Sprint Filter P08 Air Filter for Road & Track – BMW R 1250 RS (2019–2023) PM142S

Sprint Filter specifies this element for the life of the motorcycle. On a small machine that is a modest promise. On a BMW boxer it is not: these engines are routinely ridden to very high mileages and are usually passed on rather than scrapped, so the phrase has to cover a working life measured in decades and across several owners. Read that way, the PM142S is less a performance part than a decision about how one line of the maintenance schedule is going to behave for the rest of the motorcycle's existence.

Key Features

• Dry polyester weave, single layer, with no oil at any point in its service life
• An aperture of 80 µm at 5,050 l/m²/sec of rated flow — Sprint Filter's road and track medium
• Polyester thread from ø 22 microns; the opening in the weave is the separate, larger number
• Roughly twice the filtering cloth of other performance elements, inside the unchanged housing
• Exchanges directly for the paper panel with no work on the airbox and no remap
• Cleaned instead of replaced, specified for the motorcycle's life, two years of warranty

The item that stops coming back

Almost everything on a service schedule repeats. Oil, filters, plugs, brake fluid, pads: each is bought again on a rhythm, and the rhythm is what actually costs. The air element is the unusual entry, because a woven panel can be brought back to its condition rather than replaced, and the tool for the job is an air line rather than a part number. Over the sort of distance a 1250 boxer covers, that turns a repeating line into a single one. It is a real saving and a small one. What it is not, and this deserves stating, is a power gain — the standard RS will not feel any stronger for it.

What it has to survive

A part specified for the life of a motorcycle ought to be honest about how it can be lost, and the answer is usually not dust. Polyester is undone by heat, which is why it is dried in air and never against a radiator or a flame, and it can be damaged by rough handling around its sealing edge. Neither of those is an ageing process; both are events. Barring them, the medium filters the way it filtered at the start, holding 93.13 per cent of 100-micron test particles in the manufacturer's comparison against 76.42 per cent for four-layer oiled cotton.

Care and cleaning

Blow the element through with compressed air, from its clean face outwards, and the ordinary service is complete. For anything the air leaves behind, wash it in tepid water with a mild detergent and rinse until the water runs clear. It then dries fully in open air — nothing warmer, nothing quicker — and goes back dry, with no oil or dressing of any kind. The servicing instructions are in the Downloads tab.

Fitment & Compatibility

Made for the BMW R 1250 RS built from 2019 to 2023, replacing the standard element in the unmodified airbox. Nine machines carry this part number between them; each is listed with its model years in the Fitment tab.