Besides the expertly crafted, hydro-formed, laser-cut, and robot-welded frame being engineered to provide exceptional rider feedback and straight-line stability, the chassis 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.
Review – Key Features – Features & Benefits – Specifications
2026 KTM 125 SX: FULL-SCREAM AHEAD.
Introducing the 2026 KTM 125 SX…
There are very few sounds that can’t be beaten: the crack of a soda can on a blistering hot day, the ping of the perfectly executed golf shot, and the scream of a 125 cc 2-stroke full throttle. The KTM 125 SX takes its leads directly from the KTM Factory Racing team for pure performance, pure results. Like the sound it makes, you won’t forget it.
2026 KTM 125 SX Totalmotorcycle.com Key Features
THE 2026 KTM SX RANGE SETS THE LATEST MOTOCROSS STANDARD
A new season, new objectives and new standards. Those seeking utter performance and a comprehensive expression of power, handling, proven competitiveness and an unmissable image need to look no further than the refreshed KTM SX Motocross roster for 2026. Coming to an authorized KTM dealer near you from August 2025, the peerless KTM SX range will entice every rider, every age and every level to soak up the ultimate Motocross experience and the thrill of shredding terrain.
A total of 10 models lie in store. The KTM Sportminicycles:
KTM 50 SX
KTM 50 SX FACTORY EDITION
KTM 65 SX
KTM 85 SX
The full size 2-stroke and 4-stroke spectrum:
KTM 125 SX
KTM 250 SX
KTM 300 SX
KTM 250 SX-F
KTM 350 SX-F
KTM 450 SX-F
FULL-SIZE FIREPOWER: KTM SX & SX-F MODELS LEAD THE PACK
The 2026 lineup remains on top of the podium thanks to KTM’s SX philosophy of agile handling and race-winning power. Every model is equipped with class-leading electronics, refined chassis dynamics and explosive power delivery. Riders aiming for factory-level precision can unlock full adjustability with the optional Connectivity Unit Offroad (CUO). Paired with the KTMconnect app, it enables fine-tuning of engine behavior, traction control, and suspension settings.
The settings and configuration of the full size KTM SXs and KTM SX-Fs come from the substantial success and learnings of competition in the FIM Motocross World Championship (wins in both MXGP and MX2 classes with the KTM 450 SX-F and KTM 250 SX-F) and the AMA Supercross and Motocross series. Depending on the market there are also options with a default noise decibel limit to adhere to FIM guidelines from the start of the 2025 calendar year. The latest model lineup is easy to detect on all models with a revitalized orange aesthetic, the principal color and graphics now also embracing a shade of purple on the tank spoilers and fork guards. The frame is powder-coated black with a matching black seat.
KTM has tweaked the radiator closure to be more standardized and for easier access on all KTM SXs. Where applicable, all fuel injection units have a new protector cap for the fuel link quick lock system that will beef-up durability and also assist with maintenance. The 2-stroke KTM SXs have an improved wiring harness routing and the adjustments of the fixing points and organization represent another effort for resistance against the elements.
THE NEXT GENERATION OF RACERS STARTS HERE
KTM’s commitment to providing the widest and highest quality platform of progression for young riders is steadfast for 2026. KTM Sportminicycles remain a cornerstone of development, giving young riders the tools to start their journey – from first laps on the electric KTM SX-E models to racing progression with the KTM 50 SX and KTM 85 SX.
Fun or first place? The 2026 KTM Sportminicycles will carry youth on their way. The KTM 50 SX and KTM 65 SX benefit from a new WP XACT AER front fork with a renewed air cartridge and sealing concept for better damping, control and overall performance. The radiator closure has been tweaked to be more standardized and for easier access same as on the bigger KTM SX models. The triple clamps for the KTM 50 SX, KTM 65 SX and KTM 85 SX now have the same 17 mm wrench size and closed screw nut format as the full size KTM SXs to add a further barrier against dirt and water intrusion. On the theme of resistance, the throttle cable assembly is less prone to kinking and deformation thanks to a new stabilization cap.
The 2026 KTM 65 SX takes the next for maximum durability with an overhauled clutch fixation system in place. The pre-coating and increased torque tightening mean a step up in terms of excellence. Running through these KTM SXs, a new laser-cut exhaust flange gasket promotes more reliability and the exhaust valve ventilation emanating from the cylinder has been redesigned in Austria with the same mission in mind. The KTM 85 SX has been given a new rear brake lever with two adjustment options for length to the brake tip. This will help in terms of set-up for different sized kids who are making the transition from the KTM 65 SX to the bigger 85 SX.
The KTM 50 SX FACTORY EDITION is for any child that is already fantasizing of checkered flags and does not tire of watching their racing heroes. The READY TO RACE KTM PowerParts components and factory team replica livery will pull them closer to the dream and create a tight link to Red Bull KTM Factory Racing stars.
2026 KTM SX RANGE HIGHLIGHTS:
- Latest iterations of technical base that has won championships and races in both international and domestic competition across the globe.
- Latest 2026 in-mold graphics and color scheme with greater orange emphasis, purple details, black seat and black frame color.
- KTM Sportminicycle are packed with new upgrades, including improved WP XACT suspension, updated clutch components, and refined durability across the board.
- Full collection of KTM PowerParts and KTM PowerWear to complement each motorcycle from protection to customization, performance and aesthetics.
Manfred Edlinger, Head of Motocross Development:
“We’re in the fourth year of the current generation for the KTM SX full-size models, the third for the KTM 50 SX and 65 SX and the second for the KTM 85 SX: the bikes keep moving from strength to strength as we find measures and changes to make sure we stay at the forefront of choice for all racers. The whole full-size range has been re-styled, but we’ve also found ways to bolster the KTM Sportminicycles because we know the components, the performance and the technical base of these special KTM bikes will satisfy the hungriest little racer or their supportive family. Embrace the ‘bar’ again, because we’re pumped to continue lifting it in motocross.”
2026 KTM 125 SX Totalmotorcycle.com Features and Benefits
CLICK INTO ACTION
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 option allows riders to adjust high- and low-speed settings in a matter of seconds. The forks on the front end are also easily modified thanks to hand-adjustable clickers on the bottom of the fork shoe and top cap.
NO JETS – ONLY ROCKET SHIPS
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 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. For 2026 there is a new fuel protector cap: you’ll still have quick and easy access for maintenance but now more safety against any outside damage and accidental opening as well as preventing dirt from entering the sides of the connector.
CHUGGA CHUGGA, RING DING DING!
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 don’t sweat it. All you do is press the starter button and you blast off again to take the flag. This is the reality on the KTM SX models. Thanks to a 12.8V 2 Ah lithium ion battery placed under the rider’s seat, a high-quality starter and pickup, and super robust design, the only thing you’ll be kicking – is ass.
LESS FOCUS ON THE TOOL, MORE FOCUS ON THE TRACK
Serviceability
The KTM SX and SX-F range is engineered and designed to provide riders with easy-to-access service parts, as well as suspension adjustability. This permits faster trackside and off-season maintenance, as well as simplifying motocross for novice riders without pit crews.
MORE BRAAAP!
Factory Performance Kit
Give your KTM 125 SX a more bite with a 125 Factory Performance Kit.
SMOOTHER POWER DELIVERY
EFI + Power Valve
With EFI comes great rideability. Along with the electronic fuel injection is an electronic power valve on the KTM 125 SX, allowing for more usable power throughout the rev range. Smoother power means better traction. Better traction means holeshot heaven!
UNMATCHED PERFORMANCE
Performance
Designed to churn out torque, the KTM 125 SX is set to continue its dominance in its class with unrelenting forward momentum. The overall engine weight is only 39.7 lb (17.86 kg) and carries impressive horsepower figures. This lightweight powerplant retains its typical high-revving character while laying down the grunt where it matters most.
PICK YOUR POWER
Selectable Maps
Once again slicing into the 125 cc class with the leading edge of technology, the KTM 125 SX features a map select switch allowing the racer to switch between 2 engine maps. The White Map – or Map 1 – provides a linear, predictable power delivery ideally suited to attack hard-packed dirt with a leaner air-fuel mixture. Alternatively, the Green Map – Mapping 2 – is tuned for loose, thick sandy conditions with a richer mix.
SLEEKER FOR YOU TO SCRUB CLEANER
Absolute Control
Get ready for a full-on berm assault. The KTM SX and SX-F machines received major frame updates directly from KTM Factory Racing efforts. For starters, the area around the rear shock mount is streamlined, with engine mounts and cut-outs for improved chassis flex. The front area of the frame has an optimum wall thickness with renewed engine mounts.
FLUID RIDER MOTION
Ergonomics
Tank shrouds using bi-compound plastics channel air towards the radiators more efficiently, while a concise 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.
STURDY FRONT END
WP XACT Fork
Let’s get the technical parts out of the way first; the 48 mm WP XACT AER forks fitted to the 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 has settings which not only compliment the 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 WP air pump needed to adjust the fork’s air pressure is provided as standard in the buy-pack.
TRACK SMOOTHER
WP XACT SHOCK
Keeping things in check at the rear, the WP XACT rear shock uses settings directly from the KTM Factory Racing Teams. The frame and shock geometry mean more ground clearance at the linkage, making it less susceptible to bottoming out. Small diameter linkage bolts save weight, while optimal linkage seals refine rear shock response and advanced damping characteristics.
RACING ON RAILS
Stability
The KTM Motocross range has a special rear brake pedal 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.
Tires
Getting power hooked into the dirt is a tough job. However, hours of research and testing have led the KTM Motocross range to the Dunlop GEOMAX MX34. Providing unmatched stability and control at the highest level, the rubber features a rigid carcass and compound that improves damping and absorption, maintaining performance up to 30% longer than previous models. Progressive Cornering Block Technology also improves grip in the berms, while the rear pattern has a tall and wide center block for desirable traction and control everywhere else. Lastly, this unique block arrangement works to dispel mud buildup, ensuring traction in even the muddiest of track conditions.
PRECISE, LAP AFTER LAP
Consistency
Count on a durable chain guide and chain guard and minimize the chances of hooking on external objects – especially in extremely muddy terrain while reducing dirt build-up around the swingarm and rear sprocket. For 2026 we’ve also modified the fixing points and routing of the wiring harness so it’s less prone to wear and damage.
UNOBTRUSIVE IMPACT
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, the chassis 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.
NOTHING TO HOLD YOU BACK
Ground clearance
The shock absorber geometry on the KTM SX and SX-F machines gives decent ground clearance for the linkage, with the topology-optimized die-cast footpegs being less susceptible to hooking on deep ruts, and take-offs when scrubbing.
2026 KTM 125 SX – Totalmotorcycle.com International Specifications/Technical Details
US MSRP Price: $ See Dealer USD
Canada MSRP Price: $ See Dealer CDN
Europe/UK MSRP Price: £ See Dealer GBP (On The Road inc 20% Vat)
Engine
Design
1-cylinder, 2-stroke engine
Displacement
124.8 cm³
Transmission
6-speed
Fuel-mixture generation
Keihin EFI, throttle body 39 mm
EMS
Vitesco Technologies EMS
Clutch primary drive teeth
73
Primary drive
23:73
Clutch
Wet multi-disc DS clutch, Brembo hydraulics
Clutch type
DS multi-disc wet clutch
Clutch operation
Brembo hydraulics
Engine cylinder
Single cylinder
Engine stroke
2-Stroke
Chassis
Frame design
Central double-cradle-type 25CrMo4 steel
Front brake
Disc brake
Rear brake
Disc brake
Rear subframe design
Aluminum-reinforced polyamide
Chain
520, Non-sealed
Suspension
Front suspension
WP XACT-USD (AER), Ø 48 mm
Rear suspension
WP XACT Monoshock with linkage
Suspension travel (front)
310 mm
Suspension travel (rear)
300 mm
Front suspension adjustment
Compression (high and low speed), rebound
Rear suspension setting
Compression and rebound adjustable
Dimensions
Seat height
958 mm
Ground clearance
359 mm
Tank capacity (approx.)
7.2 l
Manufacturer Specifications and appearance are subject to change without prior notice on Total Motorcycle (TMW).
Posted on July 30, 2025 by Michael Le Pard
