How A Harley-Davidson Works

This article examines the basic engine configurations, suspension specifications and allure of the Harley Davidson motorcycle.

For some people the rumble of a V-Twin engine isn't just another internal combustible engine, it's an American signature. There's nothing quite like the noise a Harley Davidson makes as it cruises up and down a boulevard.

Other companies have made V-Twin motorcycles, and Harley Davidson isn't the only manufacturer of metric cruisers in operation today, but there's just something special about a big, air-cooled, American-built V-Twin. When Indian Motorcycles rose from the ashes in the 1990s, it was Harley Davidson it set its sights on, using a SS version of an old air-cooled V-Twin, but Harley wasn't the only American company to use this engine design. Over the years Iver Johnsons, Indians, Cyclones, Crockers and other have used this design with varied levels of success.

The V-Twin seems to epitomize the spirit of the United States in the way Triumph's parallel twin used to seem exquisitely British.

Harley Davidson motorcycles have changed remarkably little over the years. Manufacturing standards have improved, and the bikes now use vibration-dampening rubber pieces to quell the natural shake of the machine, but heart the beats between the bike's wheels remains largely the same as it has for decades.

Harley offers everything from entry-level bikes such as the Sportsters 883 to the venerable Road King. Unlike manufacturers like Honda, however, Harley Davidson plays to the same niche in each of its bikes: Those wanting an American classic.

The Fat Boy is a better tour bike than the Dyna Glide, but neither are playing in the same ballpark as Honda's Goldwing, and Harley riders wouldn't want it any other way. You might buy a Kawasaki Ninja because you want a sportbike, but you buy a Harley because you can't live with anything else.

So what makes Harley Davidsons so special? Let's start at the engine. A 45-degree, pushrod, air-cooled V-Twin is a rather primitive engine design, prone to vigorous vibrations. The positioning of the cylinders in a "V" shape means that air doesn't easily circulate around the rear-most cylinder, which can lead to overheating. On the other hand, this engine produces impressive torque low in the power band, where it can be easily accessed on the street.

Although the basic design has undergone gradual changes throughout the years, Harley had not radically changed it's design until the release of the radical liquid-cooled, V-Rod in 2002. This means that the Harley you get today will feel a lot like the one your dad bough in the late 1960s, but with one big difference - quality control. Today's Harleys will slightly outperform those of yesterday, but in terms of reliability it's night and day.

Harley Davidson uses traditional frames and suspension parts, including double rear shocks. Long, low and relaxed, Harleys have conservative steering geometry and rather narrow spoked rims. Being so low to the ground allow the machines to appear far lighter than what they actually are, which makes the Sportster 883 particularly popular with women and smaller riders. .

While Harley's Sportster might seem a bit of a misnomer when compared to today's hyper sport 600s, the larger touring bikes""such as the Road King - are accomplished long haul machines combining comfort, charisma, reliability and useful power. Featuring a 1450cc Vee, the Big Twins are a joy on a bit of open desert road or traversing the country via highways.

The Dyna Glide and Sportster models are excellent all-purpose machines. Although they cannot compete with Harley's top tour models, it's not uncommon to find beautifully detailed softails making the trip from coast to coast. The Sportster 883 is one of the best city bikes in production, combining the feeling of lightweight with good power delivery and real panache.

One of the things Harley owners prize most is the vigorous aftermarket industry that allows them to customize their machines in any number of ways. Virtually every piece of bodywork, engine component or suspicion part can be dialed in using aftermarket suppliers. Harley Davidsons can be transformed into café racers, rat bikes, flat trackers, choppers or ultimate cruisers with the addition of just a few select parts.

And this is the real magic of the machine: Like America, Harley Davidsons adaptable, stubborn and full of character.

© High Speed Ventures 2011