Sprint Filter P08 F1-85 Air Filter for Racing – BMW R 1250 R (2019–2023) PM142S F1-85

This medium exists for one state: throttle fully open, high in the rev range, held there for whole seconds and returned to again and again. That is a description of a circuit. The R 1250 R, meanwhile, is a motorcycle with no fairing on it at all. Whatever the engine might be willing to do, the rider is hanging out in the airstream holding on with two arms, and on a naked boxer the arms run out of argument long before the intake becomes the thing standing in the way.

Key Features

• The racing weave of the P08 family: dry woven polyester, never oiled at any stage
• An 85 µm aperture at a rated 15,000 l/m²/sec, the highest flow figure Sprint Filter publishes
• Retention quoted at 95.22 per cent of 100-micron test particles
• Around twice the filtering cloth of an ordinary performance element
• Direct replacement for the paper panel: the housing untouched, the mapping as written
• Washed and used again for the life of the machine, with two years of warranty from purchase

How long wide open actually lasts

On a public road the state survives a second or two between gearchanges and is then shut down by traffic, by a bend or by the law. Without a screen it closes sooner still, because speed on an unfaired machine is physical work and the work climbs steeply. The rated 15,000 l/m²/sec this cloth carries is a ceiling, not a delivery, and a ceiling is worth paying for only when something reaches towards it. The standard element for the same airbox is rated at 5,050 l/m²/sec and hands over every litre a road boxer has ever asked for.

When it is the right order anyway

Track days, and little else. If the R 1250 R spends part of its year on a closed circuit, where one throttle position is held deliberately down a straight and repeated for twenty minutes at a time, the most open weave in the range stops being decoration. What it is not is a power part: the PM142S F1-85 will not make a standard R 1250 R noticeably stronger, because a panel inside an untouched airbox is not where power comes from. It is listed at close to three times what the standard element for this housing costs, and the premium buys a rate alone — the dry polyester, the absence of oil, the air-line servicing and the design life belong to every element in the family.

Care and cleaning

Dry work in the ordinary case: an air line laid against the clean face and blown outwards, so whatever the weave caught leaves in the direction it arrived from. When road film leaves something the air will not shift, hand-warm water and a little mild detergent lift it, and the cloth is rinsed until the water stays clear. Drying happens in moving air, nowhere near a heat source or a flame, since polyester is undone by heat rather than by dirt. It goes back dry. The maintenance sheet is under the Downloads tab.

Fitment & Compatibility

Made for the BMW R 1250 R built from 2019 to 2023, as a direct swap in the standard airbox. This element is catalogued for three machines — the R, the RS and the RT of that generation — and for no GS at all; the Fitment tab gives the years for each.