Anybody that has ever ridden a motocross bike understands the thrill of it all. Those that have taken it a step further and competed in motocross understand that there’s nothing like it.
That’s why, if you’re part of the latter and you want to race in the Junior World Championship, you need not look further than the KTM 125 SX. Designed with slim bodywork emphasized by a slim seat and spoiler lines, the 125 SX is the kind of bike that young riders can go to battle with.
What’s better, the free-revving and lively 125cc two-stroke engine has gained even more performance for the current season, something that seems highly improbable given the impressive credentials of its predecessor.
But the thing that makes the 150 SX such a special motocross bike is that KTM has built a completely new frame and a new, progressive linkage rear suspension. Apart from the new linkage rear suspension, there is the new cast aluminum swingarm, which has been designed for minimum weight and supplies optimum lateral stiffness and defined longitudinal flexibility. This is a major contribution to the 150 SX’s excellent tracking stability, playful handling, and extreme traction.
The further improved upside-down telescopic fork incorporating closed-cartridge technology now ensures even greater punch with a somewhat tauter setting. At the same time, the WP fork with 48 mm (1.89 in) outer tube diameter bolsters the playful handling of the 150 SX to levels that are championship worthy.
If somebody asked you what junior motocross bike you’d like to have on your side in the strongest of competitions, you won’t find anything better than the 150 SX.
Find out more about the KTM 150 SX after the jump.
The 150 SX’s flow-optimized intake flange between airbox and carburetor now ensures even better charging with fresh gas. This results in even freer revving and even more power in all rev ranges for the liquid-cooled, two-stroke machine.
New Exhaust Expansion Chamber
The 150 SX’s new exhaust expansion chamber has not only improved in quality; in conjunction with the two-stroke machine’s exhaust control system, its optimized soundbox ensures an extra shot of engine power - explosive, but dependable.
The 150 SX’s bodywork with the very slim seat and spoiler lines, plus excellent contact points, perfects the bike’s ergonomics, making handling even simpler and more precise.
New Frame and Suspension
The 150 SX’s completely revamped frame made from high-quality chrome-molybdenum steel is not only extremely light and torsion-resistant. It is also characterized by a particularly balanced geometry that combines playful handling with razor-sharp precision.
The two-strokes in the MX range from KTM are now also equipped with the elaborate linkage rear suspension system. Linking the shock absorber via a lever system provides high progressiveness and wide adjustment ranges. The 150 SX therefore feels at home, even on the most brutal motocross courses.
1-cylinder 2-stroke engine, water-cooled, with reed intake and exhaust control
143.6 cm³ (8.763 cu in)
56 mm (2.2 in)
58.4 mm (2.299 in)
6 gear, claw shifted
Wet multi-disc clutch / hydraulically operated
Contactless, controlled, fully electronic ignition system with digital ignition timing adjustment, type Kokusan
Central tube frame made of chrome molybdenum steel tubing
WP Suspension Up Side Down 4860 MXMA CC
WP Suspension 5018 BAVP DCC
Suspension travel Front
300 mm (11.81 in)
Suspension travel Rear
330 mm (12.99 in)
Disc brakes, brake calipers on floating bearings
Brake discs - diameter Front
260 mm (10.24 in)
Brake discs - diameter Rear
220 mm (8.66 in)
5/8 x 1/4"
Steering head angle
1,480±10 mm (58.27±0.39 in)
Ground clearance (unloaded)
395 mm (15.55 in)
Seat height (unloaded)
992 mm (39.06 in)
Total fuel tank capacity approx.
7.5 l (1.98 US gal)
Unleaded premium fuel, mixed with 2-stroke engine oil (1:40)
Weight without fuel approx.
91.6 kg (201.9 lb.)
Motorcycle-USA----"The engine power of the KTM 150 SX is closer to that of the 250 that the 125 and has better performance than it did before. It has top ergonomics with a perfect contact points for nicer handling. This is a hardy machine that is very well equipped with just about everything you need."