The modern bike's grandfather
After WWII, the Germans weren't allowed to compete in international motorsports — mostly because of that whole WWII thing — so when they were finally allowed back in during the 1950s, BMW had more pent up energy than a puppy. Rather than chew on shoes, they unleashed all that energy in the form of this 1954 Rennsport RS54 motorcycle, which is hitting the blocks at Bonham's Motorcycle Auction.
The motor was state of the art at the time, originally designed to be supercharged (!) before being heavily reworked to still put out 45 horsepower, so it could propel a legitimately competitive race bike that you could also drive on the street.
The fully closed frame was considered pretty advanced for its day, and as a result, the whole bike weighed just over 600 pounds — more than 30 percent lighter than any of its main rivals. The front suspension on this thing was so good that BMW wound up using it on all its bikes several years later.
While the term "cafe racer" might be somewhat derogatory toward sport bikes that, despite outtwardly looking kinda like the RS54, are just ridden from coffee shop to coffee shop, this one's the real deal, capable of winning races that don't involve pumpkin spice.