When you’ve graduated from the introductory dirt bikes in KTM’s line-up, the next step is riding a junior bike that has championship tradition. Kind of like the KTM 125 SX.

Those wanting to race in the Junior World Championship need look no further than this beauty to stay competitive. The free-revving and lively two-stroke engine has gained even more performance for the current season. If you thought that the 125 SX’s 125cc 1-cylinder 2-stroke engine was impressive, its newly developed exhaust expansion chamber has not only improved in quality, but it now comes with an optimized soundbox that ensures an extra shot of engine power that’s explosive and dependable, all at the same time.

The 125 SX also comes with a completely revamped frame made from high-quality chrome-molybdenum steel that’s extremely light and torsion-resistant. The bike 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 also now equipped with an elaborate linkage rear suspension system.

Linking the shock absorber via a lever system provides high progressiveness and wide adjustment ranges. Apart from the new linkage rear suspension, there is the new cast aluminum swingarm, which is designed for minimum weight while supplying optimum lateral stiffness and defined longitudinal flexibility. This makes a major contribution to the 125 SX’s excellent tracking stability, playful handling, and extreme traction, making for a bike that’s got plenty of substance to back up its long-standing tradition as a motocross bike that has a history of championship-winning performances.

Find out more about the KTM 125 SX after the jump.

  • 2012 KTM 125 SX
  • Year:
    2012
  • Make:
  • Model:
  • Engine:
    Single cylinder, 2-stroke
  • Transmission:
    6 gear, claw shifted
  • Energy:
    Keihin PWK 38S AG
  • Displacement:
    124.8cc L
  • Price:
    $6,299

Engine

2012 KTM 125 SX Drivetrain
- image 434988

The 125 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

2012 KTM 125 SX High Resolution Exterior
- image 434989

The 125 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.

New Frame and Suspension

2012 KTM 125 SX High Resolution Exterior
- image 434992

The 125 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 125 SX therefore has a season ticket for the podium, even on the most brutal motocross courses.

Apart from the new linkage rear suspension, there is the new cast aluminum swingarm, which is designed for minimum weight while supplying optimum lateral stiffness and defined longitudinal flexibility. This makes a major contribution to the 125 SX’s excellent tracking stability, playful handling and extreme traction.

Bodywork

2012 KTM 125 SX High Resolution Exterior
- image 434985

The 125 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 Exhaust Expansion Chamber

2012 KTM 125 SX High Resolution Exterior
- image 434986

The 125 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.

New Telescopic Fork Setting

2012 KTM 125 SX High Resolution Exterior
- image 434991

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 125 SX.

Specifications

2012 KTM 125 SX High Resolution Exterior
- image 434993
Design 1-cylinder 2-stroke engine, water-cooled, with reed intake and exhaust control
Displacement 124.8 cm³ (7.616 cu in)
Bore 54 mm (2.13 in)
Stroke 54.5 mm (2.146 in)
Starting aid Kickstarter
Transmission 6 gear, claw shifted
Primary gear 23:73
Final drive 13:50
Clutch Wet multi-disc clutch / hydraulically operated
Ignition system Contactless, controlled, fully electronic ignition system with digital ignition timing adjustment, type Kokusan
Frame Central tube frame made of chrome molybdenum steel tubing
Forks WP Suspension Up Side Down 4860 MXMA CC
Shock absorber WP Suspension 5018 BAVP DCC
Suspension travel Front 300 mm (11.81 in)
Suspension travel Rear 330 mm (12.99 in)
Brake system 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)
Chain 5/8 x 1/4"
Steering head angle 63.5°
Wheel base 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.)

Quotes

Motorcycle-USA----"Precise handling and extreme traction is being supplied by the optimum lateral stiffness and defined longitudinal flexibility from minimum weight due to the new linkage on the rear suspension. The KTM 125 SX has extremely well handling and traction."

What do you think?
Show Comments

1 comments:

  (594) posted on 02.8.2012

The bike has a functional design making the it easier to handle and more precise. The frame of the motorcycle is made extremely light chrome-molybdenum steel. This is perfect for a motor cross.

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