2025 KTM 300 SX Review

2025 KTM 300 SX
ReviewKey FeaturesFeatures & BenefitsSpecifications

2025 KTM 300 SX 2025 KTM 300 SX


Introducing the 2025 KTM 350 SX-F…

When it comes to power-to-weight ratios, the KTM 300 SX writes the rule book. Now with learnings taken directly from the KTM Factory Racing teams, and a care package labeled “Go get ’em!”, the 2025 KTM 300 SX is engineered for one task alone – to lead from the front.





2025 KTM 300 SX Totalmotorcycle.com Key Features


Boasting the largest arsenal of 2-stroke weaponry, the 2025 KTM SX line-up has something for everyone. From the most potent 50 cc mini-crossers to the unprecedented KTM 300 SX, the KTM SX range is primed and ready to bring the noise.

After a 2-year absence, the 2025 KTM 150 SX is bringing the 150 cc designation to a table-top near you. With a lightweight chassis, and a pure READY TO RACE attitude, the KTM 150 SX is back to set a whole new benchmark.


Two years ago the 2023 KTM SX line-up grabbed the holeshot with major updates across the range. For 2025, the KTM SX and SX-F brings even more firepower to the starting gate. Armed and fully loaded with chassis updates and technological advances, the 2025 KTM SX and SX-F range has total championship domination firmly in sight.

The 2025 KTM Motocross lineup receives its updates directly from the KTM Factory Racing efforts. From a reworked frame to updated tank shrouds and new tires, this is our most advanced range of motocrossers yet.

  • Re-worked frame with updated shock mountings and front triangle, including an improved wall thickness.
  • Improved engine mounts with cut-outs to enhance chassis flex, reduce weight by 300g, maintain stability, and improve cornering.
  • Updated tank shrouds with bi-compound plastics improve radiator airflow and cooling
  • Updated chain glider design for improved mud dissipation.
  • Upgraded suspension settings at both ends in support of the updated frame and rear linkage, improving weight distribution, stiffness, and response.
  • Upgraded rear brake pedal construction for increased stiffness and resistance to bending.
  • New fuel tank roll for improved fitment, reducing frame scrubbing, and enhancing durability.
  • New Dunlop GEOMAX MX34 Motocross tires as standard.
  • Connectivity Unit Offroad is available as KTM PowerParts for the KTM SX-F line-up with a wide range of functionalities via the KTMconnect app.




In its latest update since the completely revamped 2023 KTM SX range, the 2025 KTM SX and 2025 KTM SX-F range have upped the ante when it comes to rider connection, composure, and control – along with the return of a fan favorite.
Engineered to provide riders with more control than ever before, the 2025 KTM SX and SX-F range brings a series of updates adopted directly from KTM Factory Racing efforts, making this the most READY TO RACE line-up yet.

The frame has received the most significant update share, with visible cutouts and tube-wall thickness changes around the front, engine mounts, and rear shock mounting areas. These changes have been specifically engineered to improve chassis flex characteristics and reduce weight by around 300 g while maintaining overall stability and improving cornering behavior. An updated swingarm with a machined chain glider and an updated rear brake pedal for improved durability round off updates to the frame.

New Dunlop GEOMAX MX34 Motocross tires are standard on the 2025 KTM SX and SX-F models, providing stability and control at the highest level to perform at their best. These feature a new carcass compound that improves damping and absorption, adding up to 30% longer performance. New Progressive Cornering Block Technology improves traction, grip, and mud dissipation.

At the rear, the WP XACT rear shock benefits from an updated linkage with renewed seals and smaller diameter linkage bolts. The setup is taken directly from the KTM Factory Racing Team and is optimized to benefit weight savings and stiffness parameters. To complement the updates at the rear, the WP XACT AER fork features reworked settings to account for more flex and less weight.

Ergonomically, the 2025 KTM SX and SX-F range features new tank shrouds with bi-composite plastics on the upper and lower flanks, providing a fresh, sharp, distinctive new look and improved cooling. This is supported by an updated fuel tank roll that protects the frame against wear from scrubbing and improves tank fitment. Lastly, an updated air inlet sleeve and snorkel design features on the 2025 models. This is now a 1-piece part, preventing deformation through a more robust and stiffer material design.

Above the surface, all-new graphics mirror the new design language of the tank shrouds and hint at the many small technical changes on the 2025 line-up. Full-orange bodywork, red and black in-mold graphics, and a more durable black seat bring a clean look while communicating pure, READY TO RACE intention.

2025 also sees the introduction of the Connectivity Unit Offroad, which is available as KTM PowerParts for the 2025 KTM SX-F line-up. The CUO offers various functionalities and adjustability options via the KTMconnect app. This exists as two parts: the CUO, mounted on the right upper fork between the lower and upper triple clamp, and the GPS sensor on the front fender. A CUO-compatible front fender is also available as a KTM PowerParts option.

At long last, the cherished KTM 150 SX rejoins the 2-stroke stable with much anticipation. The 2025 KTM 150 SX builds upon the foundation of the KTM 125 SX but with a significant overhaul of components. Specifically designed, modified, and rearranged for racers in pursuit of elevated performance, it offers enhanced torque and an enriched riding experience.

The 2025 KTM SX and SX-F models introduce subtle yet significant enhancements to the race paddock, offering the broadest selection of machines designed to meet the needs of every rider and racer.





2025 KTM 300 SX Totalmotorcycle.com Features and Benefits


Easy Suspension Adjustment

As always, the suspension boasts an easy tool-free setup at both ends, ensuring you chase down the podium in total control. On the rear, a hand-adjustable dual compression control allows riders to adjust high- and low-speed settings in a matter of seconds. The forks on the front end are also easily adjusted thanks to hand-adjustable clickers on the bottom of the fork shoe and top cap.


Electronic Fuel Injection

Pre-mix gets a remix across the 2-stroke KTM SX range, with Electronic Fuel Injection setting the standard. Now there’s no more fiddly jetting setup pre-race, And thanks to the Keihin EFI and reed valve case design, you can be guaranteed of laying down optimal power at any altitude, all of the time.



Electric Start

Picture this; You’re 7 laps into an absolute ripper of a race. You miss your line and end up stalling in a deep rut. But you don’t sweat it. All you do is press the starter button and you blast off again to take the final flag. This is the reality on the 2025 KTM 300 SX. Thanks to a 12.8V 2 Ah lithium ion battery is placed under the rider’s seat, a high-quality stator & pickup and super robust design, the only thing you’ll be kicking – is ass.



EFI + Power Valve

With EFI comes great rideability. Along with the electronic fuel injection and a power valve on the KTM 300 SX, allowing for more usable power throughout the rev range. Smoother power means better traction. Better traction means holeshot heaven!




The new 300 cc 2-stroke powerhouse brings a new choice of weapon into the MX Open category and provides more choice for racers looking for maximum power at the least possible weight. Along with low maintenance costs, an overall engine weight of just 52.6 lb (23.9 kg), the 2025 KTM 300 SX provides pure performance. And then some.


Selectable Maps

The 2025 KTM 300 SX features a map select switch allowing the racer to switch between 2 engine maps. Map 1 provides a linear, predictable power delivery, while Map 2 gives it the full beans with crisp, explosive power output.



Absolute Control

Get ready for a full-on berm assault. The 2025 KTM SX and SX-F machines have received major frame updates directly from Factory Racing efforts. For starters, the frame area around the rear shock mount has been updated and made more streamlined, with new engine mounts and cut-outs for improved chassis flex. The front area of the frame is also updated. with a different wall thickness than the previous model year, with renewed engine mounts. This adds up to a 300g weight saving and improved flex for better cornering.




Upgraded tank shrouds using bi-compound plastics channel air towards the radiators more efficiently, while a new fuel tank roll, makes for a tighter, more secure fitment, reducing the chance of frame scrubbing and dramatically improving durability. All this works alongside the specially-developed rider triangle, to provide unmatched knee contact and gripping surfaces – especially when standing on the pegs.


Mass Centralization

With a major emphasis placed on mass centralization, the 2025 KTM 300 SX engine is designed to centralize rotating mass for optimal operation with the chassis. This results in a lighter, more agile handling feel that simply runs rings around the competition.


Updated Suspension Settings

For 2025, the KTM SX and SX-F range has given the WP XACT AER fork and WP XACT rear shock an update. This means you’ll be lining up at the starting gate with re-tuned settings, reduced weight, improved weight distribution, and an increase in overall response.



Let’s get the technical parts out of the way first; the 48 mm WP XACT AER forks fitted to the 2025 KTM SX and SX-F line-up features a capsulated air spring and pressurized oil chamber for progressive and consistent damping, while oil and air bypasses reduce pressure peaks. In combination with the mid-valve damping system, all this provides exceptional feedback and rider comfort. The fork also boasts new settings, which not only compliment the updated frame and rear linkage, but ensures stellar performance at all levels. Speaking of settings, these are easily adjusted via a single air pressure pre-load valve, as well as easy-access click adjusters for compression and rebound. Additionally, the air pump needed to adjust the fork’s air pressure is provided as standard in the buy-pack.



Keeping things in check at the rear, the WP XACT rear shock has also undergone some changes for 2025 using settings directly from the KTM Factory Racing Teams The improved frame and shock geometry mean more ground clearance at the linkage, making it less susceptible to bottoming out. While we’re on the topic, smaller diameter linkage bolts save weight, while new linkage seals refine rear shock response and advanced damping characteristics.




An upgraded rear brake pedal finds its way onto the 2025 KTM Motocross range, adding additional stiffness, bending resistance and braking feel to the overall package. At the other end, a forged steering head connection and CNC-milled triple clamps, make for the perfect alignment of the fork tubes. This precise geometry of the fork clamps ensures highly responsive and smooth fork action – not to mention unwavering stability when charging across ruts and onto the podium.



Getting power hooked into the dirt is a tough job. However, hours of research and testing have led the 2025 KTM Motocross range to the Dunlop GEOMAX MX34. Providing unmatched stability and control at the highest level, these rubber hoops feature a new carcass and rubber compound that improves damping and absorption, maintaining performance up to 30% longer. New Progressive Cornering Block Technology also improves grip in the berms, while a new rear pattern with 11% taller and 44% wider center block for increased traction and control everywhere else. Lastly, this unique block arrangement works to dispel mud buildup, ensuring traction in even the muddiest of track conditions.



Energy absorption

Besides the expertly crafted, hydro-formed, laser-cut, and robot-welded frame being engineered to provide exceptional rider feedback and straight-line stability, it consists of specifically calculated parameters of longitudinal and torsional flex. This means the frame acts as a “shock absorber” of sorts, making for a less harsh ride, resulting in less rider fatigue over many hard laps.


Ground clearance

No one enjoys a bad hook-up. Good thing, then that the shock absorber geometry on the 2025 KTM 300 SX improves ground clearance of the linkage, with the topology-optimized die-cast footpegs being less susceptible to hooking on deep ruts, and take-offs when scrubbing.




A new chain guide and chain guard result in improved durability and minimize the chances of hooking on external objects – especially in extremely muddy conditions while reducing dirt build-up around the swingarm and rear sprocket.




2025 KTM 300 SX – Totalmotorcycle.com International Specifications/Technical Details
Canada MSRP Price: $ TBA CDN
Europe/UK MSRP Price: £ TBA GBP (On The Road inc 20% Vat)

Transmission 5-speed
Starter Electric starter
Stroke 72mm
Bore 72mm
Clutch Wet, DDS multi-disc clutch, Brembo hydraulics
Displacement 293.2cm³
EMS Vitesco Technologies EMS
Design 1-cylinder, 2-stroke engine


Weight (without fuel) 99.4kg
Tank capacity (approx.) 7.2l
Front brake disc diameter 260mm
Rear brake disc diameter 220mm
Front brake Disc brake
Rear brake Disc brake
Chain 520, Non-sealed
Frame design Central double-cradle-type 25CrMo4 steel
Front suspension WP XACT-USD (AER), Ø 48 mm
Ground clearance 354mm
Rear suspension WP XACT Monoshock with linkage
Seat height 958 mm
Steering head angle 63.9°
Suspension travel (front) 310mm
Suspension travel (rear) 300mm



Manufacturer Specifications and appearance are subject to change without prior notice on Total Motorcycle (TMW).

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