Sprint Filter P08 F1-85 Air Filter for Racing – Royal Enfield Meteor 350 (2021–2026) CM231S F1-85

Of the three elements Sprint Filter builds for this airbox, the CM231S F1-85 carries the most open rating. Its 85 µm sits above the 80 µm of the standard woven medium and far above the 14 µm of the non-woven P14, and that ordering is no accident: across the range, air is bought with filtration and filtration is bought with air. A Meteor 350 that spends its days on dusty or unsealed roads therefore has a clear direction to move in, and it is the opposite of this one.

Key Features

• Dry polyester racing medium at 85 µm, rated for 15,000 l/m²/sec of airflow
• The most open of the three media offered for the Meteor 350 airbox
• Retention of 95.22 % of 100-micron particles in the manufacturer comparison
• Oil free in service, with nothing to dose and nothing to reach the throttle body
• Around twice the filtering surface of other performance elements, in the standard airbox
• Direct replacement without modification or remapping; two years of warranty

Which way the trade runs

Filtration and flow are two ends of one lever. Push it towards air and the fabric opens; push it towards protection and the air has to work harder to get through. This medium sits hard against the airflow end, which is what a race engine wants and what a dusty commute does not. Sprint Filter offers the other extreme for this same box in the P14 non-woven, with the standard woven element between them. None of the three is the upgrade; each answers a different question about the road.

What that means for a Meteor

The Meteor 350 has been in this catalogue since 2021, long enough for owners to have formed a view of what their own roads leave behind in the airbox. If the answer is a lot, the racing medium is the wrong way to go, and the outlay makes it a costly wrong way, since it asks a little over three times what the standard element asks. If the answer is a race programme, it makes sense. What it never does is add output, because a drop-in filter does not make a standard 350 single noticeably stronger.

Care and cleaning

Compressed air from the clean side, worked outwards, restores this element in normal service. If the deposit is greasy, lukewarm water and a mild detergent will shift it; rinse until the run-off is clear. Dry in open air until no moisture is left, keeping heaters and flame away from the polyester, then refit the CM231S F1-85 with nothing applied to it. The maintenance sheet lives under Downloads.

Fitment & Compatibility

For the Royal Enfield Meteor 350 of 2021 to 2026. Five machines carry this part number: with the Meteor, the Bullet 350, the Classic 350, the Goan Classic 350 and the Hunter 350. Each year span appears in the Fitment tab.