1938 BMW R66 – A Pinnacle of Pre-War Motorcycle Engineering

The 1938 BMW R66, now on display at our New Milford CT location, is a remarkable example of BMW Motorrad’s pre-war innovation, representing the pinnacle of their overhead-valve (OHV) sports roadsters. Introduced in 1938 alongside the R51, R61, and R71, the R66 featured a significant advancement: a tubular steel frame with straight-travel plunger rear-wheel suspension, a carryover from the successful 1937 Six-Day Trial Race. This new suspension, paired with a telescopic front fork with hydraulic damping, marked a leap in ride comfort and handling, though it increased the bike’s weight to 187 kg (412 lbs) compared to its unsprung predecessors.

Engine and Performance: The R66 was powered by a 597cc OHV flat-twin boxer engine, derived from the side-valve R6 power unit but upgraded with a single gear-driven camshaft, unlike the R51’s dual chain-driven camshafts. Producing 30 horsepower at 5,300 rpm, the R66 achieved a top speed of 145 kph (90 mph), making it BMW’s fastest pre-war motorcycle and one of the most powerful of its time. Designed as a sporting sidecar mount, it was equally capable as a solo bike, offering exhilarating performance for enthusiasts.

Provenance and Rarity: This particular R66 has a fascinating history. Sourced from a retired master mechanic in Germany with 50 years of experience, it was a coveted addition to a dedicated collector’s list of dream BMWs. After faxing his wish list to contacts, the collector received a response confirming the availability of this R66, which had been preserved in museum storage for the past 30 years. With only 1,669 units produced between 1938 and 1941, the R66 is exceptionally rare and was one of the most expensive and exclusive motorcycles of its era. Its time in museum storage likely contributed to its well-preserved condition, making it a significant find for collectors and historians.

Historical Context: The R66’s advanced features, including its plunger rear suspension and OHV engine, reflected BMW’s push for performance and innovation in the late 1930s. The bike’s design catered to both solo riders and sidecar enthusiasts, with a robust shaft drive and a 4-speed transmission (featuring both hand and foot shifters for versatility). The hand shifter, mounted on the right side of the transmission, allowed precise gear selection, easy neutral finding, and was favored by racers for aerodynamic positioning. Its tubular frame, shared with the R51, was a significant evolution from earlier pressed steel designs, offering improved strength and handling.

The R66’s has moved from a German master mechanic to museum storage in the US and now to public display at our Connecticut location. This gives enthusiasts a rare opportunity to appreciate a meticulously preserved piece of BMW Motorrad history and maybe even add to your own collection