BMW GS 40 years on
THE BIKE THAT SAVED BMW
On 1st September, 1980, BMW nervously prepared to lift the covers from the motorcycle on which the company’s very future hung. Assembled in Avignon, France, members of the European motorcycle media shuffled impatiently as the pre-amble unfolded. What greeted them was unlike any previous BMW; at least any production BMW. For what was officially termed the R80 G/S (G standing for Gelände ‘terrain’ and S for Strasse ‘road’) had in fact been around for quite a while, unofficially of course.
BMW at this point was staring at the very real possibility of abandoning motorcycle production. The division was unprofitable, and although the models were of unquestionably high quality, they were staid in comparison to many of their rivals and demand was on the decline.
Decades earlier, specially prepared BMW flat twins had been successful in major competitions such as the International Six Days Trials, but more recently had claimed a series of European Enduro titles from 1970 in the hands of Herbert Schek on a heavily modified R75/5. The BMW factory officially got into the act in 1979 with a full team effort that netted the German Cross Country Championship, using the R80 as the basis. Typically, the factory bikes were built at considerable expense, and although some of the wealthier enduro types expressed a desire to buy one, that didn’t happen.
At the time, there was something of a revolution brewing as the old concept of ‘street scramblers’ – basically road bikes with a few bits like high pipes and lighter mudguards bolted on – gave way to models that adhered more rigidly to the dual-purpose mantra. In other words, motorcycles that could literally go anywhere, but still operate satisfactorily on the street. Of course, the early attempts from European and Japanese manufacturers tended to be small
capacity, single cylinder, and often two stroke. What BMW had in mind was something larger – much larger.
That day in Avignon concluded with the assembled media being let loose on the new machine around the back streets before the bikes were rounded up, and carefully detailed for their public bow at the IFMA Show in Cologne which opened on 19th September. In the 18 days previous, the press reports began filtering out, and by the time the doors were flung open in Cologne, G/S was the word on everyone’s lips. For a company as conservative as BMW, the new machine was as radical as it got, even down to the colour scheme; vivid white with a vermilion seat and blue flashes on the tank.
Who came first?
While there is considerable evidence of off-road flat twins from BMW preceding the launch of the R80 G/S in 1980, down in Melbourne one was constructed well prior to that. Champion sidecar rider and constructor Lindsay
Urquhart was with BMW at the time, and had visited the factory in Germany as part of his role as Service Manager for the Australian operation. “I met Herbert Schek while I was there,” says Lindsay. “He was a huge bloke, about six foot seven – and that was across the shoulders! Anyway a bit later I decided to build a play bike for myself and started with an R90S
engine into which I put the crankshaft and rods from the R65 with shorter barrels, so it was quite narrow with a capacity of around 800cc. I made the frame – virtually a copy of Maico geometry with a splayed tube arrangement and the good Marzocchi forks with magnesium sliders. It had a Suzuki DR tank and seat and it worked out pretty well.
Around this time the BMW Service manager came out from Germany and saw the bike and he was quite impressed. He asked if he could send it back to the factory so they could have a look at it so off it went to Germany.
As an aside to that, I went to Darwin with the German Service Manager and took him out to some cattle stations so he could see the conditions. The farmers there used to buy old BMWs and strip them to use for herding cattle. They loved them because when you had to stop quickly to grab a steer, they would just drop the bike on one of the cylinder heads! My ‘play bike’ did eventually come back from Germany to Melbourne and my son raced it in a desert race in Mildura, but it would destroy the rear tyre after an hour’s running. Eventually I sold it – I wish I hadn’t – and I believe it is still somewhere in New South Wales. If anyone knows where it is,
I’d be keen to buy it back!”
Come and get it
The IFMA Show well and truly lit the fuse for the
G/S concept. Dealers clamoured for stock to flog to an eager public. Even the rather astronomical price – $5000 in Australia – failed to deter. And despite the fact that it was an 800cc twin, the GS weighed it at just 167kg – the same as a Honda CB250N, or 8kg less than the Suzuki GS450E. With the puny 19.5 litre fuel tank full, the ride-away weight rose to 186kg. Saddle height was a slight issue; at 835mm tiptoes were required for many, but with such a low centre of gravity that didn’t seem an insurmountable problem. The new machine was no powerhouse, with 28.0kW at 6,500 rpm at the rear wheel, and 42.3 Nm of torque at 6,000 rpm. Engine-wise, BMW had started with the stock 800cc R80 engine, lightened the flywheel and clutch and slightly raised the compression ratio to 8.2:1. Weight-saving alloy barrels with the curious Gainikal coating process, a battery-powered electronic
ignition system, electrical starting, conventional Bing carburettors, and a two-into-one exhaust system (with the muffler on the left side) are worthy of note. The company’s trademark cardan shaft drive had also been subtly refined for the new model, attached to which was the single rear shock absorber. The transmission itself incorporated a new single plate clutch.
In the chassis department, BMW began with the R65 unit and removed every piece of metal deemed not vital, including the left side of the swinging arm which alone saved two kilograms. BMW also claimed that the redesigned shaft housing gave greater torsional rigidity for the same weight, and of course made rear wheel removal extremely simple – something that would be appreciated out in the bush. Up front sat leading axle forks with progressively wound springs, offering 200mm of travel. A light, small (264mm) diameter front disc did an admirable job of stopping, coupled with the 200mm rear drum.
Moving right along
BMW’s gamble on embarking upon the G/S was instantly rewarded. The new model captured 20% of the company’s sales. Projected sales almost doubled in the first two years of production; by Christmas 1981 6,631 had been sold and back orders were piling up. That figure had risen to 21,864 by the time the range expanded to two models with the release of the R 100 GS (note the dropping of the oblique slash) and the new R 80 GS with Paralever rear suspension in 1987.
This rear suspension change was much more than a marketing gimmick. What BMW termed ‘Paralever’ was in fact a modern version of the patented system first used on the works 500cc Rennsport racer, with double joint and driving force support. Although it was used for racing, cost consideration meant it had thus far not found its way onto the road range. In this system, the housing for the drive to the rear wheel was positioned on the suspension arm, with two roller bearings in the arm and an extra universal joint in the drive shaft. The single shock absorber could be set in four positions and travel increased to 180mm with a progressive action.
Front suspension was improved by the adoption of a new telescopic fork made by Marzocchi; a system developed in the highly successful Paris-Dakar team that netted BMW four wins from 1981. Tubeless
tyres were another innovation, running on new rims where the spokes ran through the flanges rather than the centres, meaning that individual spokes could be replaced without removing the tyre. Finally, the fuel capacity, long the subject of complaint from long distance off-road riders, was increased to 26 litres. A more comfortable saddle was also welcomed, while the new 1000cc GS sported a standard windshield, which was an option on the smaller model.
Like all manufacturers, BMW was working hard on meeting ever more stringent emission requirements, and the end of the road for the air-cooled two-valve engine was clearly on the horizon. In September 1993, the latest incarnation of the GS appeared at the Frankfurt Show, sporting the fuel injected fourvalve cylinder heads and air/oil cooling that had first been seen on the R 1100 RS the previous year. The new R 1100 GS featured a completely new chassis derived from the R 1100 RS with the engine/gearbox as a fully stressed unit. While the rear suspension was an improved version of the proven Paralever system, bolted to the motor via a tubular sub-frame, the front was completely new. This BMW labelled Telelever, also developed on the RS – a hybrid system that combined a telescopic fork carried on a single lower wishbone and upper and lower ball-joints with built-in anti-dive. Suspension movement at the front was now a generous
200mm, with 190mm at the rear of the single sided swinging arm which had the shaft running inside it.
Basically, a parallelogram, the rear end had a torque arm running below the swing arm back to the frame and with two universal joints in the driveshaft, eliminated the usual lifting of the frame of conventional shaft drives, mimicking chain drives.
Braking was also uprated with the adoption of the twin 305mm discs with 4-piston callipers taken from the four-cylinder K series, with a single 276mm disc brake replacing the old drum at the rear. ABS was available as an option, and this could be disconnected for off-road riding.
Within twelve months, the 1100cc engine grew to 1150 and was used on the R, RS and RT as well as the GS models. Still pushrod operated from highmounted camshafts, the engine design produced precious extra ground clearance as well as improved performance. That performance grew further in
2004 with the introduction of the R 1200 GS, which was far from being merely an upgrade of the 1150. Although the engine gained a balance shaft to counter the vibrations from the ever-increasing capacity, the new 1200 weighed in a massive 30kg under the old model. Notable in the chassis set up was the transfer of the rear suspension linkage moved from below the swinging arm to above it. The electrics also came in for a revolutionary upgrade, with the traditional wiring loom largely replaced by a circuit connecting all control units and power-consuming components. This system dispensed with fuses and relays, apart from the starter motor, and featured built-in diagnostics.
The GS was the first model in the BMW range to be fitted with the upgrades.
This configuration stood the GS (and the other big twins in the range) in good stead for six years, until in 2010 the pushrod valve operation finally gave way to twin camshafts mounted in the cylinder heads. Three years later, water cooling arrived, along with other major changes. The drive shaft was now on the left, with the muffler on the right. The clutch, perennially located at the rear of the engine, was now at the front.
With detail changes, this model continues to the present day, albeit upped in capacity yet again in 2019 to 1250cc, with what the company called the ShiftCam engine – variable valve timing in other words. In the so-far 40-year history of the GS, the model designation has expanded to include variations of the theme, including parallel twins and singles, but it will forever be associated with the trademark flat twin. It all goes to show that a group of individuals in the ‘seventies, spread across the planet, all had a similar idea that involved taking the same engine configuration and using it to conceive a motorcycle that has literally changed the face of motorcycling.