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BMW R 1100RS

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Make Model

BMW R 1100RS

Year

1993-94

Engine

Four stroke, two cylinder horizontally opposed Boxer, 4 valves per cylinder

Capacity

1085 cc / 66.2 cu in

Bore x Stroke 99 x 70.5 mm
Cooling System Air/Oil cooled
Compression Ratio 10.7:1
Lubrication Wet sump

Induction

Fuel injection

Ignition 

Electronic ignition MA 2.2 Bosch Motronic 

Alternator 12 V 700 W
Spark Plug Bosch, FR6 DDC
Starting Electric

Max Power

67.1 kW / 90 hp @ 7250 rpm

Max Power Rear Tyre

60.4 kW / 81 hp @ 6900 rpm

Max Torque

95 Nm / 9.7 kgf-m / 69 lb-ft.@ 5500 rpm

Clutch Dry, single plate

Transmission 

5 Speed

Final Drive Shaft
Gear Ratio 1st 4.16 / 2nd 2.91 / 3rd 2.13 / 4th 1.74 / 5th 1.45:1
Rear Wheel Ratio 1:2.81
Frame Steel, backbone frame

Front Suspension

Telelever with central spring strut & linear-rate coil spring. Twin-tube gas-filled shock

Front Wheel Travel 120 mm / 4.7 in

Rear Suspension

Paralever swingarm & shaft drive, single-tube gas-filled shock, variable rebound setting

Rear Wheel Travel 125 mm / 4.9 in

Front Brakes

2 x ∅305mm discs, 4 piston calipers

Rear Brakes

Single ∅276mm disc, 2 piston caliper

Front Tyre

120/70-17

Rear Tyre

160/60-18
Dimensions Length  2175 mm / 85.6 in
Width       920 mm / 36.2 in
Height    1286 mm / 50.6 in
Wheelbase 1485 mm / 58.5 in
Seat Height

780 mm / 30.7 in

Ground Clearance 153 mm / 6.2 in
Dry Weight 239 kg / 526 lbs

Wet Weight

268 kg / 590.8 lbs

Fuel Capacity 

22 Litres / US 5.8 gal

Consumption Average

6.0 L/100 km / 16.6 km/l / 39.0 US mpg

Braking 60 km/h- 0

13.5 m / 44.3 ft

Braking 100 km/h - 0

40.0 m / 131 ft

Standing ¼ Mile  

12.1 sec / 177.5 km/h / 110.3 mph

Top Speed

218.7 km/h / 135.9 mph

Road Test

Cycle World
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ONE OF the first things a racer does with a new bike is make it fit. Anyone trying a car for the first time fiddles with the seat. Hairdressers and jockeys spend time adjusting their apparatus before going to work. Everyone gets comfy, except motorcyclists.

We just sit there, being heroic and stopping every 100 miles for a fag or a walkabout. Admit it, your bike's a bloody torture chamber. Or we rejoice in the agony of crocked backs and wind-set necks and ringing ears, and masochisiti-cally revel in the sheer hell that is that seat. We adjust spring preload, ignition timing and Volvo drivers' wing mirrors, but we do not adjust motorcyles. We do pain.

Here at last is what Yamaha's outlandish Morpho future-concept has threatened, but what BMW, improving on a 70-year-old motorcycle, has actually put into showrooms: a bike with a tune-able riding position, on which the seat, screen and bars adjust more meaningfully than most suspension systems. The screen rakes through 20 degrees via a knob on the instrument pod. The bars swivel through three positions and 18 degrees and move forward or back through seven position and 40mm, the riders goes up and down three stages and 40mm.

I spent an hour dicing with an R1100RS alien key, and the bars emerged a fraction closer and at an angle narrower than the standard mid-setting (they are wide and TDM850-like). Raked back against the fairing the screen gives maximum ('sports') vision but, above 70mph, maximum wind-noise too; upright is quieter  a ('touring') motorway position - but distances you from the road. You can juggle bodyweight between pegs, seat, bars and tank; dominate the bike or relax into it. Turbulence-happy pillions looking for an easier life not only get a comfortable grabrail and the same heavily-rubbered footrests but a chance to experiment with their height relative to the rider's.

There's more, the RS bristles with innovation.

Telelever is a synthesis of telescopic fork and wishbone lever that effectively isolates steering from suspension from braking forces. Telelever teles, bereft of springs and damping oil, simply locate and steer the front wheel with minimised steering inertia; its independent wishbone operates an upright Showa shock; and most braking forces are passed horizontally through the wishbone into the engine's shell, dramatically reducing brake dive.

The RS junks the traditional boxer cradle frame, exploiting instead the monolithic engine's immense stiffness and low centre of gravity for not too much weight. Its stressed cast aluminium shell shifts forward - there's a 53 per cent front wheel bias — to provide conveniently low-slung fixing points for a steel-tube rear subframe (anchor point for the rear shock and seats) and a braced aluminium spar which carries the Telelever's top steering joint. The wishbone connects with the fork sliders via a spherical bearing on a brace above the mudguard, and pivots on the engine shell above the rear of the cylinders.

Given that conventionally forked boxers behave like long-travel pogosticks, Telelever is an elegant way of controlling the RS without blowing its quintessential BMW-ness. There's not a hint of flex -the elongated fork sliders are actually eliptical, bulging mid-section to resist bending, while the wishbone (designed to crumple in a smack) provides longitudinal stiffness — and the system's inherent anti-dive (and anti-rebound) allows a supple shock, able' to cosset the tourer and still track catseyes when the brake lever's against the bar.

Dive is reduced by about 60 per cent, and braking confidence leaps the same amount, especially as the floating discs and Brembo calipers are powerful K100 issue with 45kg less work to do. I ended up working towards extremely sporty stopping distances, tempted to hang on to the four-way adjustable lever right up until the ABS II cut in. This is BMW's second generation of anti-lock. It's more compact with a much refined pulsing effect at the lever but it isn't easy to read on the RS. In the dry it cuts in abruptly and conservatively early, just when the tenacious front Bridgestone BT50 radial is biting. On bumps it occasionally chimes in for no apparent reason (other than bumps), momentarily speeding the bike.

I think the radical RS's long and porky touring dimensions limit its stopping efficiency more than I realised. Telelever and all that Brembo kit make the RS feel like a taut, short-wheelbase ZXR on the brakes, but it isn't. It's just a good braker.

The RS IS naughty for a boxer. Its handling accuracy and stability in fast sweepers are only matched by a willingness to swing sweetly and virtually without vice along lazy B-roads. It rolls easily around its low c of g like a traditional boxer, but leans on through its footpegs to the rocker covers. Whereas the old ones can get slappy mid-turn if the throt-de's slammed shut, it only serves to stiffen the implaccable Telelever's resolve. There's certainly no hinge in this one.

As with the brakes, there are limits to all this sportiness. The previously excellent Paralever shaft-drive/mono-arm, now with a centrally mounted shock, suddenly feels five years out of date  sometimes wallowing in sweepers and chattering into bumpy turns when the brilliant front end is fully exploited. The 17-inch front wheel's long trail make the bike a bit sluggish to turn, particularly under power, but rubber-mounted bars, which move about an inch at the bar-ends, seriously dull the bike's steering response. Just when you need precision, the RS goes all floppy in your hands.

The new 90bhp four-valve boxer engine is hardly competitive with cheaper FireBlades and ZZ-RllOOs, but 135mph and an average 50mpg are figures most people could live with. Peak torque - 701b.ft is 50 whacking per cent up on the R100RS - is at 5500rpm but most is already in by 3000rpm. From 3000 to 6000rpm there's an even fatter plateau of smooth and cleanly delivered elasticity, now efficiently managed by Bosch Motronic microchips and fuel injection than Bing carburetors.

Nonetheless, the modern boxer feels much like an old one - it still pulls to the right on a blipped throttle, thrums and tappety-taps, and snatches down the driveline — but an old one cured of its legislated asthma and woolly throttle response. The move to a compact, high-cam, four-valve head has boosted torque across the rev range and you can hang out virtually anywhere on the tacho and still crush the traffic. Short pushrods and lighter pistons and conrods allow it to rev usefully to 7500rpm, and bounce uncomplainingly off its 8000rpm rev limiter.

BMW's bizarre switchgear has somehow survived the shake up. That's left bar — left winker and horn; right bar — right winker and cancel button. I've given up trying to learn them and go for everything. The sidestand that's too far away from the rider survives the revolution too, as do bar-mounted mirrors (good for field of vision) that are clear for only a few hundred rpm in the rev range. Conversely, the mainstand is wimp-friendly and the rest of the electrics, from the penetrative headlight to the mega-honk horn, ooze power and quality.

More old favourites: the gearbox is slow - no change there - and the wide-span clutch lever turns out to be about the only non-adjustable part of the motorcycle. The single plate clutch clunks, and shifts have to be pushed through deliberately, which is no different from the other boxers I've ridden. Most servicing (6000 miles) has to be done with diagnostic computers but access to the spark plugs and top end (as well as the rear shock's preload and rebound damping adjusters) is superb. The alloys clean up beautifully in 30 minutes (though a good winter is the only valid test of a BM's finish). Warm air still pours off the cylinders onto feet and shins while the forward mounted engine and fuel injection have cleared the clutter from around the footpegs. The tookit's lovely, the puncture-repair kit's reassuring and the maps are very educational. So no change there, either.

The difference is this boxer cost BMW £60 million so it'll cost you a lot too  £8485 for the basic model. Heated grips (heaven on a motorcycle), the clock/fuel gauge/oil temperature gauge/gear indicator panel (which we didn't have), panniers, and three-way catalytic converter are all extras. The fully faired (SE) model takes the price to £8995.

That's wads of cash and philosophically a million miles from utilitarian boxers of old. But there's no doubt in my mind that this is the finest BMW to leave Germany. It has beaten the Eurocrats, the environmentalists, and broken all sorts of technical ground in the process. All it's got to do now is convince the BMW cognoscenti. That could take longer.

Source  Bike Magazine 1993