The original FLHR Harley-Davidson Road King was powered by Harley-Davidson’s 1,340 cc Evolution V-Twin engine. The new Harley-Davidson Road King featured a host of upgrades over the Electra Glide it was replacing, including an improved wiring harness with waterproof connectors, detachable saddlebags and windshield, and taller gear ratios. Other features of the Harley-Davidson Road King included air-adjustable forks, dual front disc brakes, and a passenger seat that could easily be removed. So the Harley-Davidson Road King was positioned as a combination cruiser and touring machine.
In 1996 Harley-Davidson offered both the FLHR and FLHRI, the “I” indicating a Harley-Davidson Road King with fuel injection. The Weber Marelli fuel-injection system, standard on the 30th Anniversary Ultra Classic Electra Glide, allowed Harley-Davidson to pass California’s stringent emission system without adding catalytic converters to its bikes – better fuel mileage was an added benefit.
In 1999 the Harley-Davidson Road King, as well as other Harley-Davidson models, came from the factory powered by the new Twin Cam 88 engine. The engine’s name came from the addition of second cam to actuate the push rods for the opening and closing of the intake and exhaust valves, thus the new engine had two cams, one cam with two lobes for each cylinder’s two valves, compared to the Evolution engine’s use of a single cam with four lobes. The gears driving the cams in the Evolution engine were replaced with a chain in the Twin Cam engine. The 88 represents the displacement of the engine in cubic inches (1447cc). The engine also incorporated other improvements such as oil jets positioned to spray the bottom of the pistons to help cool the engine, and increased cooling fin area. In 2000 Harley-Davidson offered a 95 cu. in. big-bore kit that increased Twin Cam 88 engine displacement to 1550cc.
In 2004 the FLHRSI Harley-Davidson Road King Custom was introduced. The Custom featured leather hard bags, wide handlebars, a wind-swept headlight and lowered rear suspension. By 2007 it was time for another engine upgrade, this time being the Twin Cam 96. Same basic engine as the Twin Cam 88 but displacing 96 cubic inches (1584cc).
The Harley-Davidson Road King enters its 17th year of production in 2011 and, as with most Harley-Davidson models, the Road King remains largely the same as it was when introduced. The Road King is also widely used in police and fire departments in the United States as well as foreign countries.