The Triumph Street Cup uses a 9003 bulb size for both high beam and low beam headlight applications. The replacement chart covers vehicle production spanning 2017 to 2018.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9003 is a dual-filament halogen bulb, meaning a single unit contains two separate filaments: one rated at 60W for high beam operation and one at 55W for low beam operation.
The 9003 operates on a 12-volt electrical system, which is standard across most production motorcycles and passenger vehicles.
The bulb uses a P43t base, a three-pronged bayonet-style mount that physically locks the bulb into the housing and ensures correct filament alignment.
The 9003 designation follows the ANSI standard used in the United States and Canada. It is electrically and physically equivalent to the European H4 bulb, and the two are generally interchangeable in practice.
The Triumph Street Cup (2017-2018) uses the 9003 bulb for both the high beam and low beam headlight positions, with a single bulb type serving both functions due to its dual-filament design.
Because the high beam and low beam share one bulb in this application, replacing either headlight function requires the same 9003 part, with no separate bulb needed for each beam mode.