Launched in 1957, Harley-Davidson’s Sportster model entered its 63rd year of continuous production this year. While many manufacturers create an illusion of heritage by merely carrying an established model name forward, the Sportster is unique because it has genuinely evolved, year by year. Comparing the engine and chassis layout of a 21st century Sportster with one from the 1960s, the component parts may not be identical but they certainly look very similar and are located in pretty much the same position.
The Sportster’s genes go back even earlier, to the 1952 Model K, Harley’s first machine with foot gearchange and swinging arm rear suspension. While the K’s styling was popular, its underpowered side-valve engine was not. The Sportster replaced the K’s side-valve arrangement with overhead valves, increasing the top speed from around 80mph to over 90, enough to keep the rapid 650s from England in sight, if not quite enough to catch them.
The first Sportsters used an air-cooled 883cc 45-degree vee-twin with the air cleaner and exhaust dominating the styling on the right hand side of the machine and the primary transmission on the left. This arrangement is still current today. Over the years, details have changed: electric start has been added; coil ignition replaced magneto; disc brakes replaced drums; fuel injection replaced carburetion; various sizes of fuel tank and seat have been offered, but the fundamentals have remained the same. Along the way, the engine grew from 883 to 1000cc, back to 883 then up to 1100 and finally 1200.
The two major changes to the Sportsters came in 1986 and 2004. For almost 30 years, the Sportster engine used iron heads and barrels; the Evo (short for Evolution) engines which arrived in 1986 switched to aluminium which transformed the reliability. Now the engines ran cooler with fewer oil leaks and much reduced maintenance requirements. Before the Evo, only ‘die hard’ enthusiasts ran Sportsters; from 1986 anybody could enjoy one.
The last big change came in 2004 when the engines became rubber mounted, like the bigger Harleys. This resulted in a heavier motorcycle but successfully overcame the vibration which had always limited the Sportster’s usability for high speed, long distance riding. The styling of the external engine covers was tweaked at the same time but the mechanicals were largely carried over; as an example, Harley Davidson has been using the current 2020 engine oil filter since the 1984 iron head engines.
Unlike many of today’s ‘retro’ motorcycles, the Harley Sportsters can legitimately claim to be the real thing in so far as they can trace their ancestry directly back to the 1950s. Up to the early 1970s they were genuine hot rods and though eclipsed since then in both engine and chassis performance, they still offer the charm and individuality of a big lazy engine with instant torque available on demand. The huge aftermarket supplier base for custom accessories means that finding an older bike in original condition can be a challenge but many consider the factory spec is just a ‘blank canvas’ anyway, on which they can create their own vision of perfection.