Line of American motorcycles first manufactured in 1903 by William Harley and Arthur Davidson that are nowadays generally overpriced and underpowered.
Harleys are commonly referred to as "hogs," which is an allusion to the deep, throaty rumble the exhaust pipes emit as well as the amount of gasoline they typically consume. The loud exhaust noise is the basis for countless "all bark and no bite" references in relation to typical Harley engine performance. "Hog" is also an acronym for the Harley Owners' Group.
Harleys utilize the antiquated and inefficient V-twin engine design, which is a Harley trademark in much the same way tumors are a trademark of cancer victims. While even older V-twin engines boast an excellent amount of low-end torque, most V-twin engines redline at about 5000 to 6000 RPM which severely hampers any effort made to achieve quick acceleration. In contrast, many sportbikes redline at 10000 to 15000 RPM--double the amount of torque, which means you can accelerate harder for a longer period of time before having to change gears on a sportbike.
Despite advances in the construction of the V-twin engine, such as the 1450cc Twin Cam 88 (1999) and the 1130cc V-rod (2002), the fact of the matter is that neither engine design is worth their weight in gold because both still utilize the inefficient V-twin template. Granted, the current V-rod is a powerful and formidable engine that allows for much quicker acceleration than previous models and can hold its own against many low-end sportbikes, but Japanese (Honda, Kawasaki, Yamaha), Italian (Ducati) and German (BMW) manufacturers, using an array of different engine constructs such as the inline 4-cylinder design, have been outperforming Harley's outdated V-twin monstrosities for decades.
Once the mechanical horses of vicious outlaws such as the infamous Hell's Angels and a piece of machinery that commanded respect, Harley-Davidson motorcycles are now nothing more than something non-fleshy for pornographers to put between the legs of their models, as well as being status symbols for doctors, lawyers, and other yuppie scum who don't know the first goddamn thing about riding safely but will waste $20000-$30000 on a bike regardless. The aforementioned vicious outlaws can no longer afford to buy Harley-Davidson motorcycles, so they spend their time hanging out in sleazy bars and reminiscing over what could have been. Or they take the initiative and ride Hondas, like the gangs in the Charles Bronson movie "Death Wish."
In the late 1960s, Harley-Davidson was having many financial woes so they merged with recreation giant AMF. AMF produced, among other things, bowling balls and golf carts. AMF used the merger as an opportunity to slap the Harley logo on many non-motorcycle-related things they produced, such as their golf carts. So if someone ever says "my grandmother rides a Harley," they are probably being witty in referring to the fact that their grandmother (drives) an AMF-produced golf cart with the Harley logo emblazoned on it. (To be fair, Yamaha also produces golf carts and motorcycles, among other things but riding a Yamaha has never held the same amount of prestige as riding a Harley, so their reputation suffers little.)
Most Harley enthusiasts agree that while it was essential to the rebirth of the Harley-Davidson corporation, nothing good was produced during the merger of AMF and Harley. The bikes produced using AMF's resources were (by and large) crap, but many motorcycling enthusiasts would argue that some things never change. People bought the AMF-produced bikes though, which helped boost Harley-Davidson financially through the 70s as they competed against a flood of cheaper Japanese bikes entering the market. In 1981 Harley-Davidson and AMF split and Harley-Davidson became an independent company again.