| Component | Specification |
|---|---|
| Engine | Milwaukee-Eight 117 cui (1,923cc) |
| Oil Type | 20W50 Synthetic or Mineral (3.8 L) |
| Front Tire | 100/90B19 57H (36 psi / 2.48 bar) |
| Rear Tire | 150/80B16 77H (42 psi / 2.90 bar) |
| Battery | OEM P/N 66000207 |
| Spark Plugs | H-D 6-R12 |
The 2024-2025 Street Bob (FXBB/25) represents a significant milestone in Harley-Davidson’s Softail evolution. While the ‘Street Bob’ moniker originated in the 2006 Dyna lineup as a’stripped-down’ bobber, the FXBB/25 is the first standard-production Street Bob to be equipped with the Milwaukee-Eight 117 V-Twin as standard equipment. This engine was previously reserved for the high-tier CVO (Custom Vehicle Operations) and ‘Special’ models, effectively giving this lightweight chassis one of the highest power-to-weight ratios in the current Cruiser lineup.
Engineering Overview: The 117 Powertrain
At the heart of the FXBB/25 is the 1,923cc Milwaukee-Eight 117. This engine utilizes a precision oil/air-cooling system and a high-performance camshaft to deliver 125 ft-lb of peak torque. From a technical standpoint, the integration of the Heavy Breather intake as standard equipment ensures the 117-cubic-inch displacement is adequately fed, optimizing volumetric efficiency across the RPM range.
Maintenance Guide: Fluids & Lubrication
For the FXBB/25, thermal management is critical given the high displacement. MotoSpecsLab recommends a high-quality 20W50 motorcycle-specific oil. The total system capacity is 3.8 liters (4.0 US quarts). We suggest performing the initial break-in oil change at 1,000 miles (1,600 km) to remove any assembly particulates, followed by 5,000-mile intervals.
Chassis & Wheel Assembly
The Street Bob maintains its agile geometry using the redesigned Softail frame. Tire maintenance is paramount for handling precision. The front 19-inch wheel requires a 100/90B19 57H tire set to 36 psi, while the rear 16-inch wheel uses a 150/80B16 77H tire set to 42 psi. Deviating from these pressures can lead to ‘cupping’ on the front tread or wallowing in high-speed corners.
Electrical & Ignition
The FXBB/25 utilizes the 66000207 battery, providing high cold-cranking amps (CCA) required to turn over the large 117 pistons. For ignition, the H-D 6-R12 spark plugs are specified. Ensure the gap is checked every 10,000 miles to maintain optimal combustion efficiency and prevent misfires under high load.
Frequently Asked Questions
Q: Can I use 10W40 oil in the Street Bob 117?
A: While 10W40 can be used in colder climates, 20W50 is the manufacturer-recommended weight for the Milwaukee-Eight 117 to ensure adequate film strength at high operating temperatures.
Q: What is the benefit of the FXBB/25 over previous 114 models?
A: The 117 engine provides an approximate 5% increase in torque and features the high-flow Heavy Breather intake, which improves throttle response and mid-range acceleration.