Harley-Davidson S-125 Specs (Top Speed | Horsepower | Weight)

The Harley-Davidson S-125 motorcycle specifications include a 125 cc (7.63 cu in) engine, power of 3 hp (2.2 kW), a 3-speed gearbox, and a listed weight of 90.7 kg (200 lb).

Key specifications

1948-1959Model years
125 ccDisplacement
3 hpPower
90.7 kgDry weight
6.6 LFuel tank
Model years covered
194819491950195119521953195419551956195719581959
Year-specific specification changes

The 1948 model is treated as the standard specification. Only later model years with a different supplied value are shown below.

Displacement
19491954165 cc (10.07 cu in)
Front brakes
19491959Expanding brake (drum brake)
Fuel system
19491959Carburettor
Rear brakes
19491959Expanding brake (drum brake)

How the Harley-Davidson S-125 compares

This compares the motorcycle with all Harley-Davidson models in this specifications database. The blue marker is this model and the grey line is the Harley-Davidson database average.

Engine power3 hp
Low 19.3 hpAverage 63.9 hpHigh 119.7 hp

About 95% lower than the Harley-Davidson database average. Around the 1st percentile across Harley-Davidson models.

Displacement125 cc
Low 165 ccAverage 1,275 ccHigh 1,868 cc

About 90% lower than the Harley-Davidson database average. Around the 1st percentile across Harley-Davidson models.

Fuel capacity6.6 L
Low 7.9 LAverage 17 LHigh 22.7 L

About 61% smaller than the Harley-Davidson database average. Around the 1st percentile across Harley-Davidson models.

This model Harley-Davidson database average

Harley-Davidson database percentile rankings

Percentiles show where this motorcycle sits across the Harley-Davidson specifications database. They are descriptive database rankings, not performance ratings.

Engine power1st

3 hp — more powerful than about 1% of Harley-Davidson models with power data.

Displacement1st

125 cc — larger displacement than about 1% of Harley-Davidson models.

Fuel capacity1st

6.6 L — larger than about 1% of Harley-Davidson fuel tanks in this database.

Mechanical overview

Engine layout snapshot

Single cylinder, two-stroke • 125 cc • Air cooled • 3 hp
Chassis snapshot

3-speed • Chain (final drive) • 3.25-19 front / 3.25-19 rear

Additional useful specifications

Front tire size 3.25-19
Rear tire size 3.25-19
Power-to-weight ratio 0.033 hp/kg
Power-to-weight 33.1 hp/tonne
Specific power 24.0 hp/L
Bore/stroke ratio 0.90:1 (Undersquare)

Model information

Category Allround

Engine specifications

Engine type Single cylinder, two-stroke
Displacement 125 cc (7.63 cu in)
Power 3 hp (2.2 kW)
Bore × stroke 52.0 x 58 mm (2.0 x 2.3 inches)
Compression ratio 6.6:1
Cooling system Air
Fuel system Carburettor. Single Langsenkamp-Linkert
Starter Kick

Transmission and drivetrain

Gearbox 3-speed
Final drive Chain (final drive)

Chassis and suspension

Frame Single downtube steel cradle
Front suspension Girder fork coil spring
Rear suspension Rigid-

Brakes, wheels and tires

Front brakes Expanding brake (drum brake). SLS drum front and rear
Rear brakes Expanding brake (drum brake). SLS drum front and rear
Front tire 3.25-19
Rear tire 3.25-19

Dimensions and weight

Dry weight 90.7 kg (200 lb)

Fuel and emissions

Fuel capacity 6.62 L (1.75 US gal)

Performance

Top speed 72.4 km/h (45.0 mph)
Power/weight ratio 0.0331 hp/kg

Other specifications

Seat Spring-mounted seat
Comments Made in Germany in 1948 following Germany’s defeat in World War II.

Disclaimer: Specifications may vary by market, trim, production date and optional equipment, and scraped or historical data can contain errors. Comparison and percentile values are calculated from Harley-Davidson models in this specifications database. Always double-check important specifications against the motorcycle owner’s/service manual and official Harley-Davidson information before relying on them. Visit the official Harley-Davidson website.