The 2025 KTM 50 SX is fitted with a centrifugal clutch reducing the complexity for younger riders, and helping to boost riding confidence. The multi-disc clutch delivers a precise and predictable power delivery across the RPM range.
Review – Key Features – Features & Benefits – Specifications
2025 KTM 50 SX: WINNING STARTS HERE!
Introducing the 2025 KTM 50 SX…
When the next step up is into the 50cc class, there is no better option than the most powerful 50cc out there. For 2025, the KTM 50 SX is built around an advanced steel frame, housing a powerful engine, a 35mm WP XACT AER fork, a WP XACT monoshock, and an advanced hydraulic Formula brake system. Simply put – it’s the most advanced and READY TO RACE 50 cc mini-crosser available to your little racer.
2025 KTM 50 SX Totalmotorcycle.com Key Features
UNMATCHED 2-STROKE PERFORMANCE
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.
2025 KTM 150 SX BACK ON THE ATTACK
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.
NEXT LEVEL MOTO
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.
EVER-EVOLVING PERFORMANCE
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.
KTM TAKES RIDER CONNECTION TO THE NEXT LEVEL WITH THE 2025 KTM MOTOCROSS RANGE
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 50 SX Totalmotorcycle.com Features and Benefits
Before The Gate
Adjustablity
Different adjustability options were built into the 2025 KTM 50 SX construction using scientific statistical data and young racers’ input data. Finding the right fit for your little ripper is easy thanks to height-adjustable suspension, handlebar position, subframe, and bodywork, taking the seat height from a low setting of 634mm to a taller setting of 682mm.
Ignition
Fitted with a digital ignition the with improved processing power making for a cleaner burn and smoother power delivery. Individual ignition timing across the entire rpm range, just like that found on the full-sized KTM SX range, adds a key advantage.
Carburetor
A proven Dell’Orto type PHBG 19 BS carburetor takes a prime position in producing the goods in the 2025 KTM 50 SX, that works perfectly in harmony with the engine, exhaust, and air intake design.
Start Strong
Performance
The 2025 KTM 50 SX features a modern and compact engine using the latest 2-stroke technology. Using a 3-shaft design, the crankshaft is positioned near the center of gravity, which not only benefits mass centralization but also creates the ideal intake angle into the reed valve for top-level performance. An independent cylinder blank allows for a completed cylinder design, with increased power.
Power-Reduction Kits
For absolute beginners, the KTM POWERPARTS catalog offers a choice of two power-reduction kits. The first allows for a entry-level, moderate and controllable power reduction to 4hp, with the second allowing for a more intermediate power kit unleashing 8hp for mid-level riding levels.
Clutch
The 2025 KTM 50 SX is fitted with a centrifugal clutch reducing the complexity for younger riders, and helping to boost riding confidence. The multi-disc clutch delivers a precise and predictable power delivery across the RPM range. It can be set to suit rider preferences or track conditions without using any special tools. Also, a reinforced clutch basket provides Improved durability, wear, and consistent performance.
Spark Plug
There’s no more worrying about breaking the plug, thanks to the 2025 KTM 50 SX featuring a spark plug from BRISK with a longer thread. Also, thanks to this innovation from BRISK, the part number is printed on the spark plugs for easy reading.
Calm Under Fire
Tank
The KTM 50 SX is ready to fuel the fire in your little ripper with a tank design that compliments the frame and bodywork.
Airbox and Filter
The airbox features a conventional suction sleeve made from a hard-wearing polyamide instead of rubber and a Twin Air filter mounting system that features snap locks for easy and intuitive mounting. The Twin Air filter is also placed under the seat and is easily accessible without any tools by simply removing the seat. It also features improved dirt intrusion resistance, with no more dirt falling into the intake tract when changing the filter.
Ergonomics
Mimicking the full-size KTM SX range, the KTM 50 SX features the same advancements found in the larger KTM SX range. Slimmer, sleeker, and better suited to standing on the pegs, the side panels now work much better with young riders’ boots, allowing a proper squeezing of the bike when standing up. The front number plate incorporates plastic flaps to protect the lower triple clamps from roost, while the tank spoiler features a bicomponent technology featuring the KTM-specific texture on the upper part. Side number plates are kept as close to the frame as possible, with the general seat line sitting slightly flatter.
Handlebars & Grips
Hold on tight! The high-quality, tapered, black handlebar is made of lightweight aluminum alloy and ensures top stability, vibration damping, and control. The bend and profile is designed specifically to meet the needs of young riders, with ODI grips on the left, and a vulcanized ODI grip on the right-side throttle assembly, adding to the overall quality. A crash pad on the handlebar protects the rider from any rough contact or impact with the bars.
Frame
Right, this is a big one. The 2025 KTM 50 SX boasts a high-strength chromium molybdenum steel frame design with forged connecting parts integrated into the frame. This together with carefully calculated parameters of longitudinal flex and torsional rigidity, allow tailormade stiffness and an unprecedented quality of the Mini frame could be achieved. The frame layout features a typical MX design without any cross tube behind the steering head. Like our full-size models, the rear shock mount is separated from the main upper frame tube. The frame also comes with frame protectors as standard.
Hit The Big Stuff
Wheels & Tires
Rolling off the race rig and into the pit lane, the 2025 KTM 50 SX uses lightweight, black anodized, aluminum rims just like the full-size KTM SX range. These provide the highest levels of strength and reliability, while MAXXIS MX-ST tires deliver outstanding performance on any terrain, along with exceptional straight-line stability.
Footpegs
A “no-dirt” footrests offer a bigger surface area for improved grip while standing on the pegs, and are less susceptible to hooking up in deep ruts, take-offs when scrubbing, or track barriers.
Suspension
Featuring the latest in suspension technology, the KTM 50 SX is fitted with a state-of-the-art, lightweight 35mm USD WP XACT AER fork. With 205mm of wheel travel, the air unit in the left fork leg can also be adjusted easily using an air pump for rider preference, rider weight, or track conditions. At the rear, a fully-adjustable WP XACT monoshock boasts mounting points on the frame, making it more compact, and providing the perfect balance and damping characteristics to match the fork.
Brakes
Featuring the same level of technology offered on the full-size KTM SX range, the 2025 KTM 50 SX is fitted with hydraulic brake calipers and state-of-the-art front and rear waved brake discs. This system ensures advanced braking feel and unmatched stopping performance in all conditions, specifically on wet or muddy tracks, with improved durability and brake pad longevity.
Maintaining Momentum
Exhaust
The exhaust system, features the same manufacturing process as the full-size 2-stroke KTM SX range, with improved overall quality and performance. This has resulted in massive improvements in thermodynamics. Moreover, improved sealing of the silencer end cap and a rubber between the header pipe and silencer adds another level of quality to the exhaust system. The silencer comes with a black anodized finish and a signature ‘Braaaaap!’.
Radiator
Featuring state-of-the-art technology and superior cooling power, the 2025 KTM 50 SX uses one large radiator with more capacity instead of two smaller separate ones. This concept allows for better integration of the radiator into the frame and the tank spoilers to channel air through the cooling fins efficiently.
Hour Meter
Keep track of engine hours easily, with an hour meter mounted at the same position behind the front number plate – as on the full-size KTM SX models. This makes for easier reading and has a lower risk of dirt and water fowling up the display.
Graphics
Modeled after the full-size motocross bikes, the KTM 50 SX features typical READY TO RACE graphics using the time-proven in-mold application process to ensure the best durability and quality.
2025 KTM 50 SX – Totalmotorcycle.com International Specifications/Technical Details
US MSRP Price: $ TBA USD
Canada MSRP Price: $ TBA CDN
Europe/UK MSRP Price: £ TBA GBP (On The Road inc 20% Vat)
Engine
Transmission Single-speed automatic
Starter Kickstarter
Stroke 40.7mm
Bore 39.5mm
Clutch Centrifugal clutch (adjustable)
Displacement 49.9cm³
EMS Seletra 2p D36
Design 1-cylinder, 2-stroke engine
Chassis
Weight (without fuel) 42.5kg
Tank capacity (approx.) 2.3l
Front brake disc diameter 160mm
Rear brake disc diameter 160mm
Front brake Disc brake
Rear brake Disc brake
Chain 415, Non-sealed
Frame design Chrome-molybdenum steel central-tube frame
Front suspension XACT 35 WP Upside-Down fork, Ø 35 mm
Ground clearance 233mm
Rear suspension XACT WP mono shock
Seat height 653 mm
Steering head angle 66°
Suspension travel (front) 200mm
Suspension travel (rear) 190mm
Manufacturer Specifications and appearance are subject to change without prior notice on Total Motorcycle (TMW).
