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R90S: Supple, Fast, Handsome, Comfortable, Quiet and Expensive
“Breath-takingly priced, but also lavishly endowed with quality and the kind of performance that makes you wonder why everyone has to travel so slow.
“As somebody once said, the law is a crude instrument. Here we are, obliged
by inelastic law to travel at speeds no greater than 55 mph, and that is presumed to be without exception the right and moral thing to do. Lowered highway speeds, we are told, bring about a critically important reduction in the average American automobile's fuel consumption-if only down from the obscene to
being merely grotesque. We also are told that this originally-economic legal stricture now has moral force because our traffic safety record is not quite so dismal at the lower limit, and that may even be
true. Vehicles with a demonstrable reluctance to stop or turn collide with less frequency, or at least with less force, when driven at 55 than they did when streaking the Interstate highways at speeds up to 80 mph.
“
But then something will come along to demonstrate that Churchill had it right
when he commented that 'the law is an ass.' For us, that demonstration is the
new BMW R90S, which isn't decently in stride unless it's moving fast enough to
give a highway patrolman apoplexy. And none of the rationalizations offered up by
all the law makers and enforcers will keep the BMW from making the law itself look
arbitrary and silly. They want to argue about energy conservation? The BMW
can't be hammered hard enough to make it eat gasoline at a rate much worse than
45 mpg. Safety? Nothing capable of motion is entirely safe, but if they want to
talk about one area in which safety-related vehicular performance can be quantified there is the fact that the
BMW R90S can be made to stop at the rate of 0.9G, while the average passenger
car will be straining a brake hose to get 0.6G. Thus, the BMW actually is less likely
to become a participant at the scene of an accident when whistling along at 80
mph than is the typical sedan moving at a sedate, lawful 55 mph.
“
Don't bother relating any of the above to the police or the courts; their first allegiance is to law, not reality. The law assumes that there is absolute equality among passenger vehicles, and conversation about fuel consumption rates and stopping distances will avail you naught. Acknowledged or not, the reality is that
the new BMW R90S is comfortably, inspiringly unequal to most other road-going vehicles. Unequal, and unlike evenits fellows in the world of motorcycles. Other bikes have twin-cylinder engines,
the opposed-piston configuration isn't unique, nor the twin-disc front brake, nor
shaft drive, and the offset-axle fork design has been around for years. But BMW's
technological shopping list always has been peculiarly its own, and today's 90S
is a motorcycle of strongly individual character, with a usefulness that extends
well beyond the essentially futile gesture of making the law look silly.
“No small part of the BMW's usefulness stems from the fact that it is a comfortable
fit for its rider. One of the things you don't see, looking at the standard side-view
photo of an R90S, is that the bike really is very narrow. Sure, the cylinders jut out
like finned fire plugs, but you don't have to straddle them with your knees. All you
have between your legs and feet is a tall, narrow fuel tank and an equally tall, narrow engine/transmission casing. There's only 12 inches separating the footpeg rubbers, which is about five inches closer
than the same between-pegs gap on a Kawasaki Z-1. The BMW's fuel tank holds
6.3 gallons -a half-gallon of that being reserve - but the capacity is obtained with
height and length, not width.
“There's only one rider-contact area on the R90S wider than the average for motorcycles and that's the seat, which is a boon to tender backsides. BMW has made
the R90S seat a bit thinner than those on its other models, and used a more
dense foam for padding. And the differences seem to zero out, because the
R90S impressed us as offering a rider perch every bit as comfortable as the
soft-saddle R90/6-which is better than just about anything. Passengers will notice some difference, as there's a fender-clearance groove in the rear of the seat pan that thins the padding at that point.
Owners of earlier BMWs should take notice of the lateral-pattern ribbing on the
seat surface, which has been introduced in response to complaints that the old
smooth-top seats didn't offer enough grip to keep R90S riders from slipping back
toward the passenger grab-rail under full-throttle acceleration. This, despite the
step in elevation between the rider's and passenger's portions of the seat.
“Ride an R90S and you'll appreciate how one could become a backslider, both
literally and with respect to speed limits. The engine may have only those two
cylinders, but they're biggies, fed from a pair of 38mm Dellorto 'pumper' carburetors, and working with about as much compression (9.5:1) as a 90mm-bore engine dare have in a world with fuels not
always equal to their octane promise. We don't know how much horsepower the
R90S engine makes. Bikes with chain driven rear wheels we test on Webco's
dynamometer, but the shaft drivers would require special and very expensive couplings. It probably doesn't matter much with regard to the BMW: the drag strip figures say there's a goodly amount of
sheer horsepower available, especially as compared with the bike's weight; more
important to the realities of highway travel is the kind of urge the engine develops.
The BMW's power simply is always there. You don't have to downshift two gears
before the bike will respond to a big handful of throttle. Kawasaki's Z-1 will do
the R90S right in the eye at the drag strip, but the BMW pulls smartly away from the
Z-1 in a top-gear 60 mph roll-on. It cranks up a lot of power without having to be
spinning lots of revs. Open the throttle, and the R90S moves out in a flurry of
emphatic, closely-spaced thuds.
“Those thuds can be used to embarrass
other Superbike riders they also can be
a source of irritation for the R90S rider.
They are very substantial 449cc thuds.
and they react into the surrounding metal
to produce a strong lateral vibration when
the engine is at full throttle, and full thud.
This vibration may be minimized by closing the gap between thuds, done by using
lots of revs, which gets converted by the
BMW's tall overall gearing into speeds
that will blow transistors in every police
radar unit within a hundred miles. The
R90S will do those speeds safely, economically and without seriously taxing its
engine or rider, and the bike must be an
absolute wonder in the laissez-faire atmosphere of autobahn touring in its native
land. You can't get away with that sort
of mach-number cruising here, except in
short, furtive spurts, but it's kind of exciting /intriguing /frustrating (choose one) to know you're on a machine capable of making mincemeat of the usual time-distance equations.
“There is, on a more mundane level,
another way of getting the BMW R90S
to justify its reputation for smoothness.
You simply click the transmission into 5th
and roll with traffic. At a fudge-factored
60 mph, which is in most areas enough
to make the highway patrol's eyes narrow
but not provoke action, the BMW needs
so little throttle to maintain the pace that
its thudding weakens almost to the level
of imperceptibility. Cruising like that the
engine is virtually idling, far more likely
to expire of boredom than mechanical
stress. If there's a compensating factor
for the rider, it is that he is at least being
bored comfortably and can devote full
attention to such scenery as may be
available without distractions from a
jouncing ride or bed-of-nails saddle.
“If there's anything the BMW doesn't do
it's jounce The front fork has ultra-soft
springs, a 200mm (7.9-inch) travel, and
a miniscule amount of static friction, so
the front wheel willingly moves to accommodate pavement ripples that would get
transmitted straight into the handlebar of
any other bike. BMW's offset-axle fork
design has a number of advantages,
among them is that fore/aft loads are
carried over a greater length of fork slider;
also that the slider can be bored straight
through, instead of being a blind hole, and
its actual internal diameter machined to
more precise tolerances.
“There's an unusual degree of precision
in the rear suspension, too, along with
a pair of shocks that provide a 125mm
(4.9-inch) travel. The swing arm pivots on
tapered-roller bearings, and rear wheel
alignment is built-in because the shaft-driven axle doesn't have to slide to allow
for chain tension adjustments. So the
BMW gives you soft springing, more wheel
travel at both of its ends than anything
this side of a new-generation motocrosser, and wheels so precisely aligned
that you can tighten the throttle set-screw,
lean back and ride for miles without
touching the handlebar grips.
“Compliance-oriented suspensions and
shaft-driven rear wheels have distinct advantages; they also bring with them a
couple of penalties. BMW's engineers
have integrated the R90S rear hub elements - brake drum, shoes, bevel gears,
etc. - into a fairly light assembly, but it still
is heavier than its chain-drive counterpart. There are times, as when going
quickly over choppy road surfaces, when
the BMW's unsprung rear wheel masses
get to be a bit more than its springs and
shocks can control. And when going
quickly you also discover that really hard
braking loads the front suspension almost
to the compression stops, and that the
R90S then acquires a very steep steering-head angle - a hair too steep for steadiness if you're banking into a turn at the same time.
“Right here would seem to be the appropriate point to deal with the R90S's handling, which is apt to be the subject of some highly personal judgments. The
whole matter can be resolved if everyone
understands that the BMW is a sport
model, not a racing machine, made for
the sporting rider, not racers. It's a question of riding style: racers, especially
those of the modern school, sail into
corners with brakes applied hard and will
use a lot of brake all the way to a turn's
apex; the sporting rider tends to do his
braking upright, then flop the bike down
into whatever attitude conditions require
and proceed around under steady throttle
until he can see straight road. Assuming
approximately equal levels of enthusiasm
and skill, there isn't as much difference
between the two styles' here-to-there effectiveness as you might suppose. Not
unless you're riding an R90S, which is - heart and soul - prepared to give the
sporting rider all the cooperation he could
ask, but gets all sulky and confused by
the racer's overlapping demands.
“It is right and proper that the R90S
should be suited to the sports rider rather
than racers. The latter, with rare exceptions, never have much money left after
offering up their bank accounts as sacrifice to their art, and the BMW's price
places it exclusively among the fat-wallet
crowd, which is far larger than we had
imagined. Our first report on the R90S
wondered 'if the day of the $3000 motorcycle is here.' BMW's subsequent sales
figures proved that the day had indeed arrived and more recent history, which
has brought further price increases, is
evidence that there are more motorcyclists among the megabucks bunch than
we thought, and that they'll pay whatever
is asked for what they want if they think
the package justifies the price. BMW's
R90S is highly priced . . . and fairly well
justified in terms of features and craftsmanship.
“One look at the BMW and you know
it has quality. There is that almost indefinable something we'll call tidiness, and
wherever you look pieces fit and sparkle.
You get items like the twin brake discs,
which have been perforated (a hundred
holes in each) to make them lighter and
more effective in a streaming rain. Look
closely and you'll see that the discs have
been cadmium-plated before being surface-ground; BMW doesn't want unsightly
rust inside those punched holes. And
since the first R90S was introduced the
caliper and master-cylinder piston diameters have been increased, because that
change improves the brakes' feel. The
BMW front brake always worked just
great; they thought it should feel more
solid. Another feature you could miss is
the master-cylinder location, which is
under the fuel tank. BMW builds bikes with
short handlebars, and they like everything
tidy, so instead of attaching a lumpy
mechanism at the brake lever pivot they
tucked the master-cylinder out of sight,
connected it to the lever with a cable-and
installed a brake fluid level sensor and
warning light.
“The brake warning light is up on a panel
that carries the speedo and tach, other
warning lights for the generator and oil
pressure, an amber light that flashes
when the turn signals are going, and a
green light that's supposed to come on
when the transmission is in neutral - but
sometimes doesn't. This neutral indicator
is in the circuit that energizes the starter
solenoid, which means that even if you've
found neutral (no mean feat, in the case
of our test bike) you can't get any action
by thumbing the starter button unless you
pull the clutch lever. There's another
switch included in the clutch mechanism
to override the neutral indicator, so you
can leave the bike in first, leap aboard,
pull the clutch, hit the starter and make
a stylishly fast getaway.
“Those who buy an R90S should consider leaving it in first-gear anytime it is
parked leaned against its side stand.
BMW's generally masterful way with machinery seems to have deserted them in
the design and execution of the hardware
intended to hold the bike upright in its
rider's absence. The side stand is a teetery, spring-loaded strut that is just diabolically eager to fold when you want it to hold. Let the R90S roll forward a couple
of inches and the next thing you know
it has clunked over and is nuzzling the
pavement with its left rocker cover. A
couple of very near misses persuaded us
to make maximum use of the center stand;
that was no joy either Before you can
get the center stand deployed it is necessary to grope around under the bike with
your toe, like a Romeo trying to play footsy
with some lady two chairs away at a
crowded dinner party. Once contact is
made you work the stand down easily
enough - only to find that there's something amiss with contact arcs and fulcrums and you have to haul like mad, on the grab-handle above the left sidecover
to get the bike's weight up, over and
resting securely on the two-legged prop.
“Getting the R90S primed to ride is a
lot easier than propping it up after you've
finished. They've done away with the old
side-winder kick-start pedal (which may
rightly be considered an anachronism),
boosted the starter motor's output by
about 20 percent and installed a battery
that looks big enough to give the BMW
a 50-mile electric-power range after the
gasoline is gone. The battery's size reflects undue pessimism on their part. After
you've hit the lever that opens the Dellorto
carburetors' starting enrichment passages and given the throttle grip a couple
of quick twists to prime the cylinders, no
more than a touch of the starter button
is needed before you get fire and rotation.
When the engine is still semi-warm, ignore
the choke and just prime the engine with
throttle. The BMW R90S carburetors are
virtually unique in the motorcycle field in
having accelerator pumps, which give
each cylinder 0.4cc-squirt of fuel every
time you wind the throttle open.
“Throttle actuation on the first R90S was
mournfully, painfully slow, taking more
grip rotation than the human wrist could
hope to supply in less than two tries.
They've fixed that, and the new throttle
mechanism - which still features a pair of
bevel gears, and a cam winding in a chain
to give progressive action - takes hardly
morn than a quarter-turn to pull the slides
all the way up. This, combined with the excellent response to throttle provided by
the Dellorto's accelerator pumps, could
have made the bike a bit too sudden for
comfort. But the first few degrees of
throttle grip rotation give relatively little
lift at the slides, due to the camming
action of the twist-grip mechanism. It's
only when you move the grip farther
around that slide movement becomes
more rapid. The arrangement is neither
as simple nor as cheap as those found
on other motorcycles; it does work uncommonly well, and helps explain why the
BMW finds so many buyers despite its
intimidating price.
“The R90S is delivered with other price
elevating/justifying features. Like its light
aluminum-alloy wheel rims, which follow
latest motocross practice in being free of
the once-common reinforcing ribs that
always collected unsightly muck. And the
wheel spokes are made of stainless steel,
which is a small item, but important. Other
small, important touches are things like
the weather sealing that keeps water out
of the lift-out tool tray and the odds-and-ends compartment incorporated in the
fairing behind the seat. That fairing is, by
the way, made of the same impact-resistant molded plastic as the side covers and
the small handlebar fairing /windshield.
Plastic is a good material in those applications, just as cast aluminum is right for
the cleated brake pedal.
“BMW has followed longtime habit in
making the grab-it end of the ignition key
shaped like an instrument knob (black
plastic, round and with non-slip serrations) and said key makes an unusually
lumpy object in one's pocket ('Are you
a BMW owner or are you just glad to see
me?') But you do get a pair of separate
fork-lock keys, and the seat latch may be
left unlocked, like a car's glove-compartment door. You can get at the tools without killing the engine because you don't have to use the key to spring the lid.
“Plan to spend your first weeks of BMW
ownership in frequent reaching for the
tool kit. Not because the bike will need
attention; you simply won't be able to
resist showing the kit to your friends. It
has everything: combination wrenches all
the way from 7mm to 22mm in size, a
couple of double-end sockets, a set of
feeler gauges for setting valve clearances
and spark plug and contact breaker gaps.
a set of allen wrenches, the expected
pliers and screwdrivers, an odd-looking
device used to tighten steering-head
bearings and remove fork tube caps, and
two very nice tire irons. You will find that
the feeler gauges are labeled in German,
and we think it only fair to tell you that
Hauptbremszylinder on the forked
feeler means you use it to adjust the free
play at the brake master cylinder.
“With all these wonders, which tend to
make us firmly believe in our theory about
the likelihood of a given motorcycle
needing roadside repair being in inverse
ratio to the quality of its tool kit, perhaps
the most impressive item in the tool tray
is the hand towel with 'BMW' woven right
into its fabric. The towel is just the right
touch, and all the more impressive after
you discover that it is wrapped around
a small box of tire-repair patches, and
then notice the tire pump clamped handily
in place under the bike's seat. You get
all these tools, and they mean something,
because the BMW owners' manual really
is useful. It's the best; better than many
workshop manuals we've seen.
“This latest BMW R90S is improved over
the first version, which we also liked a
lot. Much of the bike is all but unchanged - it still has the small clock,
which still keeps time accurately - but
there are differences and most will not
be found looking at the machine in the
dealer's showroom. The engine's crankcase castings, for example, have been
modified for added stiffness, and the front
main bearing, push rods, cam followers
and rocker arms upgraded. There are
some detail improvements in the transmission, which did not prevent our test
bike from being iffy about engaging 5th
gear, and the clutch linkage has been
rearranged, in minor fashion, to broaden
the engagement point and smooth away
some of the clutch grab.
“One of the nicest changes is in the front
fork damper valving, which has been re-metered to provide an extra measure of
compression damping, which doesn't
keep the R90S from doing a nose-dive
under hard braking but does keep it from
happening quite so abruptly. Stiffer fork
springs are available, and these would
make the bike steadier under the pressure
of a maximum-effort charge; they'd also
make it harsh in ordinary cruising, and
harsh just isn't BMW.
“We note that some of the BMW R90S
models now have Continental tires; others
are fitted with Metzlers. Our test bike had
Continental tires, and we think their performance, on dry roads at least, is superior. It may well be that the Metzlers are better in the wet, and we'd expect them
to be longer wearing because the rubber
compound seems to be a bit harder. You
pays your money and gets whatever tires
happen to come on the bike your dealer
has in stock - unless you can argue him
into a swap, one way or the other.
“With either kind of tire, the R90S is
going to be a remarkable time/distance
machine. The low, narrow bars hunker
you down where the small fairing deflects
the worst of the wind-blast away from your
torso, and the ride and seating will let you
stay with it for hours, as will the huge fuel
capacity. Roads stream by under the
flashing spokes, the exhaust is a civilized,
subdued basso rumble. There's power to
spare, reliability unquestioned, and only
the omnipresent possibility of red lights
twinkling in those big rear-view mirrors
to keep you from giving the R90S its head
and letting it do what it does best - which
is to devour miles in giant bites, in safety
and at gas mileages that would make the
average sedan owner think he'd surely
died and gone to heaven.”
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