BMW Motorrad Anniversary: 30 Years of GS
Wednesday, April 7th, 2010“Can boxers fly?”
The answer to this question was to be found in the sporting arena. In 1978 the German motor sport authorities introduced an over-750 cc class of off-road competition for the first time. Backed by the head of motorcycle testing, Peres – an experienced off-road rider – teamed up with two employees to create a registration-approved off-road machine powered by an 800 cc boxer engine and weighing just 124 kg. Peres rode the machine to the runners-up spot in the German championship, showcasing BMW‟s off-road potential. The brand went one better the following year, claiming the championship title in the large-capacity class with rider Richard Schalber. The BMW factory team delivered another show of strength in the International Six Days Trial in Siegerland, West Germany, in 1979; Fritz Witzel Junior and Rolf Witthöft won a brace of gold medals in a competition attracting significant public interest. The Six Days Trial was very much the Olympics of off-road motorcycling at the time, a gold medal reflecting elite performance in terms of both riding ability and bike technology. BMW had made the breakthrough.
The valuable knowledge the brand built up through its highly publicised involvement in sporting competition was channelled into the development of the new enduro. It wasn‟t only the endeavours of the competing machines that was so valuable here; the experience gained with the support bikes – based on the R 80/7 – also played an important role. These motorcycles had to be able to follow the competition machines wherever they went and yet remain as close as possible to a series production blueprint.
2. Serial winners.
Plotting a route from sport to series production: the R 80 G/S.
The BMW testing department condensed all this knowledge into the new bike presented to the international press in Avignon, France on 1 September 1980. The concept of a touring motorcycle with off-road ability was a new phenomenon in the global motorcycle industry, as was single-sided suspension on a large-capacity machine. Together, they caused a genuine sensation. Sceptics had wondered aloud how an 800 cc model with cardan shaft drive and weighing 200 kg could be even vaguely suited to off-road riding, but a press event for the new machine left the attendant journalists vociferous in their praise. “The best road motorcycle BMW has ever built,” summed up German biking magazine Motorrad. On the road the 800 cc model producing 50 hp ticked every box, while off the beaten track it proved more usable than the prophets of doom had predicted. The critics who, ahead of the presentation, had dismissed the new BMW as a poor compromise quickly fell silent as the new arrival proceeded to establish a whole new class of motorcycle.
BMW promoted the versatility of the R 80 G/S with the words “Sports machine, touring machine, enduro… Welcome to a motorcycle concept with more than one string to its bow.”
This summed up the appeal of what was a stylistically fresh and innovative machine with unrivalled all-round capability. With no dramatic loss of ride comfort or on-road performance, BMW had created a motorcycle which could easily hold its own on any kind of road – or mountain track. Its scope of usage comfortably surpassed that of any other all-rounder that had gone before, and was complemented by both the ease of maintenance that had become typical of the BMW brand and an image that exuded reliability.
The R 80 G/S weighed some 30 kilograms less than the R 80/7 road model. This weight saving promised to be a recipe for stand-out handling characteristics, and lent the machine a visual lightness.
Cutting-edge technology with a timeless style.
However, it was the single-sided swing arm – hotly debated among BMW fans and beyond – that remained the most talked-about feature of the new machine. Christened the “Monolever”, this suspension system had no swing arm or spring strut on the left-hand side, as the concept did not feature an axle as such. The wheel hub was fixed to the crown wheel housing of the rear drive with three bolts, like on a car. Whichever way you looked at it, this was a step forward. This configuration was two kilos lighter than a conventional solution, and the swing arm had greater torsional rigidity, was cheaper to manufacture and made maintenance and repairs that much easier. Plus, there was nothing on the left-hand side of the bike to obstruct the compact installation of the two-into-one exhaust system.
Aside from the pivot point of the spring strut on the upper right loop, some small brackets and the positioning of the footrests, the frame was identical to the main frame of the R 45 and R 65 models. The proven OHV engine had been revised well beyond the scope of its scheduled update, setting it up for another decade and more of service.
Strengthened engine housing with improved lubrication guaranteed greater thermal stability and a longer service life. The sump, meanwhile, was protected by a perforated plate. Elsewhere, the more lightweight cylinders with coated contact surfaces sliced 3.4 kg off the bike‟s weight, while the new, 40 per cent lighter clutch on the G/S saved a remarkable 4.7 kg. This clutch, which also served as a flywheel, enhanced the smoothness of the 5-speed transmission and increased the engine‟s agility. Also making its debut on a BMW was the maintenance-free, contact-free electronic ignition system from Bosch, which likewise saved weight and occupied less space with its twin ignition coil. Plus, the new low-profile air filter allowed easier assembly and reduced intake noise. All the modifications helped to ensure that the G/S engine was lighter, more agile and durable than its predecessors.
The clearly arranged central electrics were also sourced from the R 45 and R 65. The twin ignition coil and all relays were located under a 19.5-litre fuel tank – with familiar enduro screw cap – which had been specially designed for the G/S.
The fork and brake disc were taken from the R 100/7. Never before had there been an enduro bike with a disc brake. And never before had an enduro reached 168 km/h in type approval testing, the engine drumming up 50 hp from its 798 cc displacement at 6,500 rpm.
New plastic parts, such as the cover for the H-4 headlamp (used for the first time on an enduro bike), the front fender fixed to the lower fork bridge, the side cover, the seat bench with lightweight and corrosion-resistant plastic base and the functionally designed rear fender, rounded off the lithe appearance of the R 80 G/S.
Up to that point, motorcycles equipped for off-road use were not up to speeds of more than 140 km/h and never weighed more than 150 kg. The G/S also broke new ground when it came to its tyres; their off-road tread now had to withstand a top speed of 180 km/h. With this wide range of modifications, the R 80 G/S represented the most fundamental revision yet of the BMW motorcycle technology introduced in 1969.
