The growl of excellence. The KTM SX-F audible has become feared on racetracks across the world in the last ten years but which model should riders consider in their next investment for unadulterated fun?
By Adam Wheeler
This is a subject where KTM can roll out the orange carpet. Why? The KTM SX-F collection of three bikes is very closely linked to the motorcycles that have accumulated more FIM world championships and AMA titles in the last twenty years than any other brand. That’s a lot of competitive data, information and education that forms the basis of the production KTM 250 SX-F, KTM 350 SX-F and KTM 450 SX-F.
So, performance potential is guaranteed, and this can be felt through the refined steel chassis, the latest spec of the WP XACT adjustable suspension, the optimized ergonomics, high-level components like Brembo clutch and brake components, Neken bars, Keihin engine management and fuel injection systems and Dunlop GEOMAX tires. Then there is the advanced equipment like the dual mapping, traction control and Connectivity Unit Offroad (CUO); hardware that syncs with a portable device for even more possibilities for settings and feedback for what you are doing on the bike and when.
But, which one is the perfect motocross bike for you?
Hardened motocross riders will know well the expectations from a 250 cc engine and a 450 cc, along with the power delivery (even though this is customizable) and the sense of inertia for cornering. The 350 cc is a compromise between the step in handling and output. All three bikes have the same architecture in terms of chassis, the same fuel tank size (7.2 l), the same seat height (958 mm), suspension travel, wheelbase, brake disc diameters, wet DDS multi-disc clutch, similar compression and 5-speed gearbox with a quickshifter.
Therefore, the questions come down to: how good are you? How good do you want to be?
Without swamping you in technical specifications (these can be easily seen on the official KTM website, so click on the respective bike here to get details) here is a short outline to making your choice for a new KTM SX-F.
When should I choose a 250 cc motorcycle?
Those throttling their first meters into motocross will relish the relatively easier power-to-weight ratio of the KTM 250 SX-F. The chromoly steel frame and (aluminum-reinforced polyamide subframe) will give more agility and maneuverability across terrain and even though the weight difference between the bike and its larger brothers is negligible (101 kg and 102.6 kg dry) it is more forgiving on the throttle if you enter a potential tricky moment on track. The KTM 250 SX-F might be the smaller sibling in the family but the prized drive from the 26.1 kg motor, combined with the litheness (the anti-squat concept) and immense pedigree means it can be pushed as hard as anybody can go.
Oh, don’t forget that the KTM 250 SX-F is also KTM’s most decorated motorcycle ever. The first edition claimed the inaugural MX2 world championship in 2004 and the technical base has since added 16 titles with eleven different riders, most recently the 2025 MX2 crown (and the 2025 250SX East #1 plate). Holeshots galore. You won’t find a more READY TO RACE package if victory is your thing.
The KTM 350 SX-F vs. the KTM 450 SX-F
Back in 2015, KTM re-engineered the KTM 450 SX-F to become the motocross flagship that it is now. Until that iteration came along then the KTM 350 SX-F was a best-selling premier class model that matched the usable power of the current 450s but with the corner speed ability of the 250s. The KTM 350 SX-F was seen as the antidote to the demanding technical direction of the 450s at the start of the last decade, and the five consecutive MX1 championships (now ‘MXGP’) achieved by Tony Cairoli between 2010-2014 proved the theory correct as KTM harried into a gap that no other manufacturer was prepared to exploit. Today the KTM 450 SX-F has been slimmed and resculpted to represent a peak of off-road engineering but the KTM 350 SX-F endures for the same reasons that it prospered upon its launch: the prime sweet spot between the quarter-liter engine and the half. A category of its own.
The KTM 350 SX-F will appeal to larger-sized riders that might want more grunt than the 250 cc edition but with the mass centralization feeling similar to a 250 that makes it noticeably lighter on the arms against the push and pull of the 450.
Why should I choose a 450 cc motocross bike then?
The big brother itself has come a long way in the last decade. Acclaim in MXGP (five titles with three riders) and AMA SX (six championships with three different racers) proved that KTM expertly harnessed and curated the output of the single cylinder ‘monster’ into a chassis that could help that energy get into the ground, provide stability but also turn on a dime. Like the 250 and the 350, the KTM 450 SX-F engine platform has transitioned into other disciplines: such as the KTM 450 RALLY REPLICA for Dakar Rally purposes. The mix of rideability and all the ‘horses’ a rider could want means the KTM 450 SX-F should not be taken lightly and will need either sizeable skill or competent physicality to make the most of its deep performance.
The KTM 450 SX-F allows maximum configuration. Not only with the same WP Suspension equipment but the CUO is a clever way to tweak the shock to suit different tracks and climates and also dial-in the engine curve, while saving everything to presets. The KTM RIDER section of the KTMConnect app means the CUO can help with line selection and analysis; almost like a personal ‘coach’. This asset will be especially appreciated on a lion like the KTM 450 SX-F where everything is possible.
One more thing. For really dedicated race fans then the recent KTM SX-F FACTORY EDITIONS (for the 250 and the 450) takes the standard KTM SX-F and adds a host of KTM PowerPart upgrades for protection, customization and performance (as an example factory DID wheels, Hinson clutch clover and an Akrapovic slip-on exhaust). The Red Bull KTM Factory Racing livery is another touch for that extra slice of exclusivity you might want on track.