BMW Motorcycle R1100S headlight bulbs utilize H1 size for high beam and H7 size for low beam applications. The replacement chart covers 1998 to 2005 production 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.
The BMW Motorcycle R1100S uses the H1 bulb type for high beam headlight applications across all model years from 1998-2005.
The H1 is a single-filament halogen bulb operating at 12V and 55W, fitted with a P14.5s base, and is rated under ECE standards with approval also extended to the US and Japan.
The low beam headlight position across the full 1998-2005 production span of the R1100S calls for the H7 bulb type.
The H7 is a single-filament halogen bulb operating at 12V and 55W, fitted with a PX26d base, and carries the same ECE-standard approval as the H1, including the US and Japan.
Although the H1 and H7 share identical voltage and wattage ratings of 12V and 55W, their base types differ: the H1 uses a P14.5s base while the H7 uses a PX26d base, making the two types physically non-interchangeable.
Because the R1100S uses separate bulb types for each beam function, replacing a high beam bulb with an H7 or a low beam bulb with an H1 would result in a fitment mismatch due to the differing base configurations.