Softail Fat Boy Base FLSTF (2015): Motoplanete's Own Verdict — Bigger Bars, Better Brakes, and "Even More 'Fat'"
Motoplanete's own French road test frames the platform's genuine handling evolution directly: "the adoption of the 103B twin-cylinder engine is more in keeping with this big custom than ever. More torque, more power, more 'fat' everywhere, as well as smoother vibrations thanks to a balancing weight... a 200mm rear tire doesn't make agility any easier, but it does give the 'Boy' even more 'Fat.' Docile thanks to its wide, larger handlebars (which integrate the wiring), you have to be reasonable, as too much angle quickly files the wide running boards." That same review confirms genuine, real performance figures for this exact model year: a top speed around 160 km/h (99.4 mph) and peak torque of 13.4 mkg (134 Nm) at 3,250 rpm.
Power comes from the air-cooled Twin Cam 103B, a 1,690cc counter-balanced V-twin, black powder-coated, with a 3.87-inch bore and 4.374-inch stroke and a 9.6:1 compression ratio, fed by Electronic Sequential Port Fuel Injection, run through a 6-speed Cruise Drive transmission with belt final drive and a 34/46-ratio chain primary. TotalMotorcycle's own confirmed dealer copy captures the model's whole design philosophy: "the Fat Boy model is the very definition of a heavyweight motorcycle, delivering a bold styling statement and a wide, comfortable riding stance," with an optional Engine Idle Temperature Management Strategy (EITMS) available as a genuine dealer-activated feature for hot-weather riding comfort.
Eisenhauer's Tioga County Harley's own confirmed factory spec sheet — explicitly badged "Base" trim, matching your listing — lists a 31-degree rake with 5.8 inches of trail on a 64.4-inch wheelbase, a 25-inch laden seat height (27.2 inches unladen), and 5.1 inches of ground clearance, riding on 140/75R17 front and 200/55R17 rear tires. Standard ABS and the model's signature bullet-hole solid-disc aluminum wheels carried through this exact configuration, backed by a horseshoe oil tank and five-gallon fuel tank.
Confirmed fluid capacities list a 5-gallon fuel tank and 3.5 quarts of oil (with filter), with shipped weight at 694 lbs rising to 725 lbs in running order. 2015 US pricing started at $17,699 for Vivid Black. This exact FLSTF Base configuration ran through 2017 before Harley's 2018 Softail platform redesign renamed the model FLFB (107ci) and FLFBS (114ci) on the new single-shock chassis.
This factory service manual covers the procedures, torque specs, and diagrams needed to keep a 2015 Softail Fat Boy Base FLSTF running the way it was built to.
