BMW R 90 S.
| BMW | |
|---|---|
.jpg) Year of construction 1975 |
|
| R 90 S | |
| Manufacturer | BMW |
| Sales description | R 90 S |
| Production period | 1973 to 1976 |
| class | motorcycle |
| design type | Super athlete |
| Motor data | |
| Boxer engine with two cylinders | |
| Displacement (cm³) | 898 |
| Power (kW / PS ) | 49/67 at 7000 min -1 |
| Torque ( N m ) | 76 at 5500 min -1 |
| Top speed ( km / h) | 200 |
| transmission | 5 courses |
| drive | Cardan drive |
| Brakes | Ø 260 mm double disc brakes at the front, Ø 200 mm drum brake at the rear |
| Wheelbase (mm) | 1465 |
| Dimensions (L × W × H, mm): | 2180 × 740 × 1210 |
| Seat height (cm) | 82 |
| Empty weight (kg) | 215 |
| successor | BMW R 100 S. |
The BMW R 90 S is a motorcycle from BMW with two-cylinder - four stroke - boxer engine . The machine with a displacement of 898 cm³ and an output of 49 kW (67 hp) was the top model of the so-called “dash six” series. A total of 17,465 R 90 S were produced.
history
The R 90 S and its smaller sister models R 90/6, R 75/6 and R 60/6 were manufactured from 1973 to 1976 and were the successors to the "dash five" series (R 50/5, R 60/5 and R 75/5). With almost 200 km / h, the R 90 S was one of the fastest production motorcycles in the world. It arose from efforts by BMW to stand up to the more powerful motorcycles of the competition (e.g. Norton Commando , Moto Guzzi V7 , Laverda 1000 , Kawasaki Z1 , Honda CB 750 Four , Harley-Davidson 1000).
At the same time were in the BMW plant in Berlin also essentially and equipment same smaller displacement models chassis R 75/6 (37 kW), replacing the R 75/5 and the R 60/6 (30 kW), replacing the R 60/5 built. There was no longer a model with a displacement of 500 cm³ as the direct successor to the 24 kW (33 PS) R 50/5 .
R 60/6
R 75/6 745 cm 3
R 90 S
technology
The transmissions of the "Stroke Six" series had five gears for the first time. The crankshaft was changed: From this engine series onwards, it is balanced with heavy metal plugs, which makes the outer diameter of the crankshaft smaller and makes installation and removal easier. The "dash-five" engines have forged steel weights on the crankshaft; Their crankshafts can only be threaded through special recesses in the engine housing with great practice. The engine housings of the 900 engines became considerably more stable after it had been found in an experiment with the previous model that the old housing could no longer carry the higher forces of larger cylinders.
In order to do justice to the increased performance compared to their predecessors, the 900 and 750 models received a front disc brake system for the first time (swivel caliper brake from ATE , an unusual variant of the floating caliper brake ). In machines with disc brakes, a Bowden cable operates the main brake cylinder under the fuel tank. From there hydraulic lines lead to the brake calipers. Only the R 60/6 had standard nor a front duplex - drum brake . But hardly anyone left them, but ordered a disc brake when they bought it. Therefore, the original R 60/6 with drum brakes are a rarity today . Many of the smaller models also received the double disc brake of the R 90 S; because retrofitting to two brake disks at a later date is very time-consuming, as the immersion tube on the “brake-free” side is not prepared to accommodate the second brake caliper and therefore has to be replaced. The rear brake is operated mechanically with a foot lever.
All models have a double loop tubular frame and cardan drive to the rear wheel. Compared to the “Stroke Five” series, the wheelbase was extended by 80 mm to 1465 mm, which on the one hand weakened the load change reactions of the cardan drive and on the other enabled the installation of a larger starter battery .
The motorcycle accelerates from 0 to 100 km / h in 4.8 seconds and reaches a top speed of 200 km / h.
General
The R 90 S was the first production motorcycle in the world to have a sleek, handlebar-mounted cockpit fairing made of fiberglass-reinforced plastic and a rear bumper. It was initially only offered as standard in smoky silver and from 1975 also in Daytona orange. This BMW was also designed by Hans A. Muth.
In autumn 1976 the R 90 S was replaced by the R 100 S and R 100 RS models . In the new "Strich-Sieben" series there was still the R 100/7 , R 75/7 (replaced by the R 80/7 in 1977) and the R 60/7.
Technical specifications
| R 60/6 | R 75/6 | R 90/6 | R 90 S | |
|---|---|---|---|---|
| number of pieces | 13,511 | 17,587 | 21.097 | 17,465 |
| Front brake | Duplex drum | a disk | two discs | |
| optional | one or two slices | two discs | ~ | |
| rear brake | Simplex drum | |||
| Carburetor | Bing slider 26s | Bing equal print 32s | Dell'Orto slider 38 mm | |
| Bore (mm) | 74 | 82 | 90 | |
| Stroke (mm) | 70.6 | |||
| Displacement (cm³) | 595 | 745 | 898 | |
| Power (kW / PS) | 30/40 | 37/50 | 44/60 | 49/67 |
| Top speed (km / h) | 167 | 177 | 188 | sitting upright 195 lying down 200 |
| Empty weight kg) | 210 | 215 | ||
| Total weight (kg) | 398 | |||
| Wheelbase (mm) | 1465 | |||
| Tank capacity (l) | 18 or 24 | |||
| Price 1973 (DM) | ~ | ~ | 7150 | 8510 |
Reviews
“The new engine with thick 90's pistons developed a whopping 67 hp and was thus finally up to date in terms of performance. And that with just two cylinders and a VW Beetle valve control via bumpers and rocker arms. If you look at an R 90 S like this today, you start pondering. BMW was actually able to build lean, pared-down machines once. The lines are clear and soft, the engine, fork and two struts are almost delicate - that's what it actually does. "
“Oil fumes contaminate the air filter element, which needs to be replaced frequently. There were problems with the gearbox at the beginning of the series. The newly developed transmission, now with five gears, often had to be replaced. Especially when it is cold, there is a cruel crack from the switch box and makes BMW newbies worry about the end of the transmission gears. Anyone who is used to speedy downshifts on a modern motorcycle will have to rethink the R 90 S. She doesn't like that at all. She acknowledges such an act of violence with a clearly noticeable restless hindquarters. The cardan shaft and the long spring travel ensure pronounced load change reactions. "
literature
- Hans-Jürgen Schneider: BMW R 45 - R 100 RS from year of construction 1976 . BLV Auto- und Motorradpraxis, Munich 1984, ISBN 3-405-12908-7 , p. 127 .
- Michael Morley, Mike Woollett, Riegel: BMW motorcycle classics - from the R 32 to the "new generation" . Heel Verlag, 2002, ISBN 3-89880-080-6 , pp. 252 .
- Andy Schwietzer, Werner R. Reiss: BMW Boxers all from '5. BMW two-valve engine from 1969–1985 . 1st edition. Bodensteiner Verlag, Wallmoden 2006, ISBN 3-9806631-4-0 , p. 176 .
- Nürburgring test R90S . In: The motorcycle . No. 20 . Motor-Presse-Verlag Stuttgart, 1973, ISSN 0027-237X .
- Which to choose? In: The motorcycle . No. 20 . Motor Presse Stuttgart , October 5, 1974, ISSN 0027-237X .
- “The Taming of the Shrew”, endurance test BMW R 90 S over 30,000 km. In: motorcycle. Issue 1/1976 from January 10, 1976, Motor-Presse-Verlag Stuttgart.
- Hans-Joachim Mai: 1000 tricks for fast BMWs. 11th edition. Motorbuch-Verlag, Stuttgart 1988.
See also
Web links
- Wilhelm Hahne: A fun device for lion tamers . In: motor-kritik.de , September 3, 2001.
- Jens Schlichting: BMW R 90 S, built in 1976: 25 years, 250,000 kilometers . In: Spiegel Online . October 15, 2007.
- A "rubber cow" is punching her way up . In: Handelsblatt . July 2, 2008.
- Model of the BMW R 90 S . In: radrennen-wasser.de .
Individual evidence
- ↑ Ulrich Feld: This bike completely redefined BMW motorcycles. In: T-Online . August 16, 2013, accessed May 1, 2014 .
- ↑ a b Michael Pfeiffer: Give rubber, cow! (No longer available online.) In: Motorrad , issue 12/2009. May 22, 2009, archived from the original on February 1, 2014 ; accessed on May 1, 2014 .
- ^ Konstantin Winkler: Driving report. In: Kradblatt. October 1, 2003, accessed May 1, 2014 .
