KTM's latest 250 SX-F and 450 SX-F Factory Editions are a preview of the engineering headed for the wider 2028 SX range. Both 2027 editions have redesigned frames, WP XACT closed-cartridge spring forks and revised ergonomics. The 250's engine is the larger departure, with a new intake, valve train and a higher operating ceiling.
The 250 engine changes
The quarter-litre uses an oval throttle body and intake ports, top-feed injection and a completely redesigned valve train. Compression is 15.5:1 and the rev limit is 14,500rpm. KTM has moved the engine 2.3mm higher in the frame as part of the packaging change.
450 output and shared controls
The 450 claims 63.8hp (47.6kW) at 10,000rpm and 52Nm at 7,000rpm. Both bikes gain a new exhaust and engine-management updates, with a faster ECU and revised gear-dependent mapping. KTM has also worked on gearbox weight, shift quality and quickshifter operation; these remain manufacturer development claims until the bikes are tested.
A new chassis and riding position
New steering heads, engine mounts and stiffness targets are part of the chassis redesign. The aluminium subframe is lighter, wheelbase adjustment has more scope, and the triple clamps are new. A slimmer profile, revised seat and footpeg surfaces aim to give riders more room to move and a better contact area with the bike.
The component list includes Brembo brakes, EXCEL wheels with a revised spoke arrangement, lighter NEKEN handlebars, ODI lock-on grips and a Selle Dalla Valle seat cover. WP Pro Components supplies the triple clamps and start device. The hour meter is easier to reach, and changes to the airbox, cooling and service access support regular race preparation.
Availability and the 2028 connection
The two Factory Editions are offered through authorised dealers in international markets, with country availability varying. US and German prices and delivery dates are unconfirmed. KTM says the technical direction carries into its forthcoming 2028 SX line.
US and European pricing is still to be confirmed.