The Triumph Rocket III Roadster uses a 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers vehicle production spanning 2011 to 2018 with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Triumph Rocket III Roadster uses the 9003 bulb for both high beam and low beam headlight positions across the 2011-2018 model years, with 2015 absent from the listed fitment data.
The 9003 is an ANSI-standardized bulb type recognized in the United States and Canada, meaning it conforms to a defined set of electrical and physical specifications shared across manufacturers.
This bulb is a dual-filament halogen type, which allows a single unit to serve both the high beam and low beam functions within one housing, explaining its use in both headlight positions on the Rocket III Roadster.
The 9003 operates at 12 volts and draws 60 watts on the high beam filament and 55 watts on the low beam filament, figures that reflect the standard power demands of halogen headlight technology.
The base type of the 9003 is P43t, a designation that refers to the physical connector and mounting interface of the bulb, which must match the socket in the headlight housing for proper installation.
The 9003 bulb is functionally equivalent to the H4 bulb used in international markets, though the two designations originate from different standardization systems and may carry minor physical differences that affect direct interchangeability.
Because the same 9003 specification applies to both beam positions across all listed years of the Rocket III Roadster, a single replacement bulb type addresses the full headlight assembly.