| Specification | Detail |
|---|---|
| Model | Road King Special 114 (FLHRXS) |
| Production Years | 2021-Present |
| Engine Type | Milwaukee-Eight 114 V-Twin |
| Oil Type | SAE 20W50 (HD 360 or SYN3) |
| Oil Capacity | 3.8 Liters (4.0 US qt) |
| Spark Plugs | 6R10 |
| Battery | 66000174 |
Engineering Highlight: The 2021 update to the Road King Special (FLHRXS) represents a pivotal moment in Harley-Davidson’s engineering history. To meet stringent Euro 5 emissions standards without sacrificing the raw torque of the 114ci Milwaukee-Eight engine, engineers implemented a sophisticated dual-sensor exhaust system and recalibrated the ECM to manage heat more effectively. This ensures the bike retains its iconic “thump” while complying with modern global environmental regulations.
Technical Overview: The King of the Road
The Road King Special 114 is the dark, aggressive sibling of the classic touring line. Stripped of chrome and the traditional windshield, the FLHRXS focuses on performance. The Milwaukee-Eight 114 engine delivers 118 ft-lb of torque, providing effortless passing power even when fully loaded. The Euro 5 variant features a revised air intake and exhaust system to optimize the combustion cycle.
Chassis and Handling
Despite its massive presence, the Road King Special utilizes high-performance front and rear suspension with easily adjustable rear shocks. The Prodigy cast aluminum wheels (19-inch front, 18-inch rear) are paired with Reflex Linked Brembo Brakes, offering superior stopping power and ABS as standard—essential for a machine of this mass.
Maintenance Guide & Specifications
Lubrication System
For the Milwaukee-Eight 114, oil choice is critical for heat dissipation. Use SAE 20W50. While Harley-Davidson 360 Mineral oil is sufficient, MotoSpecsLab recommends the SYN3 Synthetic for better performance in high-temperature stop-and-go traffic. The total capacity is 3.8 liters.
Tires and Traction
Maintaining correct tire pressure is vital for the FLHRXS’s handling geometry. The factory-recommended settings are:
- Front: 130/60B19 61H – 2.5 bar (36 psi)
- Rear: 180/55B18 80H – 2.8 bar (40 psi)
Electrical and Ignition
The ignition system relies on 6R10 spark plugs. These should be inspected every 5,000 miles for carbon buildup. The electrical heart of the machine is the 66000174 battery, which provides the high cold-cranking amps (CCA) required to turn over the high-compression V-twin.
MotoSpecsLab Verdict
The Road King Special 114 (Euro 5) is a masterclass in balancing heritage with modern necessity. It remains one of the most mechanically “pure” touring bikes on the market, offering a visceral riding experience backed by contemporary safety technology.