The 2006 Harley-Davidson Road King is a classic touring model known for its versatility, featuring the 1450cc Twin Cam 88 engine, 5-speed transmission, fuel injection, and detachable windshield for cruiser-to-touring adaptability, with specific models like the Classic (FLHRCI) adding whitewalls and leather. Key aspects include air-adjustable rear suspension, dual front brakes, and common availability in carbureted or fuel-injected versions, though buyers should be aware of the potential for wear on the Twin Cam 88's cam chain tensioners, a known issue that often requires proactive maintenance or replacement.