1959 Harley-Davidson FLH Duo Glide Technical Analysis & Specification Breakdown
Positioned in Harley-Davidson's touring motorcycle lineup, the 1959 Harley-Davidson FLH Duo Glide features a 1212.7 cc (74 cu in) air-cooled v2, four-stroke configuration. In factory specification, peak output is rated at 55 HP (40.1 kW) at 4,800 rpm, transferring power to the rear wheel through a 4-speed gearbox and chain final drive. With a specific output of 45.4 HP per liter, the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.
On the scales, the FLH Duo Glide measures 304 kg (670 lbs) dry, translating to a power-to-weight ratio of 0.18 HP/kg (5.53 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,500 mm (59.1 in) wheelbase engineered for balanced agility and highway composure. The 14.19-liter (3.7 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Within MotoLibrary's Harley-Davidson archive, this model family spans 7 indexed model years from 1958 to 1964, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
45.4 HP/L
Power-to-Weight
0.18 HP/kg (5.53 kg/HP)
Engine
Displacement1212.7 ccm (74.00 cubic inches)
Engine TypeV2, four-stroke
Engine DetailsPanhead V-twin engine
Power55.0 HP (40.1 kW)) @ 4800 RPM
Compression7.0:1
Bore x Stroke87.0 x 102.0 mm (3.4 x 4.0 inches)
Fuel SystemCarburettor
Fuel ControlOverhead Valves (OHV)
CoolingAir
Transmission
Gearbox4-speed
Final DriveChain (final drive)
Chassis
Frame TypeTubular cradle
Front SuspensionHydraulic telescopic forks
Rear SuspensionSwingarm. Dual coil-over-shocks.
Wheelbase1500 mm (59.1 inches)
Wheels & Brakes
Front Tyre5.00-16
Rear Tyre5.00-16
Front BrakesExpanding brake (drum brake)
Rear BrakesExpanding brake (drum brake)
WheelsWire spoked
Dimensions & Weight
Dry Weight304.0 kg (670.2 pounds)
Power/Weight0.1809 HP/kg
Fuel Capacity14.19 litres (3.75 US gallons)
Oil Capacity3.70 litres (3.91 US quarts)
Other
StarterKick
Color OptionsBlack, red, blue, turquoise
Electrical6 Volt battery.
Notes
Windscreen. FLH models have higher compression then FL.
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
