SS 125

1977 Harley-Davidson SS 125 Technical Analysis & Specification Breakdown

Built around Harley-Davidson's minibike, sport motorcycle platform, the 1977 Harley-Davidson SS 125 utilizes a 123 cc (7.5 cu in) air-cooled single cylinder, two-stroke layout. In factory specification, peak output is rated at 13 HP (9.5 kW) at 7,000 rpm, transferring power to the rear wheel through a 5-speed gearbox and chain final drive. With a specific output of 105.7 HP per liter, the engine character is reflecting a performance-oriented street tune that balances strong mid-range pull with an energetic top-end rush.

On the scales, the SS 125 measures 112 kg (247 lbs) wet (curb), translating to a power-to-weight ratio of 0.12 HP/kg (8.62 kg per horsepower). The 10.5-liter (2.8 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 110 km/h (68 mph).

Within MotoLibrary's Harley-Davidson archive, this model family spans 2 indexed model years from 1976 to 1977, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.