one can look completely different after a couple of seasons parked outside.
How does Bestem build UV resistance into Low Rider ST carbon parts?
It starts with aerospace-grade construction
Every Bestem part starts as 100% pre-preg Toray carbon fiber, cured in an autoclave inside matched-metal molds. That is an aerospace-grade process — not hand-laid, wet-lay, or resin-infused — and it matters for UV stability because pre-preg carbon has tightly controlled resin content. There are no resin-rich pockets to amber unevenly, and the surface the clear coat bonds to is consistent across the entire part.
This 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 — backed by more than 20 years of carbon fiber manufacturing experience (since 2005) and ongoing work as an OEM carbon supplier to car and motorcycle manufacturers.
A proprietary UV-resistant clear coat, rated to ~3,000 hours
Bestem's proprietary UV-resistant coating is engineered specifically to shield the carbon weave from sun-ray yellowing. It is rated for approximately 3,000 hours of UV exposure — roughly 3× longer than the ~1,000 hours typical of standard OEM clear coat — before the sun can amber the finish. For a Low Rider ST that lives outside, commutes daily, or does long highway miles, that difference is the whole game.
Backed by a lifetime warranty against UV yellowing
Because of that coating, Bestem carbon fiber parts carry a lifetime warranty against sun-ray (UV) yellowing. It is a standing claim, not a marketing line: if the finish yellows from sun exposure, the warranty covers it.
Which carbon fiber parts are available for the 2023 Low Rider ST?
Bestem's Low Rider ST (FXLRST) lineup covers the most sun-exposed bodywork on the bike. All five parts are twill-weave, 100% pre-preg Toray carbon, autoclave-cured in metal molds, and finished with the 3,000-hour UV-resistant coating: