Sprint Filter P08 Air Filter for Road & Track – Royal Enfield Goan Classic 350 (2025–2026) CM231S

The Goan Classic 350 is listed here for 2025 and 2026, which makes it the newest name on this page. The element underneath it is not new at all. Sprint Filter catalogues the CM231S against five machines in this family, the earliest of them running from 2021, so a recently introduced motorcycle inherits an existing part rather than waiting for one to be drawn for it. Nothing on the air side of this bike has to be treated as an open question.

Key Features

• Woven polyester, one dry layer, rated 80 µm and 5,050 l/m²/sec for road and track use
• Completely dry in service — no oil to soak in, no film to be drawn onto the intake sensors
• Roughly twice the filter surface of other performance elements, inside the series airbox
• Fills the standard housing in place of the paper panel: no modification and no remap
• Retains 93.13 % of 100-micron particles, where four-layer oiled cotton managed 76.42 %
• Serviced with compressed air and kept for the life of the motorcycle; two-year warranty

A new motorcycle with a known part

Two model years is not long for owners to build up a feel for what a machine does to its air filter — how quickly the element loads, what the roads leave behind, when it is worth opening the box. The part itself does not carry that uncertainty. The same element has been sitting in this airbox since 2021 on other motorcycles in the family. That does not tell a Goan Classic owner how dusty their own route is, and nothing can. It does mean the component itself is a settled question from the first service onwards.

Choosing the medium once

The P08 is the standard medium, and the specification behind it is a trade rather than a rank. Finer media hold back more and pass less: the P14 non-woven listed for this airbox reaches 14 µm at 1,800 l/m²/sec, against 80 µm at 5,050 for the P08. None of them is an upgrade in the ordinary sense, and none of them adds power — a drop-in element does not make a standard 350 single noticeably stronger, whichever cloth is in it. For sealed roads and mixed weather the 80 µm P08 is the finished answer rather than a first step.

Care and cleaning

Service means compressed air, applied to the clean side so the dust is pushed back out of the weave instead of further into it. If the element has picked up oil mist rather than dust, wash it in lukewarm water with a mild detergent and rinse until the water is clear. Dry it in open air only: heat and flame destroy polyester, and a damp element belongs nowhere near the airbox. Nothing is oiled at any stage. The CM231S maintenance sheet is in the Downloads tab.

Fitment & Compatibility

For the Royal Enfield Goan Classic 350 of 2025 and 2026. The four other machines on this part number are the Bullet 350 (2023–2026), the Classic 350 (2022–2026), the Hunter 350 (2022–2026) and the Meteor 350 (2021–2026). The full list is in the Fitment tab.