1954 BMW R 26
DESCRIPTION & COMMENTS
Right from the start of its founding days, Bayerische Motoren Werke (BMW) AG achieved motorcycling fame and fortune with its legendary ‘Boxer-twin’ engine design. At the same time BMW also produced successful BMW ‘Mono’ motorcycles – single-cylinder powered bikes that were affordable and equally hardy as the twin-cylinder machines. Arguably the most famous and desired of these spirited workhorses were the R 26 and R 27 models of the 1950s to 1960s.
In 1956, BMW released the R 26. This machine was another single-cylinder and again was designed to be affordable with a price of 2,150DM. But at the same time it came with all the usual chassis and engine updates as seen on the twin-cylinder bikes.
The R 26 chassis consisted of a steel tubular frame with rear swinging arm suspended by two rear shock absorbers featuring coiled spring and damper units. Surprisingly BMW saw fit not to produce the R 26 with the proven hydraulic telescopic forks. Instead the R 26 was decked out with the heavier Earles leading-link front fork – first used on a road-going production bike in 1955 with the R 50 and R 69 models.
The resulting anti-dive properties of the Earles front fork along with the single-cylinder’s lower running weight made braking and steering even more ponderous on the R 26 than it did on the heavier twin-cylinder models. Riders of the R 26 quickly learned that although the full-width front brake hub wasn’t particularly strong in action, it was necessary to make good use of it and the rear brake while still in a straight line – if enough speed was not scrubbed off then braking mid-turn would cause the R 26 to ‘sit up’ and bike and rider could miss the important apex point all too easily.
Powering the R 26 was a single-cylinder four-stroke engine of 247cc from the tried and tested bore and stroke of 68 x 68mm. The OHV (Overhead Valve) engine was fuelled by a Bing carburettor (type 1/26/46) and had a compression ratio of 7.5:1. The resulting power of 15HP was delivered at 6,400rpm. Although the engine wasn’t radically tuned, the engine quickly earned a reputation for vibration affecting the rider’s extremities (hands, toes etc). This was made worse when the R 26 had a sidecar attached with a full load even if the drive ratios had been changed to the required specification. The advancement of ignition timing was now in full swing, and as it used the camshaft for actuation it meant reliable and easy to maintain sparking of the combustion mixture. The R 26 still ran with 6v electrical power.