2009 Harley-Davidson FLSTF Fat Boy Technical Analysis & Specification Breakdown
At the heart of the 2009 Harley-Davidson FLSTF Fat Boy custom - cruiser motorcycle, Harley-Davidson relies on a 1584 cc (96.7 cu in) air-cooled v2, four-stroke powerplant. In factory specification, maximum torque reaches 120 Nm (88.5 lb-ft) at 3,300 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 95.3 x 111.1 mm (3.8 x 4.4 inches) with a 9.2:1 compression ratio.
On the scales, the FLSTF Fat Boy measures 313 kg (690 lbs) dry. Rider ergonomics and chassis geometry center around a 645 mm (25.4 in) seat height — giving shorter riders and urban commuters confident flat-foot reach at traffic stops, combined with a 1,635 mm (64.4 in) wheelbase engineered for planted straight-line stability. The 18.9-liter (5 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 1999 to 2011, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Standover Height
645 mm (25.4 in)
Engine
Displacement1584.0 ccm (96.66 cubic inches)
Engine TypeV2, four-stroke
Engine DetailsV2, four-stroke
Torque120.0 Nm (12.2 kgf-m or 88.5 ft.lbs) @ 3300 RPM
Compression9.2:1
Bore x Stroke95.3 x 111.1 mm (3.8 x 4.4 inches)
Fuel SystemInjection. Electronic Sequential Port Fuel Injection (ESPFI)
CoolingAir
Transmission
Gearbox6-speed
Final DriveBelt (final drive)
Clutch9-plate, wet
Performance
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.
