| MODEL | HARLEY-DAVIDSON SOFTAIL FAT BOY 2015 |
| Year | 2015 |
| Engine Type | Four stroke, V-twin, Twin Cam 103B, pushrod-operated OHV with hydraulic self-adjusting lifters, 2 valves per cylinder, integrated oil cooler |
| Displacement / Capacity | 1690 cc / 103.1 cu in |
| Bore X Stroke | 98.4 x 111.1 mm |
| Compression Ratio | 9.6:1 |
| Cooling System | Air cooled |
| Max Power | 56.8 kW / 77.8 hp @ 5250 rpm |
| Max Torque | 134 Nm / 98.8 lb-ft @ 3500 rpm |
| Ignition | Single-fire, non-wasted, map-controlled spark ignition |
| Induction | Electronic Sequential Port Fuel Injection (ESPFI) |
| Start System | Electric |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 6-speed |
| Clutch | — |
| Final Drive | Belt |
| CHASSIS SPECS | |
| Frame | Mild steel tubular frame, rectangular-section backbone, stamped, cast and forged junctions, forged fender supports, MIG welded |
| Front Suspension | 41.3 mm telescopic fork, chrome dust covers |
| Rear Suspension | Hidden, horizontal-mounted coil-over shocks |
| Front Brakes | Disc, 4-piston caliper |
| Rear Brakes | Single disc, 2-piston caliper |
| DIMENSION SPECS | |
| Overall Length | 2396 mm / 94.3 in |
| Overall Width | — |
| Overall Height | — |
| Seat Height | 635 mm / 25.0 in (laden), 690 mm / 27.1 in (unladen) |
| Wheelbase | 1635 mm / 64.2 in |
| Ground Clearance | 130 mm / 5.1 in |
| Dry Weight | 313 kg / 690 lbs |
| Wet Weight | 329 kg / 725 lbs |
| WHEEL SPECS | |
| Front Tyre | 140/75R17 67V |
| Rear Tyre | 200/55R17 78V |
| FUEL SYSTEM | |
| Fuel Capacity | 18.9 Litres / 5.0 US gal |
| Fuel Consumption | 5.6 L/100 km / 42 US mpg |
| Top Speed | — |
The 2015 Fat Boy uses the 1690 cc Twin Cam 103B, the larger counterbalanced engine that came to the Fat Boy for 2012 along with the rest of the Softail family. The formula is otherwise the classic one: hardtail look with hidden shocks, 140 mm front and 200 mm rear tyres on solid bullet-hole wheels, wide bars, footboards and a six-speed Cruise Drive gearbox for low highway revs. The 2015 bike carried on with a two-piece seat and removable passenger pillion, ABS and the optional keyless security system.
