BMW R80/7

BMW R80/7 Road Test




BMW R80/7During the late seventies, BMW bikes were much scorned among the majority of the biking fraternity. Antiquated looking designs and heavy machines sent all of the wrong signals to those who had yet to sample the real delights of riding a Beemer. Even those that had actually tried one would have instantly fallen foul of the sloppy, clunking gear change, soft chassis and lazy power delivery when metered alongside the current crop of oriental designs. It takes far more than a short hop around the block to grasp the potential of a BMW.

The fascination with horse power, and sweeping looks that the Japanese manufacturers placed so much faith in, and still do, was not embodied in any way by the BMW designers, preferring instead to make well engineered, fine handling, yet simple and agile machines. In these respects the German concern has always trod it own path both mechanically and aesthetically, sometimes the have influenced the rest of the world other times not, either way it hasn’t really affected their way of thinking and the way they build motorcycles.

The threat from the oriental bike makers nearly caused the BMW heads to cease production as the engine capacities increased along with the complexities and the build quality while prices remained comparatively low, leaving the Germans somewhat left behind. It was only a decision to revamp the aged product range in the late sixties that saw the emergence of the modern day Boxer design, fortunately raising the profile of the biking side of the company and saving the day for the breed both then and in the foreseeable future.

BMW R80The decision to remain in the two-wheeled market place, and also stay true to the designs roots, has since proved a prudent one with high-class products and a customer satisfaction rate second to none. In reality the Boxer engine, with roots that can be traced back to the M33A power plant of 1923, encompassed so many of the ideals the Japanese later searched for, like minimising internal friction losses and keeping balance dynamically. Further more, with the complete power train running in one straight line until the very end part at least, the losses that we usually see in a more conventional engine layout, around 15% between the crank output and the rear wheel, are kept to an absolute minimum. The shaft drive unit does still absorb a fair whack of the precious few horses the twin engine puts out but it is a generally efficient and superbly robust unit. In fact it was so good that Yamaha had no choice but to license the use of it, albeit upside down and on the opposite side, for the early XS range and has continued to do so for the XV and many other designs since.

In reality the Beemer was perhaps the first machine to be built around the whole picture with the engine and chassis perfectly complementing each other, typically German in ergonomics and design, nothing appears to have been compromised or spared in the pursuit of the end result.

Power never gets hurried with a Boxer engined BM but it is always strong, torquey and more importantly readily on tap, as if the two pistons are constantly trying to slug it out and out do each other in a battle that can never be won until something actually fails.

R80/7If you need further evidence of what a Beemer twin can do in the right hands look at Helmut Dahne’s staggering TT efforts on little more than a modified and lightened R series machine

He was using the rocker box covers as lean indicators years before knee sliders had been thought of and yes he did go though a few in the process. In fact the Boxer saw active service on the racetracks of the world, in the US the type was extremely heavily developed by various BMW dealerships and often threatened the Jap multi’s in production based races. It was the legendary battles between R90 mounted Steve McLaughlin and Reg Pridmore as they fought for the US national championship back in 1976, which actually spawned the current World Superbike series that we know today. On the continent too, Beemer’s saw service in many road-based formulas and also endurance racing where the shaft drive came into its own enabling easy wheel and tyre changes with the added bonus of no adjustment being necessary.

Despite the poor press and public perception of the time the R series is more than capable of traversing huge distances at immense speeds, all CMM readers will admire the FJ1100 and 12 for this aspect but the BMW’s were doing it way before then. Finely designed, well balanced and a strong chassis combine with competent suspension components to give a supply yet staggeringly effective ride. The wide torque range means the engine simply plods along with devastating results allowing the rider to concentrate on other matters, that’s why the police used the R series almost exclusively during the period, and some of those boys could really ride them.

BMW R80/7Recently talk at CMM, and its sister publication UBG, has centred on classic machines that could feasibly be expected to handle serious distance’s while still being affordable, reliable and practical. There can be no doubt that the Beemer sits firmly at the head of this category with little in the way of mechanical foibles and a serious mile munching ability. Every part and consumable is still easily available throughout the UK and Europe making the Beemer an almost ideal travelling companion no matter what the distances involved.

Being around an R80/7 for the first time they do feel bulky at a stand still and this is not helped once the engine is started, the whole plot lurches to one side with every blip of the throttle due to the significant engine torque, this is an experienced you don’t normally feel with a transverse engined machine as the forces are travelling in a direction that is absorbed both by the suspension and length of the chassis. With a Beemer the opposite reaction to the turning of the crank and internal components spins the bike between your legs and at its worst could cause you to loose balance particularly on the larger capacity R90 and 100. This can also be felt on that other great opposing engined icon the Guzzi but it is at its strongest with the German machine.

BMW R80That aside, it’s into gear and once on the move another disconcerting occurrence catches the first time BMW rider unawares, the huge clunk that accompanies gear change. Like a car engine the single plate clutch spins at the same speed as the crankshaft making the smoothest of shifts a difficult process to get right. Of course the mechanically sympathetic amongst you will quickly learn to match the engine speed with the road speed for ultra smooth shifting but I would imagine for some people this could prove a troublesome thing to get the hang of and no doubt the cause of many riders initial dislike of the twin pot Boxer engine. After a few minutes on the R80 I was changing without the clutch on up shifts and the mechanism was smooth and relatively Clunk free although still nothing like as slick as any of the Jap engines.

Manoeuvring the big twin at speed is a pleasure not often found in 70’s Superbikes, with no bad manners at all being demonstrated even when the speed lifted up into treble figures. Braking hard, via a cable to the master cylinder tucked well out of harms way, causes no chassis upset and once tipping over in readiness for a corner the compliant touring based suspension tightens up to give a very re assuring feel and ride.

It soon became apparent that the R80 liked to be considerately set up for corners rather than just dropped in but all that meant was a little forward thinking on the entry to a bend, once in to a turn the line could be swapped and changed at will, you just need to get the suspension tightened from its upright relaxed phase, into the stiffer mode.

BMW R80/7This handling excellence is surprising especially when one notices the possible frailty of such items like the wafer thin steel top yolk, evidence that the forces involved have been carefully and precisely worked out and factored in to the design. If there is one aspect of machine design that the Germans have given us it is, thankfully, fine road holding.

Unlike the similar Yamaha unit which severely lifts the rear under acceleration and drops it on the shut off, the shaft drive does its duty without drawing unnecessary attention to itself and the feel is little different to a good quality chain and sprocket set up only without the mess and need for adjustment. A Beemer can really lean too, the low centre of gravity enables extreme angles to be achieved and, like good old Helmut Dahne, it wouldn’t take much to get the rocker covers down despite the spindly tyres.

Another unusual characteristic of such a large and potentially bulky machine is the low speed handling which is almost trials bike like, with a vast amount of steering movement allowing an unprecedented single stab at turning around on the narrowest of roads. The engine is slung low down enabling a feet up approach to traffic and give way junctions, in fact the BM will sit, feet up, quite motionless and stable for some time. All of the major reciprocating components within the engine, like the crankshaft, camshaft and clutch, share a central position, as do heavy items like starter motors and alternators, making the potentially unwieldy and heavy power plant a delight to shift around when on the move.

BMW R80 specifications

  • Engine; 797.5 cc air-cooled four-stroke horizontally opposed twin-cylinder OHV
  • Bore x Stroke; 84.8 x 70.6 mm
  • Max Power; 55 hp @ 7,000 rpm
  • Max Torque; 47 ft lb at 5,500 rpm
  • Carburation; 32mm Bing CV carburettors
  • Gearbox; 5 speed constant mesh
  • Clutch; Dry single plate, with diaphragm spring
  • Ignition System; Contact breaker
  • Chassis; Double loop steel tubular frame with bolt on rear section
  • Front suspension; Telescopic fork oil damped 200mm travel
  • Rear suspension; swinging arm with adjustable struts 125 mm travel
  • Tyres; Front 3.25 H 19
  • Tyres; Rear 4.00 H 18
  • Brakes; 260 mm discs single piston floating calipers, 200mm single-leading-shoe drum
  • Wheel Base; 1465 mm
  • Fuel tank; 24 litres
  • Weight; 215 Kg
  • Top Speed; 111 mph

BMW R80/7 Gallery

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