Sprint Filter P08 F1-85 Air Filter for Racing – Triumph Bonneville T100 (2017–2021) PM174S F1-85

Before buying airflow, find out whether anything is holding any back. The check costs nothing: the standard element comes out of the airbox and you look at it. Held against a window, a fresh cellulose filter passes a surprising amount of light; one that has worked through four dusty summers passes almost none, and its restriction has been climbing quietly all along. That is the honest place to start, because the Sprint Filter P08 F1-85 is a racing medium and the T100 is not a racing motorcycle.

Key Features

• 85 µm at 15,000 l/m²/sec — the highest-flowing woven medium in the range
• That flow is bought, not given: at 85 µm the weave is coarser than the 80 µm standard P08
• Racing polyester, dry and never oiled, so nothing can travel downstream onto sensors or throttle bodies
• Roughly twice the filtering surface other performance filters have
• A direct swap into the standard airbox: no modification, no remap
• Serviced with compressed air, washable and reusable, and covered for two years

Do the ten-minute check first

If the element that comes out is grey, evenly loaded and stiff with dust, your intake really has been costing you something, and a clean filter of any Sprint Filter medium gives that back. If it comes out close to new — which on a carefully kept T100 it usually does — there is nothing there to recover, and a medium rated at roughly three times the air flow of the standard P08 will find nothing to do. That is not an argument against the part, but for choosing the medium on evidence rather than on the size of a number.

What 85 µm is a decision about

Racing accepts coarse filtration because a race engine is opened on a schedule of operating hours: whatever slipped past is found long before it turns into a bill. The 85 µm aperture is a step backwards from the 80 µm of the standard P08, taken deliberately and paid for with the three-fold jump in flow. Nobody strips a Bonneville twin between rides, so on the road that half of the bargain is never honoured. If the check says the intake needs attention, the P08 at 80 µm and 5,050 l/m²/sec is the road-and-track medium; where the roads are dusty, the P14 at 14 µm and 1,800 l/m²/sec trades the other way on purpose.

Care and cleaning

Service the PM174S F1-85 with compressed air held to the clean side and worked outwards, so that what the weave stopped leaves by the way it arrived. Water with a mild detergent takes care of the rest; rinse until the water runs clear. Then let the element dry right through in open air — heat is not an option and neither is a flame — and refit it dry. There is no oiling step. The maintenance sheet is in the Downloads tab.

Fitment & Compatibility

Made for the Triumph Bonneville T100, 2017–2021. 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.