Sun Coast Cycle Sports carries inspected used parts for the 2018-2020 Harley-Davidson FXBB Street Bob equipped with the Milwaukee-Eight 107 engine (1753cc). This model represents the first Street Bob on the completely redesigned 2018 Softail platform, which replaced both the previous Softail and Dyna chassis families. Our technicians in Florida photograph and catalog each component individually, assigning unique SKUs before listing with free shipping throughout the continental United States.
Street Bob FXBB 107ci generation and parts compatibility
The 2018 model year brought a complete Softail platform redesign. The new chassis is lighter and more rigid than the previous generation, featuring a single rear shock mounted beneath the seat and a solid-mounted Milwaukee-Eight engine. This represents a significant break from both the previous Twin Cam Softail (2000-2017) and the Dyna platform that also used the Street Bob name (FXDB, 2006-2017).
| Platform | Years | Engine | Model Code |
|---|
| Dyna Street Bob | 2006-2017 | Twin Cam 96/103 | FXDB (NOT compatible) |
| M8 Softail Street Bob | 2018-2020 | Milwaukee-Eight 107 | FXBB (this page) |
| M8 Softail Street Bob | 2021+ | Milwaukee-Eight 114 | FXBBS (different displacement) |
The 2018+ Softail chassis is shared across multiple models including the FXLR Low Rider, FXFB Fat Bob, FLSB Sport Glide, FLSL Softail Slim, FLHC Heritage Classic, and FXST Standard. Frame, swingarm, rear suspension components, and most chassis hardware interchange across all 2018+ Softail models regardless of engine displacement. The Milwaukee-Eight 107 and 114 share external engine dimensions and mounting points, so accessories, exhaust systems, and engine covers typically fit both displacements.
Critical distinction: The 2006-2017 FXDB Dyna Street Bob shares only the Street Bob name with the 2018+ FXBB. These are completely different platforms with zero parts interchange for frame, chassis, engine, and transmission components.
Common Street Bob FXBB 107ci failure points and replacement parts
Oil sumping issue (2018-early 2019): Early Milwaukee-Eight Softail models experienced an oil sumping condition where oil accumulates in the crankcase rather than returning to the oil tank. Harley issued Service Bulletin M1450 addressing this issue. Symptoms include power loss during extended high-RPM riding, oil blowing back through breathers, and low oil tank level with high crankcase level. Bikes built after late May 2019 received an updated oil pump assembly and revised primary case vent system. Earlier bikes can be retrofitted with the updated components.
Primary-to-transmission fluid migration (early 2019): Some early 2019 models experienced fluid transfer between the primary and transmission compartments through the mainshaft seal area. Harley addressed this with a revised primary case vent routing. The symptom is transmission oil level rising while primary level drops.
Compensator noise: Like previous Harley Big Twins, the Milwaukee-Eight uses a compensator in the primary drive. Some owners report clunking on deceleration. Aftermarket compensator upgrades are available for those who find the noise objectionable.
Exhaust header discoloration: The factory header pipes can develop blue or gold discoloration from heat cycling. This is cosmetic only and does not affect performance or durability.
Throttle-by-wire surge: Some riders report a slight surge or hesitation at very low throttle openings, particularly in traffic. This is a characteristic of the electronic throttle calibration rather than a defect. Some aftermarket tuners can adjust the throttle mapping.
Commonly replaced Street Bob FXBB 107ci parts
- Oil pump assembly (updated version for sumping fix)
- Primary case vent components
- Compensator sprocket
- Exhaust system and heat shields
- Handlebars and risers
- Forward control mounting hardware
- Brake pads and rotors
- Mirrors and hand controls
Frequently asked questions
Q: Will parts from a 2006-2017 FXDB Dyna Street Bob fit my 2018+ FXBB?
No. The Dyna and new Softail platforms are completely different chassis designs with different engines. The 2006-2017 FXDB used the Twin Cam engine on the Dyna rubber-mount frame. The 2018+ FXBB uses the Milwaukee-Eight engine on the redesigned Softail chassis. Frame, engine, transmission, swingarm, and suspension components do not interchange. Some accessories like grips, mirrors, and lights may fit both, but verify compatibility before ordering.
Q: Are 2018-2020 FXBB 107ci parts compatible with 2021+ FXBBS 114ci models?
Most chassis and accessory components interchange between the 107 and 114 Softail Street Bobs. Frame, swingarm, suspension, wheels, brakes, bodywork, and electrical systems are shared. Engine external components including exhaust, air cleaner, and covers typically fit both. Engine internals (cylinders, pistons, heads) differ between the 107 and 114 due to the different bore sizes. The 114 uses 4.016-inch bore cylinders versus 3.937-inch on the 107.
Q: What other 2018+ Softail models share parts with the Street Bob?
All 2018+ M8 Softails share the same basic chassis architecture. The FXLR/FXLRS Low Rider, FXFB/FXFBS Fat Bob, FLSB Sport Glide, FLSL Softail Slim, FLHC Heritage Classic, FLDE Deluxe, and FXST Standard share frame, swingarm, rear shock mounting, and most mechanical components with the Street Bob. Model-specific items include fuel tanks, fenders, seats, handlebars, and cosmetic covers. Docking hardware for accessories uses the same mounting points across all models.
Inspected by Powersports Technicians • Only One in Stock • Ships Fast from Florida
