The Triumph Rocket III Classic front turn signal bulb uses a 5008 size, while rear turn signal bulbs utilize either 5008 or 232 sizes. The replacement chart covers 2006 through 2009 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 5008 is a single-filament bulb with a BA15s bayonet base, rated at 12V. It is classified as a lower wattage variant of the 1156 bulb and conforms to ANSI standards for the US and Canadian markets.
The 232 is a festoon-type bulb with an SV8.5 base, rated at 12V and 3W. It also conforms to ANSI standards for the US and Canadian markets. Festoon bulbs are cylindrical in form and seat by pressing between two spring contacts rather than using a twist or bayonet mechanism.
The Triumph Rocket III Classic uses the 5008 bulb for both front and rear turn signals across the 2007-2009 model years, with the front position using this bulb across all four years covered by the specifications.
The 2006 Triumph Rocket III Classic rear turn signal takes the 232 festoon bulb rather than the 5008. This makes the 2006 rear position the only application in these specifications that does not use the 5008.
Because the 5008 uses a BA15s bayonet base and the 232 uses an SV8.5 festoon base, the two bulb types are not interchangeable. Substituting one for the other is not physically possible without modification to the socket.
The BA15s base on the 5008 is a single-contact bayonet fitting, which is distinct from the dual-contact BA15d base. Using a dual-contact variant in a single-contact socket would result in incorrect fitment.