Harley-Davidson XL1200R Sportster 1200 Roadster Brake Bulb Size

Harley-Davidson XL1200R Sportster 1200 Roadster uses a 3157 bulb size for brake applications. The replacement chart covers 2004 through 2008 model years 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.

Bulb Size by Year Range

Years	US Type	EU Type	Shop
2004-2008	3157	P27/7W	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157	Check Price

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Additional Notes

The Harley-Davidson XL1200R Sportster 1200 Roadster uses the 3157 bulb for the brake light across all listed model years, spanning 2004-2008.
The 3157 is an ANSI-standardized bulb type, meaning its specifications are governed by a formal industry standard recognized in both the United States and Canada.
This bulb follows the T25 wedge form factor, a designation that refers to its physical base and housing shape, which determines physical fitment into the socket.
The 3157 operates on a 12-volt electrical system, consistent with the standard automotive and motorcycle electrical architecture.
As a dual-filament bulb, the 3157 carries two separate filaments rated at 27W and 7W, allowing it to serve both a higher-intensity brake function and a lower-intensity running light function within a single housing.
The dual-filament nature of the 3157 means it is not directly interchangeable with single-filament bulbs of similar physical size, as substituting a single-filament type would disable one of the two lighting functions.