Triumph Tiger Tail Light Bulb Size

The Triumph Tiger tail light bulb uses a P21/5W size across the model line. This replacement chart covers 2002 to 2006 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.

Bulb Size by Year Range

Years	Bulb Size
2002-2006	P21/5W

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Dual-filament signalling bulb with BAY15d bayonet base. 12V, 21W/5W.	P21/5W

Other Locations

Additional Notes

The Triumph Tiger (2002-2006) uses the P21/5W bulb for the tail light position across all five model years covered in these specifications.
The P21/5W is a dual-filament bulb, meaning it contains two separate filaments within a single glass envelope. The 21W filament serves the braking or turn signal function, while the 5W filament handles the running or position light function.
The P21/5W operates on a 12V electrical system, which is standard for motorcycle applications of this era.
The bulb uses a BAY15d bayonet base. The BAY15d designation indicates an offset pin configuration, where the two retaining pins are positioned at different heights on the base. This asymmetric design prevents incorrect insertion, ensuring the two filaments are oriented to their correct circuits.
The P21/5W conforms to ECE (Economic Commission for Europe) standards, a regulatory framework recognized across Europe and numerous other markets worldwide.
Because the BAY15d base uses offset pins, it is not interchangeable with the BA15d base, which shares the same pin spacing but uses pins at equal heights. Substituting a BA15d bulb in a BAY15d socket is not possible without modification.