Sport · 1921

Sport Twin

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1923 1922 1921 1920 1919

Technical Overview

1921 Harley-Davidson Sport Twin Technical Analysis & Specification Breakdown

At the heart of the 1921 Harley-Davidson Sport Twin sport motorcycle, Harley-Davidson utilizes a 590 cc (36 cu in) air-cooled twin, four-stroke layout. Internal engine geometry specifies a bore and stroke of 69.9 x 76.2 mm (2.8 x 3.0 inches) with a 3.8:1 compression ratio.

On the scales, the Sport Twin measures 120 kg (265 lbs) dry. The 10-liter (2.6 US gal) fuel tank supports practical everyday commuting and weekend road stints.

Within MotoLibrary's Harley-Davidson archive, this model family spans 5 indexed model years from 1919 to 1923, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.

Engine

Displacement 590.0 ccm (36.00 cubic inches)

Engine Type Twin, four-stroke

Engine Details Twin, four-stroke

Compression 3.8:1

Bore x Stroke 69.9 x 76.2 mm (2.8 x 3.0 inches)

Fuel System Carburettor

Fuel Control Sidevalves

Ignition Magneto

Cooling Air

Transmission

Final Drive Chain (final drive)

Clutch Three speed

Chassis

Frame Type Tubular steel

Front Suspension Trailing link with single downtube

Rear Suspension Rigid

Wheels & Brakes

Front Tyre 3-26

Rear Tyre 3-26

Dimensions & Weight

Dry Weight 120.0 kg (264.6 pounds)

Fuel Capacity 10.00 litres (2.64 US gallons)

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Weight

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Fuel Capacity

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Suspension

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