Motocross · 2-stroke · 125

KTM 125 SX

2027 · 92 kilos, wide open.

The 125 class is where riders learn to carry speed, and this is the bike that won the 2026 125 World and European titles doing it. Available through NTG for teams and resellers, EU-wide.

€ 7 670net · excl. VAT · per unit

See how to order Technical details

01.Before the gate

Setup, injection and a starter button — the two-stroke that asks nothing of you before the gate drops.

4 features

Click into action

Easy suspension adjustment

Tool-free at both ends. The shock has hand-adjustable high- and low-speed compression, so a change takes seconds, not a session. Fork clickers sit on the shoe and the top cap, also by hand. You chase the setting between motos, not between weekends.

No jets, only rocket ships

Electronic fuel injection

No jets, no pre-race fiddling. Keihin EFI with a reed-valve case meters the mixture for altitude and temperature on its own, so the bike makes the same power at sea level and in the mountains. The fuel-connector protector cap keeps dirt and knocks away from the one part you don't want to fail.

Press and go

Electric start

Stall in a rut on lap seven, press a button, go. A 12.8 V / 2 Ah lithium-ion battery under the seat, a quality starter and pickup — kickstarting a race two-stroke is history.

Less tool, more track

Serviceability

Service parts are placed where you can reach them and suspension is adjustable without a toolbox. Faster trackside and off-season maintenance for teams — and a bike a privateer can run without a crew.

02.Start strong

A 17.9 kg engine that revs like a 125 should and pulls where a 125 usually doesn't.

4 features

Unmatched performance

Performance

Built for torque as much as revs: the 124.8 cm³ engine weighs 17.86 kg, keeps the classic high-revving 125 character, and lays the power down where it matters — out of the corner, not just at the end of the straight. The 2026 125 World and European Championships were won on it.

124.8cm³
17.9 kgengine
92 kgwithout fuel

Pick your power

Selectable maps

Two engine maps on a bar-mounted switch. Map 1 is linear and predictable for slick or muddy tracks; Map 2 is crisp and explosive when the dirt is good. Change it on the line, not in the pits.

Smoother delivery

EFI + electronic power valve

EFI and an electronically controlled power valve give the 125 usable power across the whole rev range instead of one narrow hit. Smoother delivery means more traction — and on a 125, traction is lap time.

More braaap

Factory Performance Kit

Available as a PowerParts option: upgraded engine parts, a Factory expansion chamber and dedicated mapping — about 2.5 hp more and 15 % less weight than the standard exhaust parts. Ask us to spec it with the bike.

03.Calm under fire

The same factory-developed frame as the big bikes — flex where you want it, none where you don't.

2 features

Sleeker to scrub cleaner

Absolute control

Revised frame with KTM Factory Racing input: a streamlined shock-mount area, optimised engine mounts and cut-outs for controlled chassis flex, tuned wall thickness at the front. Built for a full-on berm assault.

Fluid rider motion

Ergonomics

Bi-compound tank shrouds feed the radiators and give real knee grip when you're standing. A tighter fuel-tank roll means less frame scrubbing — bodywork that lasts a season, not a month — and a rider triangle that keeps you locked in on the pegs.

04.Hit the big stuff

Full-size WP XACT suspension, full-size rubber. Nothing on the 125 is a junior part.

4 features

Sturdy front end

WP XACT fork

48 mm WP XACT AER: capsulated air spring and pressurised oil chamber for progressive, consistent damping; bypasses trim the pressure peaks; mid-valve damping gives feedback you can read. One air valve for preload, hand clickers for compression and rebound. The WP pump ships in the box.

Ø 48 mm
310 mmtravel

Track smoother

WP XACT shock

Settings lifted from the factory teams. Frame and shock geometry give more ground clearance at the linkage, so it stops bottoming; smaller linkage bolts save weight; refined seals give a cleaner stroke.

300 mmtravel

Racing on rails

Stability

A forged steering-head connection and CNC-milled triple clamps keep the fork tubes perfectly aligned — responsive, smooth fork action and an honest front end across ruts. A stiffened rear brake pedal adds bending resistance and better brake feel.

Digging the dirt

Tires

Dunlop GEOMAX MX34. Rigid carcass and a compound that holds performance up to 30 % longer; Progressive Cornering Block Technology for berm grip; a tall, wide centre block at the rear for drive — and a pattern that clears mud instead of packing it.

05.Maintaining momentum

Nothing to hook, nothing to snag, and a frame that soaks up the hits so you don't have to.

3 features

Nothing to hold you back

Ground clearance

Shock geometry keeps the linkage high, and topology-optimised die-cast footpegs are far less likely to hook a deep rut or a take-off when you're scrubbing.

359 mmground clearance
958 mmseat height

Precise, lap after lap

Consistency

A durable chain guide and guard resist hooking in deep mud and keep dirt from building up around the swingarm and sprocket. For 2027 the wiring harness has new fixing points and routing, so it stops being the part that wears first.

Unobtrusive impact

Energy absorption

Hydro-formed, laser-cut, robot-welded 25CrMo4 steel with calculated longitudinal and torsional flex. The frame works as a shock absorber of its own — a less harsh ride, straight-line stability, and less fatigue over thirty hard laps.

06.Warranty & support

New bikes, delivered through authorised channels, with the paperwork the warranty is tied to.

Model year 2027 onwards

Premium manufacturer's warranty

Offroad bikes from model year 2027 carry up to 1 year of manufacturer coverage. It stays valid with intended use and scheduled services at an authorised KTM dealer, under the standard conditions on the delivery certificate. Every bike NTG supplies is new and comes with that certificate.

Technical details

Specifications

Manufacturer data, model year 2027. Delivered spec can vary by market — we confirm on the order confirmation.

Design1-cylinder, 2-stroke

Displacement124.8 cm³

Transmission6-speed

Fuel systemKeihin EFI, 39 mm throttle body

Engine managementVitesco Technologies EMS, 2 maps

ClutchWet DS multi-disc, Brembo hydraulics

Primary drive23:73

Engine weight17.86 kg

FrameCentral double-cradle, 25CrMo4 steel

SubframeAluminium-reinforced polyamide

Front brakeDisc, Brembo

Rear brakeDisc, Brembo

Chain520, non-sealed

TiresDunlop GEOMAX MX34

FrontWP XACT-USD (AER), Ø 48 mm

RearWP XACT monoshock with linkage

Travel front310 mm

Travel rear300 mm

Front adjustmentAir preload, compression, rebound

Rear adjustmentHigh/low-speed compression, rebound

Seat height958 mm

Ground clearance359 mm

Tank capacity7.2 l

Weight, without fuel92 kg

Order

2027 KTM 125 SX

New, uncrated, delivered through authorised channels. Priced net, excl. VAT, for teams and resellers. Tell us the quantity and destination and we quote within one working day.

AvailabilityOn request
Price€ 7 670 net · excl. VAT
DeliveryEU-wide

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Product images and technical data © KTM AG, used for product identification. North Trade Group is an independent trader and not an authorised KTM dealer or distributor. Specifications subject to change by the manufacturer.