BMW Motorcycle R1150RS front turn signal bulbs measure 12496 and PY21W in size, while rear turn signal bulbs measure P21W in size. The replacement chart covers 2001 to 2004 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.
The PY21W is the front turn signal bulb for the BMW Motorcycle R1150RS across the 2001-2003 model years. It follows the ECE standard used in Europe and worldwide markets.
PY21W bulbs produce an amber output natively, which is built into the glass envelope rather than achieved through a colored lens. They operate at 12V and 21W with a single filament and mount via a BAU15s bayonet base.
The 2004 R1150RS front turn signal uses the 12496 instead of the PY21W. The 12496 is a Philips/Osram part number designating a 12V halogen bulb for specialty applications.
Because the 12496 and PY21W are distinct bulb types, the 2004 front turn signal position is not directly interchangeable with the 2001-2003 front turn signal position without confirming socket and output compatibility.
The P21W is the rear turn signal bulb for the R1150RS across all four model years covered, spanning 2001-2004, making it the only rear turn signal specification listed.
P21W bulbs are single-filament signalling bulbs operating at 12V and 21W. They use a BA15s bayonet base, which has two pins set symmetrically, distinguishing it from the offset BAU15s base of the PY21W.
The BA15s base of the P21W and the BAU15s base of the PY21W are physically incompatible with each other. Substituting one for the other in the wrong socket is not possible without modification.
Both the PY21W and P21W share the same 12V operating voltage and 21W power rating, though their base types and intended signalling functions differ.