The Triumph Rocket III Roadster uses 232 and 5008 bulb sizes for both front and rear turn signal applications. The replacement chart covers 2011 to 2018 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 Triumph Rocket III Roadster front and rear turn signals use two bulb types across model years: the 232 and the 5008, both of which conform to ANSI standards recognized in the US and Canada.
The 232 is a festoon bulb with an SV8.5 base, rated at 12V and 3W. Festoon bulbs are cylindrical in shape and make contact at both ends rather than through a base socket, which distinguishes them physically from standard bayonet-mount bulbs.
The 5008 is a single-filament bulb with a BA15s bayonet base, rated at 12V. It is a lower wattage variant of the 1156 bulb, meaning it shares the same base type but draws less power, making the two non-interchangeable despite their physical similarity.
For the front turn signal, the 2017-2018 model years use the 232, while 2011 and 2013-2014 use the 5008, and 2012 uses the 232 and 2016 uses the 5008.
For the rear turn signal, the 2017-2018 model years use the 232, while 2012 and 2014 and 2016 use the 5008, and 2011 and 2013 use the 232.
The front and rear turn signals do not consistently share the same bulb type within a given model year. For example, the 2013 Rocket III Roadster takes a 5008 at the front and a 232 at the rear, and the 2012 model reverses that arrangement.
Because the 232 and 5008 use fundamentally different base types, an SV8.5 festoon socket and a BA15s bayonet socket are not physically compatible, making cross-substitution between the two bulbs impossible without modification.
The wattage difference between the 232 at 3W and the 5008, which operates at a lower wattage than the 1156's 26.9W, means that replacing one with the other would also affect circuit load, which can interfere with turn signal flash rate on vehicles using load-sensitive flasher relays.