2015 Harley-Davidson Softail Fat Boy Special Technical Analysis & Specification Breakdown
Positioned in Harley-Davidson's custom - cruiser motorcycle lineup, the 2015 Harley-Davidson Softail Fat Boy Special pairs a 1690 cc (103.1 cu in) air-cooled v2, four-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 77.8 HP (56.8 kW) at 5,250 rpm while maximum torque reaches 132 Nm (97.4 lb-ft) at 3,250 rpm, transferring power to the rear wheel through a 6-speed gearbox and belt final drive. With a specific output of 46 HP per liter and a 2,000 rpm working window between peak torque (3,250 rpm) and peak power (5,250 rpm), the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.
On the scales, the Softail Fat Boy Special measures 332 kg (732 lbs) wet (curb), translating to a power-to-weight ratio of 0.23 HP/kg (4.27 kg per horsepower). Rider ergonomics and chassis geometry center around a 670 mm (26.4 in) seat height — giving shorter riders and urban commuters confident flat-foot reach at traffic stops, combined with a 1,630 mm (64.2 in) wheelbase engineered for planted straight-line stability. The 18.9-liter (5 US gal) fuel tank paired with a rated consumption of 5.6 L/100 km provides an estimated theoretical range of roughly 338 km (210 miles) between fill-ups.
Within MotoLibrary's Harley-Davidson archive, this model family spans 3 indexed model years from 2013 to 2016, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
46 HP/L
Power-to-Weight
0.23 HP/kg (4.27 kg/HP)
Power Band Window
3,250–5,250 rpm
Theoretical Range
~338 km (210 mi)
Engine
Displacement1690.0 ccm (103.12 cubic inches)
Engine TypeV2, four-stroke
Engine DetailsAir-cooled, Twin Cam 103B™
Power77.8 HP (56.8 kW)) @ 5250 RPM
Torque132.0 Nm (13.5 kgf-m or 97.4 ft.lbs) @ 3250 RPM
Compression9.6:1
Bore x Stroke98.4 x 111.3 mm (3.9 x 4.4 inches)
Fuel SystemInjection. Electronic Sequential Port Fuel Injection (ESPFI)
CoolingAir
Transmission
Gearbox6-speed
Final DriveBelt (final drive)
ClutchMulti-plate with diaphragm spring in oil bath
DrivelinePrimary chain, 34/46 ratio
Performance
Fuel Consumption5.60 litres/100 km (17.9 km/l or 42.00 mpg)
Greenhouse Gases129.9 CO2 g/km. (CO2 - Carbon dioxide emission)
ExhaustDenim Black and Satin Chrome, over/under shotgun exhaust with dual mufflers
Chassis
Rake31.6°
Trail147 mm (5.8 inches)
Wheelbase1630 mm (64.2 inches)
Ground Clearance125 mm (4.9 inches)
Wheels & Brakes
Front Tyre140/75-R17
Rear Tyre200/55-R17
Front BrakesDouble disc. 4-piston. ABS.
Rear BrakesSingle disc. 2-piston
WheelsBlack, Bullet Hole Disc Cast Aluminum
Dimensions & Weight
Dry Weight318.0 kg (701.1 pounds)
Weight incl.332.0 kg (731.9 pounds)
Power/Weight0.2446 HP/kg
Seat Height670 mm (26.4 inches) If adjustable, lowest setting.
Overall Length2385 mm (93.9 inches)
Fuel Capacity18.90 litres (4.99 US gallons)
Oil Capacity3.30 litres (3.49 US quarts)
Other
StarterElectric
Color OptionsCharcoal Pearl, Radioactive Green, Sand Cammo Denim, Black Denim, Vivid Black
InstrumentsTank-mounted electronic speedometer with odometer, time-of-day clock on odometer, dual tripmeter, RPM/gear display, fuel gauge with low fuel warning light and countdown feature, low oil pressure indicator light, engine diagnostics readout, LED indicator lights, 6-speed indicator light
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.
Torque
Torque is useful for judging real-world pull, especially for touring, commuting and loaded riding.
Seat Height
Check the seat height against your inseam and riding posture before choosing a motorcycle.
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.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.