Sprint Filter P08 F1-85 Air Filter for Racing – Triumph Street Scrambler (2016–2026) PM174S F1-85

An air filter is not specified for the average kilometre, because engines do not wear on averages. A year that is ninety per cent tarmac and ten per cent dry gravel does not hand the airbox a mildly dusty year; it hands it a few genuinely dusty hours in which most of the season's particle load arrives at once. Whatever medium is fitted during those hours decides how much of it gets through. That is why the Street Scrambler deserves a different answer than the rest of its family, and why the Sprint Filter P08 F1-85, at 85 µm against the standard P08's 80 µm, moves in the wrong direction for it.

Key Features

• Coarser by design: 85 µm at 15,000 l/m²/sec, roughly three times the standard P08 rating
• That flow is not granted for free — it is bought with filtration
• Dry racing polyester with no oil in it: dust finds no tacky film to stick to, and none reaches the sensor
• Roughly double the filtering surface other performance filters offer
• Straight replacement in the standard airbox, with no modification and no remap
• After a dusty ride, compressed air on the spot; the element is washable and goes back in

Specify for the worst hour, not for the year

Averages are a comfortable way to think about riding and a poor way to choose a filter. The gravel forest road, the unsurfaced car park at a rally, the dry farm track in August — those hours are short and carry a particle concentration that ordinary tarmac never reaches, and the element chosen for the other ninety per cent is still the one in the box when they arrive. Choosing for the worst hour costs little on the good days: a finer weave passes less air, and a Bonneville twin at everyday revs is nowhere near asking for what even the road medium supplies.

The direction this machine actually needs

Sprint Filter build this element in several media, and they form a line rather than a ranking: the P08 at 80 µm and 5,050 l/m²/sec for road and track, the P14 at 14 µm and 1,800 l/m²/sec for dust and long distance, the T12 at 7 µm and 560 l/m²/sec for extreme and off-road use. Every step buys retention and pays for it in flow. A Street Scrambler used the way its high pipe suggests wants to move down that line, not up it: the P08 for mostly sealed roads, the P14 once unsealed surfaces are a regular part of the route. The F1-85 earns its place on a machine that is raced and stripped by operating hours.

Care and cleaning

Whichever medium ends up in the box, the routine is identical. Compressed air goes in at the clean side and works outwards; water with a mild detergent handles what the air line will not shift, rinsed until the water runs clear. The PM174S F1-85 then dries fully in open air — never with heat, never over a flame — and is refitted dry. The maintenance sheet is in the Downloads tab.

Fitment & Compatibility

Made for the Triumph Street Scrambler, 2016–2026. The same 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.