What Is a Harley FXD?by Rob Wagner
The Harley-Davidson FXD Dyna Glide motorcycles belong to the FX series of custom Low Rider bikes. The Dyna line debuted in 1991, with the FXDB Dyna Glide Sturgis model. The Dyna was the motorcycle maker’s first computer-assisted designed bike that featured a new engine suspension system. That allowed the engine to vibrate at idle but smooth out while cruising. There were many variants of the FXD models.
The “F” in the FXD models designates that the bike features an overhead valve big twin engine, displacing 74, 80 or 88 cubic inches. The “X” designates the bike features sport forks and a narrow tire. “D” identifies the bike has having a “Dyna” frame and rubber-mounted engine to isolate vibration. FXD variants include “B” affixed to FXD to indicate a belt-drive bike or one painted black. “I” denotes fuel injection.
The FXD derived from the FXR motorcycle that ended production in 1995 and the 1970s FXS Low Rider. The new FXDL Dyna Low Rider, with a fat front tire, was actually a rebadged FXR, but with a new frame. The frame differed from other Harleys because it did not have a center tube bracing placed between the engine and transmission, but instead had a wreath of steel that encircled the engine and transmission for greater rigidity and to reduce road vibration.
The 1997 Harley-Davidson FXD Dyna Low Rider featured a V-Twin engine, displacing 1340 cc. It had a 3.498-inch bore and 4.250-inch stroke, 40 mm carburetor and accelerator pump, and five-speed constant mesh transmission. The Dyna sat on a 62.5-inch wheelbase, and the seat stood 26.5 inches tall. The fuel tank held 4.9 gallons and the bike’s dry weight was 598 pounds. The engine earned about 42 mpg. The 2001 FXD Dyna Super Glide boasted a 67-horsepower 1449 cc V-Twin engine and a five-speed belt-drive transmission. It was far heavier than the Dyna Low Rider, tipping the scales at 639 pounds. Both bikes featured the same wheelbase and measured 91 inches long. Ground clearance was a scant 5.4 inches.
The Dyna Super Glide models featured forward foot controls, a two-up seat and custom handlebar rider construction. By the end of the 1990s, virtually all traces of the FXS was gone. The FXDL version, for example, eschewed the FXS’s mag wheels that were a revolutionary feature in the 1970s for sports-laced wheels. Drag-styled handlebars also fell by the wayside for buckhorn-style handlebars.Super Glides in 2011 have a dual spark plug head, a higher compression ratio to boost torque, dual front disc brakes and adjustable suspension. They also feature a top-mounted speedometer and 28-degree steering head for more nimble handling on highway curves.