Editing BMW R90S AMA Racer

{{Infobox Motorcycle
|name             = Racing Bikes BMW R90S AMA Racer
|image            = [[File:bmw-r90s-ama.jpg|frameless|Racing Bikes BMW R90S AMA Racer]]
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== Photos ==
[[File:bmw-r90s-ama.jpg|600px|Racing Bikes BMW R90S AMA Racer]]

== Overview ==
BMW R90S AMA Racer





Introduced in 1973, the R90S is considered by
many to be one of the first superbikes, and the first such motorcycle from
BMW. The first United States AMA Superbike Championship was won in 1976 by
British rider Reg Pridmore on a R90S. The motorcycle offered features the oil
filter system patented by Woody Shrider. Offered on a Certificate of Title.

Overview

Over 33 years ago, in 1976, Peter Adams, owner
of BMWs US importers, Butler & Smith, decided to confront the same issue,
which led to BMW dominating the first-ever Superbike championship, with its
team of R90S Boxers, brewed in-house at Butler & Smiths New Jersey HQ by an
R&D team, led by Udo Geitl, with mechanics Todd Schuster and Kenny Augustine.
Not only did BMW rider Steve McLaughlin  the
man who, a decade later, created the World Superbike series  win the
first-ever Daytona Superbike race from team-mate Reg Pridmore, but it was the
California-based Pridmore, a transplanted British sidecar driver, who went on
to clinch the inaugural AMA Superbike title.
1976 was the battling Boxers single Superbike
season in the sun, and came as the culmination of a five-year race programme,
funded by the Adams family after they purchased New Jersey-based Butler &
Smith in 1971. It was aimed at removing the stuffy pipe-and-slippers image and
rejuvenating sluggish sales of its R75/5 roadsters.
Initially they funded their parts manager, and
part-time racer, German-born former NASA engineer Udo Geitl, to develop a F750
racer, based on the 75/5 Boxer, which was outclassed by Suzuki and Kawasaki
two-strokes in AMA Nationals. Even wrapping the Geitl-tuned motor in a Rob
North chassis for 1974, didnt improve matters, and the debut that year of the
Yamaha TZ750 simply meant that, like all four-strokes, the BMW racers were
outclassed. Gary Fishers achievement in qualifying his Rob North BMW on the
front row of the grid for the tight, twisty Laguna Seca AMA National in 1975,
then battling for the lead with future world champion Kenny Roberts Yamaha,
before the BMWs monoshock suspension failed, represented a glorious finale.
The 1974 arrival of the R90S in the BMW range
presented Butler & Smith with a much better arena for demonstrating the worth
of its products. The new 898cc Boxer was more than capable of competing on
equal terms in the Heavyweight Production class. With Butler & Smiths new LA
office now headed by the companys former service manager and race fan Helmut
Kern, backed by sales manager Matt Capri, the way to promote BMWs new
sportbike was to go production racing, and win.
Reg Pridmores success racing the R75/5 in
Californian 750cc and Open Production events, for Butler & Smiths West Coast
office, had already led to his nomination by Geitl to race the unsuccessful
F750 bikes for the team, run out of the firms East Coast HQ. But the R90S was
a different matter, and in a one-off AMA National ride at Ontario in 1974 he
finished so far in front of second place finisher, Yvon DuHamel, and third
placed man Steve McLaughlin, on their Kawasakis, that they were shocked to see
him in Victory Lane. What are you doing here? asked DuHamel, I thought you
crashed? Pridmore continued to race the BMW in Heavyweight Production races
with some success, finishing fourth at Daytona in 1975  but it wasnt until
the AMA created the Superbike series that BMW really made its mark.
With the TZ Yamaha swamping F750 entry lists
and AMA Nationals, proving a switch off for four-stroke focused race fans, the
AMA decided to establish the new Superbike class for 1976 for modified street
bikes, and Peter Adams came up with a budget reputed to be a then massive
$250,000 for Butler & Smith to win the title.
The three bikes made their debut at Daytona in
March 1976, in the hands of Pridmore, two-stroke racer Gary Fisher, and
Californian Steve McLaughlin. Originally Geitl intended to run two bikes, but
Peter Adams wanted to try to fill Victory Lane with BMW Boxers, and insisted
on a third rider chosen by the companys Californian office. Serious internal
rivalry existed between the companys two geographic opposites. Which explains
why Kern and Capri were astounded to discover that Geitl had developed a
monoshock rear suspension for two of the three Superbikes, after a creative
reading of the Superbike rulebook which he helped draft, as a member of the
AMA Committee.
Pridmore declined to race with a monoshock, on
the grounds that he couldnt get on with it, though it was widely speculated
that BMW welcomed this in case the tech inspectors rejected Geitls
interpretation of the rulebook.
All AMA road race grids were determined by heat
races, and these, held on Thursday saw Peter Adams wish for a one-two-three
BMW blanket finish come true, with Fisher an easy winner, Pridmore second and
McLaughlin close behind. Cook Neilson (883 Desmo Ducati) finished fourth,
ahead of Mike Baldwin on Reno Leonis Moto Guzzi 850.
The final saw Neilson lead off the line, before
dropping back as Fisher passed him on the BMW, followed by McLaughlin and
Pridmore. Fisher continued to lead until a loose exhaust clamp rotated and
interfered with his gearchange, causing him to miss gears, leading to a broken
rocker.
McLaughlin now had the lead, and being a
student of the Art of the Draft, and knowing he had no chance of pulling
away allowed Pridmore to lead into the last lap, then lined up to slipstream
past on the banking before the finish line. He almost didnt make it, rubbing
cylinders with his team-mate as they droned towards the stripe. In the final
few yards the West Coast monoshock bike went ahead, for McLaughlin to win by
three inches, or less than the width of a tyre. The Ducati was third, Wes
Cooleys Yoshimura Kawasaki fourth and Baldwins Guzzi fifth.
The publicity for this one-two victory, at a
crucial time in the calendar, would have justified Adams investment, with
dealers selling R90S as fast as Butler & Smith could deliver them. BMWs
fuddy-duddy reputation transformed overnight.
But there was still a championship to be won,
and in the next round at Loudoun, Baldwin scored a decisive victory over
Pridmore on the BMW. Daytona-winner McLaughlin sheared the flywheel off his
Boxer.
For the third round at Laguna Seca Geitl
equipped the three BMWs with much larger Hurst-Airheart front brakes, matched
to Lockheed two-piston calipers. Fisher retired early with a leaking oil
cooler, leaving Pridmore and McLaughlin to battle for victory.
On the final lap, with Pridmore ahead,
McLaughlin experienced the full potential of the better brakes to the max,
performing a gigantic stoppie to avoid ramming his team-mate. The
Daytona-winning bike cart wheeled and flew through the air having already
decanted its rider. Photographer Mush Emmins was there to capture the moment
and when it appeared in Californias leading daily paper, the Los Angeles
Times it made McLaughlin famous outside the world of motorcycling, for all the
wrong reasons! Pridmore went on to win the race and the inaugural AMA
Superbike title with another victory in the final round at Riverside, his home
track.
With the PR mission accomplished and the BMW
image transformed, Butler & Smith race mechanic Todd Schusters Bavarian
Murder Weapons tag summed it up nicely. Peter Adams shut the race operation
down, sending the three Butler & Smith bikes out West, where they ended up in
the hands of various BMW dealers.
The rebuilt McLaughlin Daytona-winner went on
to take victory in the hands of Ron Pierce in the 1977 Loudoun AMA Superbike
National, a win repeated the following year on the same track by Harry
Klinzmann on the Fisher bike, by now owned by San Jose BMW, the German
marques final race victory in AMA Superbike.
Adams appointed Geitl as B&S Service School
Manager, but with permission to continue running a new bike at his own expense
in conjunction with Todd Schuster, first with McLaughlin, then in 1978, John
Long. In the final chapter Long won the Canadian Superbike title, and tied
with the now Kawasaki-mounted Reg Pridmore for the AMA championship, before
being declared the winner on count back. Several months later Longs title was
rescinded, owing to a purported start line error at Loudoun, when the BMW
rider was waved into the wrong place on the grid by an AMA official. To most
minds BMW actually won two AMA Superbike titles with their improbably
successful battling Boxers.
TECHNICAL SPECIFICATION
ENGINE
Air-cooled pushrod ohv 180 degree Boxer twin cylinder 4-stroke
DIMENSIONS 95 x 70.6mm
CAPACITY 1001cc
OUTPUT 102bhp @ 8600rpm (at clutch)
COMPRESSION RATIO 12.6:1
CARBURATION 2 x 40mm Dell'Orto with accelerator pumps
IGNITION Bosch CDI with dual ignition and 4 coils
GEARBOX 5-speed close-ratio with shaft final drive
CLUTCH Single-plate all-metal diaphragm with steel flywheel
unit
CHASSIS Tubular steel duplex cradle with dual reinforcement
struts
SUSPENSION Front: 36mm BMW leading-axle telescopic forks with
three triple-clamps
Rear: Tubular steel swingarm incorporating shaft final drive inside right leg,
with cantilever Koni monoshock
HEAD ANGLE 28 degrees
TRAIL 80mm
Wheelbase 1465mm
Weight 175kg with oil, no fuel
WEIGHT DISTRIBUTION 48/52 per cent with 12 liters
fuel
BRAKES Front: 2 x 290mm Hurst-Airheart steel discs with 2P
Lockheed calipers Rear: 200mm BMW single leading-shoe drum
WHEELS/TYRES Front: 110/60-18 Metzeler Lasertec on 2.65in WM4
wire- spoked rim
Rear: 130/80-18 Metzeler Lasertec on 3in WM5 wire- spoked rim
TOP SPEED 144.5mph/233kph (Daytona 1976)
YEAR OF MANUFACTURE 1976
OWNER BMW Mobil Tradition, Munich, Germany
Source
== External Links ==
* http://www.classicracer.com/ft1.htm

[[Category:Racing motorcycles]]