Lot 260: 1928 BMW 486cc R52

Following the collapse of its aero engine business after WWI, BMW turned to other areas of manufacture, motorcycles among them. Its first two models, marketed as the Frink and Helios respectively, were failures, but a successful proprietary engine was supplied to other manufacturers. Launched in 1923, the first motorcycle to be sold as a BMW - the R32 - featured a 493cc, twin-cylinder, sidevalve engine having horizontally opposed cylinders, and this ‘flat twin’ layout would forever be associated with the marque. Setting a pattern that endures to this day, the first BMW motorcycle was relatively expensive but superbly engineered and constructed, while the quality of finish was of the highest order. Before long BMW updated its original tourer, which in 1926 became the R42, gaining a redesigned and more powerful engine boasting detachable alloy cylinder heads and cooling fins set at 90 degrees to the cylinder axis. The engine was set further back in the duplex loop frame, which improved weight distribution and enabled straight front down-tubes to be used. The braking too came in for attention: the old block-and-pulley type rear brake being replaced by a drum on the driveshaft gripped by external contracting bands. Electric lighting was still regarded as an ‘extra’ and would not be standardised until 1928.

That same year BMW revised its range of engines and added a brace of 750s, adopting a long (78mm) stroke for the sidevalves and short (68mm) stroke for the overhead-valve models. Thus the sidevalve-engined R52 employed bore/stroke dimensions of 63x78mm for a capacity of 486cc, and in addition featured the newly redesigned gearbox, common to all models, which incorporated a side-throw kick-start and direct gearchange, the lever now being mounted on the ’box rather than the engine. BMW motorcycles evolved quickly throughout the 1920s, and the range in this form lasted only until the end of 1929 when a switch to pressed-steel frames was made. As a result, the R52 was produced for barely two years and today this rare Vintage BMW is among the marque’s most desirable and sought after machines of the period.

This R52 was acquired by Brian Verrall in 2004, having previously belonged to another Surrey-based enthusiast, Wally Lambert. An excellent example of the marque, the machine is featured in the Osprey book ‘BMW Motorcycles’ by Don Morley and Mick Woollett. ‘DS 9811’ carries a tax disc dated July 1997, presumably the last occasion that it was licensed for the road, and is offered with two expired MoTs (1994-1995 and 1996-1997), illustrated parts list, (copy) old V5 registration documents, assorted technical literature, VMCC dating certificate, a quantity of photographs and Swansea V5C registration document.