All in the name of sport?
The American way of doing things
When the Sportster was first introduced back in 1957, performance wise, at least, there was little around to touch it. With a genuine top speed a shade over the magical ton and very good low down acceleration, Harley were at the forefront of the game. The type, albeit much developed, is still around today and we take a look at an example from the back end of the 70s.
The Sportster may have been staggeringly fast, however, the chassis did leave a little to be desired, and there can be no doubt the Italians, British, and the later Japanese models, have led the field in this respect throughout the Sportsters life.
Many years ago frame designers hit on the idea of triangular forms being the strongest and least flexible, especially as the power outputs of machinery grew and grew. Unfortunately this information didn’t filter down to the HD design crew and the Sportster frame resembles more of a square when viewed from the side than anything with three sides. Ducati would have embalmed the V-twin in a steel trellis, while the Japs would have nailed it firmly in place with a variety of hefty beams and tube work, but not HD. Scant regard has been played to handling throughout the life of the Sportster. Harley also missed out on a great opportunity, usually when a frame builder is faced with a larger, bulky and yet strong engine they incorporate it into the frame itself, this way the rigidity of the tube work can be enhanced while keeping important mounting points as close together as possible. Did they achieve this with the iron head? Not a chance, the thin tubing meanders its way around up, and over, the big V-twin while the headstock is left to get on with the job of holding the front end in place, distanced far away from the swing arm pivot. The Sportster has a more laid back approach to the art of travelling at speed. While its 45-degree, 1000cc v twin engine is always willing to go, and is quite revvy too, the chassis is not so keen to play ball and any attempt to make it so will yield nothing but contempt. Unlike most other machines, whose chassis are constantly working to get one task done while looking forward to the next, the Harley Sportster always feels to be two steps behind the action.
From the moment the starter button is pressed the Sportster doesn’t feel quite like any other motorcycle either, the two cylinders appear to fire, sometimes in, but mostly out of, synchronisation. Even on the move the engine never does settle into a happy rhythm although there is a definite sweeter spot around the 4000rpm mark. This does give the impression of being more a part of the proceedings, and has to be sampled to be fully understood, its like taking a step back in time to the days of leather helmets and goggles.
The ride is relaxed and definitely un hurried. This isn’t a bad thing as the steel work that makes up the frame is supple and not at all rigid. Even with the loose feel of the chassis, the biggest problem is shifting the dead weight created by the iron top end of the engine. The brakes look small and weedy, not at all capable of stopping the heavy machine in a safe distance from high speed, that is, until you throw the engine into the equation. Constant downshifts throughout the stopping process keep the brakes honest, making what could be a dangerously under braked machine into a competent stopper. In the dry they are just about adequate with the rear more powerful than the front two, in the wet however things change drastically and the wait, following the initial activation for the brakes to get going, is heart stopping, to say the least.
The engine is incredibly narrow and svelte, however, the unit is placed high up in the chassis making the heaviest part at the very top of the machine. To be fair, the engine couldn’t be much lower as the close coupling of the Vee configuration means the two cylinders are angled up sharply resulting in a very tall engine. Whereas other V-twin designs use side by side con rods running on either shared or separate con rods, the Harley engine uses a con rod that runs inside a larger rod so both share the same bearing area and this creates a very narrow engine unit. This does have some disadvantages however as the two cylinders run inline greatly reducing any potential cooling effect.
The early “iron-head” engine is generally a tough unit but the gearbox can be considered to be a hand grenade with a loose pin. Not one for quick shifts, the gearbox has to be tolerated during this process or risk doing damage within. The take over by AMF, in 1973, is generally regarded as a down turn in quality but the same problems found during this period were also present after the return to HD ownership and were more a result of a dated engine design, unwilling to be over stressed, than anything else. From the factory the V-twin engines are built to tight and exacting specifications, requiring the run in period to be strictly adhered to, providing this has been followed the power plants are generally very reliable.
It is wrong to compare the Sportster with other machines with sport in the title, as it has a different angle on doing the same job. On the road a Harley is a good, practical, way to get around, very easy to ride and relaxing too. The engine never ever tries to goad you on to do stupid things, while the rest of the bike can be satisfying to get right, relaxed biking at its best.
Harley Davidson Sportster Model history
Often ridiculed by the larger engined, Harley owners, the Sportster actually did much to save the brand when it was introduced back in 1957. Before the XL series of machines Harley had tried a sportier model, The K series of 1954, using the side valve Vee twin power plant but this had reached its limits of performances and the K wasn’t a great success. A sportier version of the K, the KHK was introduced, with hot cams, polished ports. By this time, however, Harley-Davidson engineers had the basis of the new Sportster on drawing board.
In 1957, the XL engine was essentially a K converted to overhead valves and with a unit gearbox construction. This was the first Harley to give the British twins a run for their money, in a straight line at least, and further increases in power during the 60’s saw the 883cc machine maintain its lead in the performance stakes. In a time when the world had gone aluminium and exotic metals mad it comes as quite a surprise to find HD had completely resisted any temptation to join in. the Sportster engines top end remained the heavy and outdated lump cast iron it had been since 57. The basic Sportster sat in dealers showrooms awaiting the vast array of factory produced, after market parts to be bought and fitted, footrests, screens, an array of chrome and other such accessories.
The Sportster like many other HD models was often changed from year to year according to parts left over from old models or modified components coming through for future developments. This led to many rare and sought after, not to mention, complete contradictions of the specification and sales sheets. One thing that never did improve as the years rolled on was the performance, with every year, and new model, from the competition, the Sportster slowly lost its edge, becoming a contradiction of its name tag.
The first of several major changes happened in 1986 when the “Iron-Head” engine was replaced by the all-new, aluminium Evolution power plant which came in the traditional 883cc and a new 1100cc capacity. The racing engine, in a desperate attempt to keep up with screaming Honda fours and raving jap two strokes, had grown aluminium barrels and heads as early as 1973, the factory hadn’t seen fit to put these parts on the roadster until the total revamp of the engine now know as the Evo.
Five years later came a redesigned five-speed, non-exploding gearbox, and a year after that, the now ubiquitous belt-drive. A further increase in capacity to 1200cc was the last major update to the engine and many 883cc owners opt to put this top end on their machines.
Harley Davidson Sportster timeline
1947 – Minutes of a planning meeting tell of a bike in the design stage called the “Deluxe Sport Model,” the idea was to have a light weight machine coupled to a powerful engine.
1952 – The K model is introduced, a 750cc side-valve, V-Twin. It goes some way to creating a sportier Harley but isn’t good enough to make the world sit up and take notice.
1957 – The XL Sportster replaces the K model. This 883cc, overhead valve bike improves upon the power and handling of the K model. The engine and gearbox were of unit construction.
1958 – The XLCH is introduced. The CH is thought to stand for “California Hot,” and is a stripped-down version of the original XL. The new motorcycle also introduces the trademark “Peanut” gas tank and staggered dual exhaust.
1959 – Introduction of the XLH.
1967 – The XLH Sportster receives a 12-volt system and electric start.
1970 – The iconic XR750 racer is introduced, driven by what is essentially a short stroked Sportster engine.
1975 – New 35mm Showa forks, left hand side gear shifting is now the norm
1977 – The XLCR is introduced but is not a success
1979 – The XLS Roadster appears, a customized version of the traditional Sportster.
1982 – The 25th Anniversary Sportster
1983 – The XLX is introduced, a stripped down, customized Sportster.
1986 – The Sportster family receives the Evolution engine in 883 and 1100cc displacements.
1987 – The 30th Anniversary Sportster is introduced.
1988 – Introduction of the first of the Sportster Hugger. Motorcycles, which offered a lower seat height.
1996 – The first 1200S “Sport” and 1200C “Custom” bikes are introduced. The Sport offers race styling and power, and the Custom offers unique chrome appointments and other custom features unique to the bike.
1998 – Sportster production moves to Harley-Davidson’s factory in Kansas City, MO.
2002 – Patterned after the race model of the same name, the new Sportster 883 R pays homage to the racing success of the early 70’s
2003 – Harley-Davidson’s 2003 model year line-up included Sportsters with 100th Anniversary markings.
1979 Harley Davidson XLS1000 Sportster Specifications
- Engine – air-cooled ohv pushrod 45-degree V-twin
- Capacity – 998cc
- Bore/stroke – 81mm x 96.8mm
- Power – 68bhp @ 6200rpm
- Torque – 55 ft-lbs @ 3800 rpm
- Carburetion – 38mm Keihin
- Transmission – four-speed, wet clutch, chain final drive
- Frame – steel twin loop cradle
- Suspension – 35mm Showa telescopic forks. Twin shock rear
- Brakes – 2 x 250mm steel discs, Kelsey Hayes twin opposed piston calipers. 288mm steel disc Kelsey Hayes twin opposed piston caliper
- Wheels – 3.25 x 19 front, 4.00 x 18 rear
- Weight – 234 kgs
- Top speed – 120mph
- Wheelbase – 1500mm
- Fuel capacity – 9 litres
