Sprint Filter P08 Air Filter for Road & Track – BMW R nineT Scrambler (2017–2020) PM109S

The high-routed exhaust and the 19-inch front wheel make a promise about terrain that most R nineT Scramblers are never asked to keep. That promise is worth separating from what the airbox actually swallows. Sprint Filter answers that question twice: the same housing is catalogued with two different media, and the Scrambler is the only variant of the range offered both of them. Choosing between them is the real decision here, and the PM109S is the road and track half of it.

Key Features

• Dry polyester weave in one layer — no oil in it new, none reapplied once it has been cleaned
• Rated flow 5,050 l/m²/sec through 80 µm openings, which is what makes this the P08 road medium
• Fibre diameter starts at ø 22 microns; the 80 µm figure belongs to the mesh, and the two differ
• About double the working surface of other performance filters, held inside the standard frame
• A straight exchange for the factory paper panel, with the housing and the mapping untouched
• Cleaned rather than bought again, for the life of the motorcycle, guaranteed for two years

What a road bike meets on a gravel road

An afternoon on a dry forest track raises far more into the air than a month of commuting, and rather less than the photographs suggest — one motorcycle, its own dust trailing behind it, nothing like the wall a following rider takes on a rally stage. It is a load that arrives in bursts and then stops. Surface area is the right answer to bursts: spread the same quantity of dust over roughly twice the cloth and the restriction it causes climbs more slowly, and an air line takes all of it back off again afterwards.

Two media for one housing

The alternative Sprint Filter lists for this airbox is the P14, a dry non-woven rated at 14 µm and 1,800 l/m²/sec and intended for dusty use. Put the two pairs of numbers side by side and the rule behind them is plain: the finer the medium, the more it retains and the less it passes. That is an exchange rather than a ranking, and the P14 is not the better filter — it is the filter for a Scrambler that is regularly in dust. For one that spends its weeks on tarmac and its weekends on loose surfaces, the P08 is the correct side of the trade. Neither will make the motorcycle noticeably quicker; no element dropped into a standard airbox does that.

Care and cleaning

Compressed air from the clean side outward is how the PM109S is regenerated, and after most rides it is all that is wanted. Grit and damp off a wet track are another matter: warm water with a mild washing-up detergent releases what the air leaves behind, and it is rinsed until nothing more comes out. Drying happens in open air alone — never against heat, never near a flame — and it goes back into the box dry and untreated. The cleaning instructions sit in the Downloads tab.

Fitment & Compatibility

Specified for the airbox of the BMW R nineT Scrambler built from 2017 to 2020, in place of the standard paper element. Fifteen machines from the air-cooled boxer range are covered by this part number, each listed with its model years in the Fitment tab.