Sprint Filter P08 Air Filter for Road & Track – Triumph Street Twin (2016–2026) PM174S

The Street Twin is the Bonneville people actually ride in February. It is unfaired and often somebody's only motorcycle, and it spends the winter half of the year drawing cold, damp, salty air through an airbox that was designed for the same job in July. Cellulose is the wrong material for that diet: paper takes up moisture from humid air and gives it back slowly, and each cycle leaves it a little further from the part that was fitted. The Sprint Filter PM174S is woven polyester. It does not absorb, it is meant to be washed, and the restriction the engine pulls against in March is the one it pulled against in October.

Key Features

• Damp intake air leaves the dry polyester medium as it found it: it does not swell and it does not soften
• A calibrated 80 µm aperture, woven from polyester threads of ø 22 microns and upwards
• The filtering surface is around double that of other performance filters
• Never oiled, so there is no film to wash off and none that can reach the air sensor
• Washable, reusable, and specified to last as long as the motorcycle does
• Two years of warranty, starting at the date of purchase

A filter you are supposed to wash

There is a difference between a filter that survives getting wet and a filter that is designed to be washed. Water and a mild detergent are part of the P08 service procedure, not an emergency measure, and the element goes back into the airbox dry and at the restriction it left the factory with. For a bike that commutes through winter that matters more than any peak-power figure: the intake side stops being the part of the motorcycle that quietly ages while you are not looking at it.

When the weather is the main problem

If your riding is genuinely wet more often than it is dry, Sprint Filter offer this same element as a P037: a water-repellent dry polyester at 37 µm and 4,500 l/m²/sec, against the P08 at 80 µm and 5,050 l/m²/sec. The finer weave holds back more and flows a little less — that is the trade in both directions, and neither medium outranks the other. For year-round road use with normal winters, the P08 PM174S is the sensible default.

Care and cleaning

The air line does the regular work — held to the clean side and blown outwards, so the dirt leaves by the route it took coming in. Water and a mild detergent are there for what the air will not move; rinse until the water runs clear. Then leave the PM174S in open air until it is dry all the way through, keeping it away from heat and from any flame, and refit it dry. There is never an oiling step. The maintenance sheet is in the Downloads tab.

Fitment & Compatibility

Made for the Triumph Street Twin, 2016–2026. The same PM174S element covers five machines built around this airbox — the Bonneville T100 and T120, the Street Cup, the Street Scrambler and the Street Twin. The full list with model years is in the Fitment tab.