The Harley-Davidson Fat Boy, is a V-twin softail cruiser motorcycle with solid-cast disc wheels.[2] Designed by Willie G. Davidson and Louie Netz, Harley-Davidson built a prototype Fat Boy in Milwaukee for the Daytona Bike Week rally at Daytona Beach in 1988 and 1989.[3][4] Fat Boys produced from 1990-2017 are coded FLSTF, and FLFB (& FLFBS) from 2018.
 | |
| Manufacturer | Harley-Davidson |
|---|---|
| Production | Since 1990 |
| Class | Cruiser |
| Engine |
1,868 cc (114 cu in) |
| Transmission | Chain (Primary) / Belt (final drive) |
| Brakes | Disc/disc |
| Wheelbase | 1,636 mm (64.4 in) |
An oft-repeated false etymology claims that the name comes from a contraction of Fat Man and Little Boy, the atomic bombs dropped on Japan during WWII, as a symbolic insult to Japanese motorcycles.[5] This has been debunked, as the name "Fat Boy" actually comes from the observation that the motorcycle is somewhat wider than other bikes when viewed head-on.[6][5] In a 2015 interview, Scott Miller, Harley-Davidson's vice president of styling and product development, confirmed that the name was simply descriptive and had nothing to do with Harley's Japanese competitors.[7]
History and development
In the mid-1970s, mechanical engineer Bill Davis designed and built a predecessor to the Softail and patented the design in 1976.[8] Davis sold his patents, prototype, and tooling to Harley-Davidson in January 1982.[9] The Fat Boy was one of numerous Harley-Davidson models built on the Softail frame.
- After 1994, the exhaust was made seamless.
- In 1996 the master cylinder and switch gear were revised.
- In 1999 a new 1,450 cc (88 cu in) Twin Cam engine for the 2000 model year was used. This necessitated a bespoke engine variant and changes to the frame.
- In 2002 bullet-style indicators, alarm and immobilizer were added.[10]
- In 2005 a 15th Anniversary version was sold with a "Screamin' Eagle" engine, special paint and custom wheels.[10]
- In 2007 the displacement was increased to 1,584 cc (96.7 cu in)[10] and the transmission changed six speeds.[11]
- The 2010 "Fat Boy Lo" FLSTFB had the lowest ever Harley seat height.[2]
- In 2012 the Fat Boy received the new 1,690 cc (103 cu in) Twin Cam engine along with the rest of the softail range
- 2018 Fat Boys have a redesigned softail frame with Showa front and rear suspension and new twin-counterbalanced Milwaukee-Eight engines. The two 2018 variants comprise:
- FLFB 1,746 cc (107 cu in) with 109 lb⋅ft (148 N⋅m), and
- FLFBS 1,868 cc (114 cu in) with 119 lb⋅ft (161 N⋅m)[12]
The 2018 Softail frame has a modified swingarm with a Showa rear monoshock suspension mounted beneath the seat, replacing earlier twin shocks. So as to provide a more comfortable and better controlled ride with improved handling, the front forks contain a Showa "Dual Bending Valve" (SDBV),[13] a cartridge simulator using two valves to control compression and rebound damping, giving linear damping characteristics proportional to fork stroke speed. Harley-Davidson claims the 2018 chassis is stiffer and lighter than earlier Softail and Dyna platforms.[14] Further upgrades include an LED headlight and 18-inch "Lakester" rims, with wider 160mm front and 240mm rear tires.[15][16]
For 2020, the Fat Boy is only available with the Milwaukee-Eight 114 engine. Harley-Davidson also produced a 30th Anniversary edition for 2020.[17]
It is one of Harley-Davidson's best selling models and has appeared prominently in a number of TV shows and movies.[3] The Fat Boy earned a place in American pop culture after appearances in the movie Terminator 2: Judgment Day. One of the motorcycles used in Terminator 2 is displayed at the Harley-Davidson Museum. It appeared again in Terminator Genisys.[2][18][7][19]
