| Component | Specification |
|---|---|
| Production Years | 2015–2023 |
| Engine Types | Milwaukee-Eight (M8) / High Output Twin Cam 103 |
| Oil Type | SAE 20W50 HD 360 or SYN3 |
| Front Tire | 130/60B19 61H (36 psi / 2.5 bar) |
| Rear Tire | 180/55B18 80H (40 psi / 2.8 bar) |
| Battery Part | 66000101 |
| Spark Plug | 6R10 (Gap: 0.030″) / 6R12 (Gap: 0.038″-0.043″) |
Engineering Highlight: The Aerodynamic Sharknose
The defining characteristic of the Road Glide Special (FLTRXS) is its frame-mounted ‘Sharknose’ fairing. Unlike the Batwing fairing found on the Street Glide, which is mounted directly to the forks, the Road Glide’s fairing remains stationary during steering. This engineering choice, which traces its lineage back to the 1980 FLT Tour Glide, significantly reduces steering inertia and prevents wind buffeting from being transferred to the handlebars, offering superior stability at high highway speeds.
Maintenance Deep Dive
Lubrication System
For the FLTRXS, lubrication requirements shifted significantly with the introduction of the Milwaukee-Eight engine in 2017. Earlier Twin Cam models (2015-2016) require approximately 2.8 to 3.3 liters of oil. The newer M8 variants require a larger volume, typically 4.0 to 4.3 liters, to accommodate the increased cooling demands of the four-valve cylinder heads. MotoSpecsLab recommends using Harley-Davidson SYN3 for high-temperature stability in heavy touring conditions.
Chassis and Contact Patch
The Road Glide Special utilizes a low-profile wheel setup that demands precise pressure management. The front 19-inch wheel (130/60B19) must be maintained at 36 psi to ensure crisp turn-in, while the rear 18-inch wheel (180/55B18) requires 40 psi to support the weight of the chassis and potential passenger/luggage loads. Failure to maintain these pressures can lead to uneven tire cupping, a common issue on heavy touring platforms.
Electrical and Ignition
The electrical system is anchored by the 66000101 battery, providing the high cold-cranking amps (CCA) necessary to turn over the high-compression V-Twin. For ignition, spark plug selection depends on the specific engine year: the 6R10 requires a tight 0.030″ gap, while the 6R12 allows for a wider 0.038″-0.043″ gap. Proper gapping is critical to prevent hesitation under load.
MotoSpecsLab Verdict
The FLTRXS remains the benchmark for long-distance performance touring. Its combination of frame-mounted aerodynamics and the robust Milwaukee-Eight powertrain (in later models) makes it a technician’s favorite for its accessibility and predictable maintenance intervals. Adhering to the specific fluid capacities and tire pressures listed above is essential for preserving the ‘Special’ handling characteristics of this machine.