2017–2018 Harley-Davidson Touring Milwaukee-Eight 107 (FLHXS Street Glide Special)

The 2017–2018 Harley-Davidson Touring Milwaukee-Eight 107 (FLHXS Street Glide Special) represents a pivotal moment in the evolution of Harley-Davidson’s Grand American Touring lineup. Serving as the platform to launch the company’s ninth-generation Big Twin engine, the Milwaukee-Eight, this model brought significant advancements in performance, rider comfort, and refinement. The Street Glide Special variant, in particular, catered to riders seeking a blacked-out, factory-custom bagger aesthetic combined with modern technology and improved road manners, setting a new benchmark for the category.

The Milwaukee-Eight 107 Engine

The heart of the 2017-2018 Street Glide Special is the Milwaukee-Eight 107 engine. Named for its Milwaukee, Wisconsin origins and its eight-valve configuration (four valves per cylinder), this engine was a clean-sheet design intended to address the demands of modern riders while retaining the classic Harley-Davidson V-Twin character.

Key features of the 107-cubic-inch (1746cc) engine include:

Increased Power and Torque: The Milwaukee-Eight 107 produces approximately 10% more torque than the Twin Cam 103 engine it replaced, offering noticeably quicker acceleration.
Improved Heat Management: Through a combination of air cooling and precision oil or liquid cooling targeting the hottest areas around the exhaust valves, the engine dissipates heat more effectively. This results in greater comfort for the rider and passenger, especially in slow-moving traffic.
Reduced Vibration: A single internal counter-balancer cancels 75% of the engine’s primary vibration at idle. This provides a smoother experience at a standstill and on the highway, reducing rider fatigue without eliminating the signature V-Twin pulse that the brand is known for.
Enhanced Sound and Efficiency: A revised intake and exhaust system were designed to meet stricter global emissions and noise standards while producing a richer, more satisfying exhaust note. The engine is also mechanically quieter, allowing the iconic V-twin sound to be more prominent.

Key Differences from the Previous Twin Cam Model

The transition from the Twin Cam 103-powered Street Glide Special to the Milwaukee-Eight model in 2017 was more than just an engine swap. The new platform introduced comprehensive upgrades that addressed performance, comfort, and handling.

The most significant difference was the engine’s character. While the Twin Cam was beloved for its raw feel, the Milwaukee-Eight offered a more refined and powerful experience. The reduction in idle vibration was immediately apparent, making stops much more comfortable. The improved heat management was a direct response to rider feedback on the previous generation, especially in warmer climates. Furthermore, the single chain-driven camshaft of the Milwaukee-Eight simplified the valvetrain compared to the dual cams of its predecessor.

Chassis and Handling on the Milwaukee-Eight 107 (FLHXS Street Glide Special)

Alongside the new engine, Harley-Davidson introduced a completely revamped suspension system for its 2017 Touring lineup. The front suspension features Showa Dual Bending Valve (SDBV) fork technology, providing the damping performance of a high-end cartridge fork but with more linear characteristics and reduced weight. This results in a more controlled and comfortable ride, keeping the front wheel planted over various road surfaces.

The rear suspension was also significantly upgraded with new emulsion-technology shocks. Most notably, the preload adjustment range was increased, and adjustments could now be made via a single, tool-free hydraulic knob, making it far simpler for riders to set the suspension for a passenger or heavy luggage.

Styling and Features

The “Special” designation of the FLHXS model denotes its distinct styling. Unlike the chrome-heavy standard Street Glide, the Special features a blacked-out finish from front to back. The engine, exhaust, front forks, console, and handlebars are all finished in black, giving the bike a more aggressive and modern appearance. It also came standard with the premium Boom! Box 6.5GT infotainment system, featuring a full-color touchscreen, GPS navigation, and integrated audio, which was an upgrade on the standard model. The stretched saddlebags enhance the bike’s low-slung, custom profile while providing ample storage for touring.

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2017-2018 FLHXS Street Glide Special Specifications