Built around Harley-Davidson's custom - cruiser motorcycle platform, the 2012 Harley-Davidson FLSTF Softail Fat Boy features a 1688 cc (103 cu in) air-cooled v2, four-stroke configuration. In factory specification, maximum torque reaches 133.8 Nm (98.7 lb-ft) at 3,000 rpm, transferring power to the rear wheel through a 6-speed gearbox and belt final drive. Internal engine geometry specifies a bore and stroke of 98.4 x 111.3 mm (3.9 x 4.4 inches) with a 9.6:1 compression ratio.
On the scales, the FLSTF Softail Fat Boy measures 328.9 kg (725 lbs) wet (curb). Rider ergonomics and chassis geometry center around a 635 mm (25 in) seat height — giving shorter riders and urban commuters confident flat-foot reach at traffic stops, combined with a 1,638 mm (64.5 in) wheelbase engineered for planted straight-line stability. The 18.93-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 4 indexed model years from 2007 to 2012, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Theoretical Range
~338 km (210 mi)
Engine
Displacement1688.0 ccm (103.00 cubic inches)
Engine TypeV2, four-stroke
Engine DetailsAir-cooled, Twin Cam 103B™
Torque133.8 Nm (13.6 kgf-m or 98.7 ft.lbs) @ 3000 RPM
Compression9.6:1
Bore x Stroke98.4 x 111.3 mm (3.9 x 4.4 inches)
Valves/Cylinder2
Fuel SystemInjection. Electronic Sequential Port Fuel Injection (ESPFI)
LubricationPressurized, dry-sump
CoolingAir
Transmission
Gearbox6-speed
Final DriveBelt (final drive)
ClutchMulti-plate with diaphragm spring in oil bath
DrivelinePrimary Drive Chain, 34/46 ratio. Final Drive Belt, 32/66 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)
ExhaustChrome, over/under shotgun exhaust with dual mufflers
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.
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.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
