The Triumph Trophy SE uses a 12496 PY21W bulb size for both front and rear turn signal applications. The replacement chart covers 2013 through 2017 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 PY21W is an ECE-standardized single-filament amber bulb operating at 12V and 21W, fitted with a BAU15s bayonet base. The BAU15s base uses offset pins to prevent incorrect installation of clear bulbs in positions requiring amber output.
The 12496 is a halogen bulb designated by Philips and Osram part numbering systems for specialty automotive applications, rated at 12V. It is functionally distinct from the ECE-designated PY21W despite both appearing in turn signal positions on the Triumph Trophy SE.
On the Triumph Trophy SE, the front turn signal position uses the 12496 bulb for the 2013, 2014, and 2017 model years, while the 2016 model year uses the PY21W in that same position.
The rear turn signal position on the Trophy SE uses the PY21W for the 2013, 2014, and 2016 model years, while the 2017 model year uses the 12496 in that position.
The 2017 model year is the only year in these specifications where both the front and rear turn signal positions share the same bulb type, with the 12496 fitted at both locations.
The 2016 model year is the only year where both the front and rear turn signal positions use the PY21W at both locations.
The BAU15s bayonet base of the PY21W is not interchangeable with the more common BA15s or BAY15d bases. Substituting a bulb with a different base type would result in fitment failure or incorrect seating in the socket.