Sprint Filter P08 F1-85 Air Filter for Racing – Honda CBR250RR (2017–2026) PM168S F1-85

Sprint Filter lists its racing element at much the same level whichever housing it is cut for, while a standard element is priced by the housing it fills. The arithmetic falling out of those two habits deserves stating before anything else: on the CBR250RR the racing cloth comes to more than three times the standard element, one of the steepest steps anywhere in the Honda listing. That multiple describes not this part but the small, inexpensive element it is measured against.

Key Features

• Dry polyester in racing specification: 85 µm aperture, 15,000 l/m²/sec
• Roughly three times the flow rating of the standard P08 through the very same airbox
• Retention measured at 95.22 % of 100-micron particles, against 93.13 % for the P08
• Never oiled at any stage; an air line is the whole of the service kit
• Series airbox, series ducting, series mapping — the change is internal and reversible
• Two years of guarantee on an element specified to outlast the motorcycle

Why the step looks so large on this airbox

A small housing takes little material and sells in numbers, so the element filling it sits among the cheaper things in the catalogue. The racing cloth is a different production altogether and appears at a broadly similar level wherever it is listed. Set the two beside each other on a 250 and the multiple is dramatic; do the same on a litre bike and the multiple falls closer to two, with nothing about either part having changed. The ratio is arithmetic between two prices, not a measure of what is gained.

The case that survives the arithmetic

What is gained is flow capacity, and a road-registered quarter-litre twin has no mechanism for reaching it. An insert filter does not make a standard motorcycle noticeably stronger, and this one leaves a CBR250RR exactly as quick as it was. The 85 µm aperture, meanwhile, is a deliberate step back from the standard 80 and applies to every hour the engine turns, not only the interesting ones. Where the PM168S F1-85 earns its keep is a machine run in one-make racing or regular track work, pulled and blown through between sessions, because a cloth built for that rhythm rewards it.

Care and cleaning

Service is a matter of removal. A compressor line at the clean face, moved steadily outward, brings the colour of the cloth back to something even. Anything oily the road left comes off with warm water and mild washing-up detergent, rinsed until nothing tints the run-off. After that it dries by being left alone in moving air, because heat is what polyester surrenders to first, and a hot air gun will distort a weave that then never seals as it should. Nothing is applied afterwards and nothing goes back in damp. The sheet for this element is under the Downloads tab.

Fitment & Compatibility

Catalogued for the Honda CBR250RR alone, model years 2017 through 2026, with no sister model sharing the housing. The same airbox is also served by the standard P08 and by the fine P14, which are the two alternatives worth weighing before this one. Full details in the Fitment tab.