c.1938 BMW R51 Twin Cam Racer
For the first 15 years of its existence, the BMW motorcycle range was not considered to be at the forefront of suspension technology or exemplars of fine handling characteristics, relying on rigid rear frames and leaf-strung, short-link forks up front. In racing as on the road, BMWs always held esteem for the quality of their built, their elegant lines, and their luxuriously smooth ride from perfectly balanced flat-twin engines. BMW's reputation changed dramatically in 1935 with the introduction of the world's first 'modern' telescopic fork on the R5 model, a radical new motorcycle which launched the factory into the modern era. The engine used quiet timing chains to spin twin camshafts on the short-stroke motor, which had in previous models been a noisy gear drive with a rather agricultural note. The new four-speed gearbox incorporated a foot shift, and most significantly, the frame, while still rigid at the rear, was welded up from lightweight, tapered tubing. The overall effect of these changes was a model which was lighter, more nimble, and faster, with excellent handling and comfort, thanks to the new teleforks.
BMW went one better in 1938 with the introduction of their first fully-sprung model, the R51, which kept nearly all the characteristics of the R5, plus the addition of an undamped 'plunger' suspension at the rear. BMW had built a truly sporting motorcycle with a chassis on par with the best in the world, and their racing 'Kompressor' models won the World Championship that year. Naturally, owners with racing pretensions set about tuning their R51s, which proved fast and reliable privateer racers.
This 1938 BMW R51 is an example of such an enthusiast-built racing machine, emulating its Rennsport cousins with racing fuel tank, shortened mudguards, full-width racing wheel hubs front and rear, tapered megaphone exhausts, aluminum wheel rims, rearset foot controls, and a Schorsch Meier racing seat for 'getting down to it'. The engine on this machine was fully rebuilt in 2003 by Chris Hodgson of San Jose BMW.