BMW R 26
| BMW | |
|---|---|
 BMW R 26 from 1960 |
|
| R 26 | |
| Manufacturer | BMW motorcycle |
| class | motorcycle |
| design type | Tourer |
| Motor data | |
| Single-cylinder four-stroke - OHV -Motor | |
| Power (kW / PS ) | 15/11 at 6400 rpm |
| Top speed ( km / h) | 128 |
| Empty weight (kg) | 158 |
| Previous model | R 25/3 |
| successor | R 27 |
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The BMW R 26 is a single cylinder motorcycle manufactured by BMW from 1955 to 1960 .
previous version
The predecessor of the R 26 was the R 25/3 model with 9 kW rated power, telescopic fork and straight-travel rear wheel suspension . The R 26, which was built from 1955, differs from it with a more powerful engine and a full swing frame . The disadvantage is the high weight of the machine in connection with the relatively low performance despite the increase. One advantage of the R 26 is its solidity.
Design features
The frame is welded from tubular steel and has ball heads attached to the side for sidecar operation , which requires a special gear ratio of the cardan drive. On later R-26 models (from chassis number 344637) a subframe had to be installed for the sidecar connection. The Steib LS 200 and S 250 are suitable sidecar types. The caster of the front wheel can be adjusted individually for solo and team operation. The free hole on the front swing arm is used to change the caster for sidecar operation. The preload of the rear suspension can be adjusted directly on the struts without tools. A lever on the rear swing arm strut enables the preload to be adjusted.
engine
The motor is as its predecessor R 25/3 a longitudinally mounted single-cylinder four-stroke cycle - OHV engine with side camshaft running and outside beside the cylinder in chrome protective tubes bumpers . These operate the rocker arms in the cylinder head , which in turn operate the hanging valves. Like the piston pin , the rocker arms are mounted in bronze bushings , the lower connecting rod bearing is a roller bearing . The camshaft is driven by the crankshaft via a single chain running in an oil bath . The gear oil pump is driven by the camshaft via a worm drive ( reduction ).
The splash-proof encapsulated direct current alternator sits on the front crankshaft stub behind the sheet steel cover . On the rear stump of the crankshaft sits the heavy flywheel (with the ignition timing mark that can be seen in the peephole), which holds the dry single- disk clutch . The clutch is operated with a thrust bearing via a push rod that runs through the hollow main shaft of the gear unit.
The carburetor is a Bing float chamber carburetor with a 26 mm passage diameter and a conical needle in the round slide. The air filter is located on the right side cover. It is a wet air filter, the sieve of which is washed when dirty and moistened with oil. The electrics and the battery are located under the left side cover .
The engine block and gearbox are made of cast aluminum . The engine of the BMW R 26 is mounted in rubber bushings at two points on the frame. The muffler is elastically mounted to keep vibrations from the frame.
drive
The drive train has an angularly movable torque transmission element at the transmission output. For this purpose, an elastic four-hole rubber disc ( Hardy disc ) is pushed onto the two-finger flange of the gearbox, which transfers the torque from the gearbox output shaft to the two-finger mount on the cardan shaft. An aluminum cap encloses the hardy disc. The cardan shaft, actually a rigid shaft, runs dry to the rear wheel in the steel tube of the rear wheel swing arm, which at the end accommodates the angular gear with 90 ° deflection in a cast aluminum housing. As a result, the entire drive train is encapsulated against dirt and moisture. The gear wheels of the deflection gear run in a special heavy gear oil for high flank pressures (hypoid oil).
Construction end
The R 26 was replaced in 1960 by the BMW R 27 model , again with a more powerful engine (13 kW / 18 hp) and a completely redesigned elastic suspension of the engine-transmission unit.
BMW R 26 as a government motorcycle
The R 26 model was also purchased in the Bundeswehr in standard Bundeswehr paintwork, in cream paint for the Red Cross and in police green (the old, dark police green) from the police, mostly for training purposes. Tens of thousands of soldiers in the 1960s and 1970s learned to ride a motorcycle on the R 26 and R 27.
See also the general article full swing BMW and the successor model BMW R 27 .
The color options of the machine are interesting: black, red, blue, white, sometimes even two-colored, always with two circumferential, hand-painted, usually white, decorative lines. The original color scheme was mostly black with white lines, more rarely white with black lines. Red is said to have been sold optionally with black or white lines.
Technical specifications
| Parameters | R 26 |
|---|---|
| design type | Single cylinder with cardan |
| engine | Four-stroke OHV |
| Bore (mm) | 68 |
| Stroke (mm) | 68 |
| Displacement (cm³) | 247 |
| Power (kW / PS) | 11/15 at 6400 rpm |
| Compression ratio | 1: 7.5 |
| Standard consumption (l / 100 km) | 3.9 |
| V max (km / h) | 128 / with sidecar 90 |
| Wheelbase (mm) | 1390 / with sidecar 1415 |
| Empty weight kg) | 158 |
| Total weight (kg) | 325 / with sidecar 480 |
| Tank capacity (liter) | 15th |
| construction time | 1955 / 1956-1960 |
| number of pieces | 30,236 |
Web links
- BMW R 26. In: BMW History. BMW AG, accessed on October 7, 2019 (dossier from the BMW Group Archive).
- Handbook motorcycle R 26. (PDF) In: BMW history. BMW AG, January 1956, accessed on October 7, 2019 (manual with pictures, 82 pages).
Individual evidence
- ^ Wolfgang Zeyen, Jan Leek: BMW - The motorcycles since 1923 . Motorbuch Verlag, Stuttgart 2004, ISBN 3-613-02401-2 , p. 150.
