BMW R100GS Bumble Bee

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BMW R100GS Bumble Bee
Manufacturer
BMW
Production 1988
Class Road
Engine
Four stroke, two cylinder horizontally opposed Boxer, 2 valves per cylinder
Compression ratio 8.5:1
Top Speed 181 km/h / 112 mph
Ignition Electronic ignition, Bosch
Transmission 5 Speed
Frame Double loop tubular frame with bolt on rear section
Suspension Front: Telescopic fork with hydraulic shock absorber.
Rear: Paralever adjustable preload, rebound damping compression
Brakes Front: Single ∅285mm disc, 2 piston caliper
Rear: ∅200 Drum
Front Tire 90/90-21
Rear Tire 130/80-17
Wheelbase 1514 mm / 59.6 in
Seat Height 850 mm / 33.5 in
Weight 210 kg / 462 lbs (wet)
Fuel Capacity 24 L / 6.3 US gal
Manuals Service Manual

The BMW R 100 GS Bumble Bee was a air-cooled, four-stroke, boxer twin cylinder, 2 valves per cylinder Road motorcycle produced by BMW in 1988. Max torque was 56.06 ft/lbs (76.0 Nm) @ 6500 RPM. Claimed horsepower was 59.94 HP (44.7 KW) @ 6500 RPM. It could reach a top speed of 181 km/h / 112 mph.

Engine[edit]

The engine was a Air cooled cooled Four stroke, two cylinder horizontally opposed Boxer, 2 valves per cylinder. The engine featured a 8.5:1 compression ratio.

Drive[edit]

Power was moderated via the Dry single plate, with diaphragm spring.

Chassis[edit]

It came with a 90/90-21 front tire and a 130/80-17 rear tire. Stopping was achieved via Single ∅285mm disc, 2 piston caliper in the front and a ∅200 Drum in the rear. The front suspension was a Telescopic fork with hydraulic shock absorber. while the rear was equipped with a Paralever adjustable preload, rebound damping compression. The R100GS Bumble Bee was fitted with a 24 L / 6.3 US gal fuel tank. The wheelbase was 1514 mm / 59.6 in long.

Photos[edit]

Review[edit]

The R100GS is one of the world's biggest and fastest off-road bikes. It is very good on the road but not so good on the dirt. The GS stands for Gelandestrasse or street scrambler. BMW call it 'a hobby bike, a two-wheeled Range Rover' and the comparison is appropriate. It is not a serious dirt bike but it is one of the best all-purpose bikes ever built. Suitably beefed-up factory versions have won the gruelling Paris to Dakar rally on three occasions. In stock production form, the 100GS has proved a popular choice for riders exploring the world on long distance trips across continents with all types of terrain. It is a 115mph road bike that can cope with the rough stuff. The machine is an imaginative mix of parts that were already available on other BMW bikes, spiced with some adventurous engineering. An example is BMW's patented Paralever rear suspension, a one sided swing-arm with a single gas shock unit. In effect, it is half a swing-arm, but BMW's engineers made it both lighter and 50 per cent stronger than a conventional assembly. The rear wheel is held on by three bolts, there is nothing you could call an axle. The wheel bearing is big, the crown wheel housing is internally stressed since it has to carry the full loads of the back wheel with 7in of travel available. The Paralever rear suspension works admirably, eliminating driveshaft torque reaction. Quick wheel changing is obviously a bonus.


The front suspension consists of leading axle forks offering a luxurious 8.8in of travel. The bike is tall and needs to be for reasonable ground clearance (8.58in). The steering is quick and the throttle response lively. The whole machine is light and nimble with plenty of power and very good brakes. Like all flat twin BMWs, it has a low centre of gravity, so the bike can be chucked around with abandon. The dual-purpose, knobbly tires are high-speed rated and tubeless thanks to an innovative cross-spoke wire wheel and isolated rim design. The engine is an updated variant of the R80 road bike endowed with typical BMW performance - bags of torque and a wide spread of power — plus some dual-purpose innovations. The bike has a lightweight clutch and flywheel for quicker throttle response, and low gearing; necessary for a dirt bike but lots of fun anywhere since it helps the GS to wheelie easily. On the open road it will hold 1 lOmph for as long as the rider can face sitting up so high and exposed against the wind. Unfortunately what makes it good on the tarmac tells against it on the dirt. The bike is just too big and too powerful. Fully gassed (5.7gal) it weighs 4541b, fine for a road bike but a little heavy for serious off-road use. In addition there is the long wheelbase, the unsprung weight of the driveshaft and two horizontal cylinders that stick out a long way, all factors that conspire against its dirt ability. These are not problems when traction is positive on firm ground but in mud and real rough stuff, the bike bogs down far too easily. The R100GS is best used as a cross-country bike, sticking mainly to proper roads but taking the odd short cut and back road where necessary. Above all else, the bike is a lot of fun to ride; it is a functional, practical, rugged and reliable all-rounder. Recently, various BMW importers have released Paris-Dakar replica versions of the bike as a tribute to one of the world's most successful desert racers.





Make Model BMW R 100GS Bubble Bee
Year 1988
Engine Type Four stroke, two cylinder horizontally opposed Boxer, 2 valves per cylinder
Displacement 980 cc / 59.8 cu in.
Bore X Stroke 94 x 70.6 mm
Cooling System Air cooled
Compression 8.5:1
Induction 2 x Bing carburetors
Ignition Electronic ignition, Bosch
Alternator Bosch 12V/280 W
Starting Electric
Max Power 44 kW / 60 hp @ 6500 rpm
Max Power Rear Tire 41.7 kW / 56 hp @ 6500 rpm
Max Torque 76 Nm / 7.75 kgf-m / 56 ft-lb @ 3750 rpm
Clutch Dry single plate, with diaphragm spring
Transmission 5 Speed
Gear Ratio 1st 4.40 / 2nd 2.86 / 3rd 2.07 / 4th 1.67 / 5th 1.50:1
Rear Wheel Ratio 1:3.09
Bevel / Crown Wheel 11/34 teeth
Final Drive Shaft
Frame Double loop tubular frame with bolt on rear section
Front Suspension Telescopic fork with hydraulic shock absorber.
Front Wheel Travel 225 mm / 8.8 in
Rear Suspension Paralever adjustable preload, rebound damping compression
Rear Wheel Travel 180 mm / 7.0 in
Front Brakes Single ∅285mm disc, 2 piston caliper
Rear Brakes ∅200 Drum
Front Wheel 1.85 - 21 MTH 2
Rear Wheel 2.50 - 17 MTH 2
Front Tire 90/90-21
Rear Tire 130/80-17
Dimensions Length 2290 mm / 90.1 in Width 1000 mm / 39.3 in Height 1165 mm / 45.8 in
Wheelbase 1514 mm / 59.6 in
Seat Height 850 mm / 33.5 in
Ground Clearance 200 mm / 7.9 in
Wet Weight 210 kg / 462 lbs
Fuel Capacity 24 L / 6.3 US gal
Top Speed 181 km/h / 112 mph
Road Test Adventure Group test Motosprint 1988