Harley-Davidson Fat Boy Parts & Accessories

Fat Boy parts: it starts with the year

There are more Fat Boys on UK roads than any other Harley: about 3,500 taxed, and nearly as many again laid up on SORN. Around two in three were built before 2018, and that year decides most of what you can order.

Harley replaced the entire Softail frame for 2018. Across the two generations we list just over a thousand genuine accessories, and only 405 of them fit both. Service items, mirrors, fuel caps and most security kit carry over. Parts that bolt to the frame mostly don’t: five of the thirty seat and backrest parts cross the line, three of 109 Screamin’ Eagle parts, and none of the windscreens.

From 2021 to 2024 the Fat Boy was sold only as the 114, so if your bike is from those years it is the 114 page you want.

Sissy bars and racks

The two generations use different mounting systems with similar names, so check the part number rather than the description. A 1990–2017 bike takes H-D Detachables sideplates (53810-00D) on docking kit 53930-03B. A 2018-on bike takes HoldFast uprights, 52300437 in chrome or 52300439 in black, on the HoldFast docking kit 52300643 or 52300644. The uprights won’t go on without the docking kit, and the listings don’t always say so. Racks follow the upright, so choose the sissy bar first and the luggage rack to suit it.

Made only for the Fat Boy

The 2018-on bike has its own headlamp nacelle kit (61300811, 61300817), a Sundowner solo seat (52000293) with a matching pillion (52400170), and Seismic 18-inch wheels. Its rear tyre is a 240/40R18, a size very few bikes share, so the choice is narrow; the genuine fitment is the Michelin Scorcher 43189-11. Older bikes changed size twice: a 200/55R17 rear from 2007 to 2017, a 150/80B16 for 2003 to 2006, and MT90B16 before that. For the older bike there is also a stainless Fat Boy handlebar, 55919-01.

What goes out of the door

Of everything we sell that fits a Fat Boy, the big sellers are small parts: locking fuel caps in chrome and black, the Willie G skull shifter peg and footpegs, Signature LED front indicators and the single-sided swingarm bag.

Close relatives

The 2018-on Breakout sits on the same frame and is the nearest thing to a Fat Boy in the parts book: 619 of the 639 genuine accessories we list for it also fit the Fat Boy, the 240 rear tyre included. The Heritage Classic shares 653 parts with it and comes with the bags and screen already on.