KTM 125 SX - 2017 Specifications and Reviews

The 2017 KTM 125 SX is a lightweight, entry-level motocross bike ideal for junior riders and beginners stepping into competitive racing. Known for its nimble handling and responsive performance, it features quality WP suspension components and efficient braking systems that deliver predictable control on the track. Its compact dimensions and minimal weight make it the perfect platform for developing fundamental riding skills.

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General information

CategoryCross / motocross
Year2017
ModelKTM 125 SX
 
 

Engine and Transmission Specifications

Driveline13:50. Primary drive: 23:73.
ClutchMulti-plate clutch, Brembo hydraulics
Transmission type,final driveChain
Gearbox6-speed
Cooling systemLiquid
IgnitionKokusan EMS
Fuel systemCarburettor. Mikuni TMX
Bore x Stroke54.0 x 54.5 mm (2.1 x 2.1 inches)
Engine detailsReed intake.
Engine typeSingle cylinder, two-stroke
Capacity:124.80 ccm (7.62 cubic inches)

Brakes, suspension, Frame and wheels

WheelsCNC machined hubs. Excel rims. Wire spoked.
Rear brakes diameter220 mm (8.7 inches)
Rear brakesSingle disc. Brake calipers on floating bearings
Front brakes diameter260 mm (10.2 inches)
Front brakesSingle disc. Brake calipers on floating bearings
Rear wheel travel300 mm (11.8 inches)
Rear SuspensionWP shock absorber with linkage
Front wheel travel300 mm (11.8 inches)
Front SuspensionWP-USD, AER 48, Ø 48 mm
Rake (fork angle)26.5°
Frame typeChrome-molybdenum steel central-tube frame

Physical measures and capacities

Fuel capacity7.00 litres (1.85 gallons)
Wheelbase1,485 mm (58.5 inches)
Ground clearance375 mm (14.8 inches)
Seat height960 mm (37.8 inches) If adjustable, lowest setting.
Dry weight87.2 kg (192.2 pounds)

Other specs

MaintenanceFind parts, fluids, filters, maintenance tools and service items on eBay
StarterKick
Color optionsOrange/white/black

Performance Profile & Rider Fit

Best For

Track95%
City10%
Cornering90%
Daily Riding10%
Touring8%
Passenger5%

Rider Profile

Best ForThis is a full-on motocross competition bike best suited to intermediate through expert off-road riders, not beginners or casual road riders.
PurposeBuilt purely for closed-course motocross racing, it excels at jumps, berms, and rapid direction changes on dirt tracks rather than any street use.
Rider FitThe tall 958 mm seat height, aggressive ergonomics, and demanding 2-stroke power delivery require good rider fitness, strength, and prior dirt bike experience.
CharacterLight, explosive, and razor-sharp in handling, it rewards aggressive riding with a peaky two-stroke power band and minimal weight to manage.
Not Ideal ForIt is not suitable for commuting, highway travel, passengers, or riders seeking comfort, storage, or a forgiving low-end power delivery.

Character map is an editorial estimate based on this bike's specifications, not a lab-tested measurement.

Rider Fit Visualizer

2017 KTM 125 SX Rider Ergonomics Assessment

Calculated in your browser only - your height/inseam are never sent to our servers.

Feet:

At 960mm, a rider of 175cm with a 79cm (estimated) inseam will reach the ground with cannot reach comfortably on the 2017 KTM 125 SX, with a cramped knee angle of around 85 degrees and an upright riding position.

Data quality: measured. Assumes about 30mm of suspension sag once seated (a typical street-bike rule of thumb - stiffer or softer suspension will vary). This is an approximation from category-typical geometry and generic body proportions, not a measurement of this specific bike or you - sit on it before you buy.

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