| Specification | Data |
|---|---|
| Engine Type | Milwaukee-Eight 117 V-Twin |
| Oil Capacity / Grade | 4.7 L / SAE 20W-50 |
| Front Tire | 130/60B19 61H |
| Rear Tire | 180/55B18 80H |
| Tire Pressure (F/R) | 36 psi / 42 psi |
| Spark Plug | H-D 6-R10 |
| Battery Part No. | 66000174 |
Engineering Highlight: The ‘King of the Baggers’ Pedigree
The Harley-Davidson Road Glide ST (FLTRXST) represents a pivotal moment in the Motor Company’s history. While the Road Glide has long been a touring staple, the ‘ST’ designation signifies the first time Harley-Davidson successfully commercialized the ‘King of the Baggers’ racing DNA. Unlike standard touring models, the FLTRXST features a raised rear suspension and a frame-mounted Sharknose fairing that remains stationary during steering, significantly reducing aerodynamic interference and handlebar weight for high-speed stability.
Technical Performance: The Milwaukee-Eight 117
At the heart of this machine lies the 117 cubic inch (1,923cc) Milwaukee-Eight engine, previously reserved for CVO models. This powerplant utilizes a precision-cooled oil/air system and a high-performance Heavy Breather intake to deliver a staggering 127 ft-lb of torque. For the technical rider, this means a broader power band and enhanced thermal management under aggressive riding conditions.
Maintenance Guide & Essential Specifications
1. Lubrication System
The FLTRXST requires 4.7 Liters (approx 5.0 US Quarts) of high-viscosity SAE 20W-50 oil. MotoSpecsLab recommends synthetic fluids for the 117 engine to better handle the increased heat generated by the high-lift camshaft and increased displacement. Ensure the oil filter is replaced every 5,000 miles (8,000 km).
2. Tires and Chassis
Handling precision is contingent on maintaining strict tire pressure parameters. The 19-inch front wheel should be set to 2.5 bar (36 psi), while the 18-inch rear requires 2.9 bar (42 psi) to support the weight of the chassis and prevent cupping. The ST uses premium Dunlop Harley-Davidson Series bias-blackwall tires (130/60B19 front and 180/55B18 rear).
3. Electrical and Ignition
The ignition system utilizes Harley-Davidson 6-R10 spark plugs. Given the high compression of the 117 engine, gap checks should be performed during every major service. The electrical system is anchored by the 66000174 high-CCA battery, essential for turning over the massive V-twin pistons in cold weather.
MotoSpecsLab Verdict
The Road Glide ST (2022-2023) is a masterclass in performance-oriented touring. By stripping away the weight of a Tour-Pak and adding the raw power of the 117 engine, Harley-Davidson has created a motorcycle that demands expert-level maintenance but rewards the rider with unparalleled mechanical soul and highway dominance.