I got a heads-up that this machine is shortly coming up for sale from Jared Zaugg; now Bonhams has issued a press release with a photo. It's quite rare for any pre-1900 motorcycle to come up for sale, but the Hildebrand & Wolfmüller is the granddaddy of our whole two-wheeled family, the first machine to be called explicitly a motorcycle ('motorrad' auf Deutsche), and the first in any reasonable series production. And this machine is an original condition, original paint example.
From the Bonhams press release:
"The Hildebrand brothers, Henry and Wilhelm, developed their motorcycle in partnership with Alois Wolfmüller and his mechanic, Hans Geisenhof. Their design was powered by a twin-cylinder, water-cooled, four-stroke engine displacing 1,488cc, which until relatively recent times was the largest power unit ever fitted to a motorcycle. Despite a maximum power output of only 2.5bhp at 240rpm, the H&W was capable of speeds approaching 30mph, an exciting prospect at a time when powered road transport of any sort was still a novelty.
Patented in January 1894, H&W’s motorcycle was greeted with considerable enthusiasm and plans were drawn up to build a factory in Munich to produce it. It was also licensed to a firm in France and marketed there as ‘La Petrolette’. Despite some impressive demonstration performances by factory riders, the H&W’s shortcomings became all too apparent once deliveries to paying customers commenced, and early in 1897 both the German and French ventures collapsed. Opinions differ with regard to how many machines were produced, figures range from as low as 800 to as high as 2,000. Survivors are, needless to say, exceedingly rare. The example we offer has been in the ownership of the vendor’s family in the USA since at least the early 1930s, which is when it last ran. Presented in original, unrestored condition, this wonderful machine represents the ultimate acquisition for the serious private collector or any museum devoted to the history of powered transport and is estimated at £40,000 – 60,000."
Replicas of the H&W were made in Germany a several years ago, which have come up for auction, but I've seen one other Original Paint Unrestored example (all other photos), at the Deutches Zweirad Muzeum in Neckarsulm (the 'N' in NSU), which is in truly astounding condition.
Below is a short film of the former museum curator Peter Kuhn (with NSU guru Wolfgang Schneider translating) energetically explaining the function of the H&W. And no, we hadn't had a 3 bier lunch! Just kids having fun in the back room with the toys.
The design of the H&W seems unorthodox today, as we've 'settled' on a particular arrangement of valve actuation, water cooling system, carburation, and rear wheel drive, but in the 1800's, the established norm of powered transport was the train, and the designers of the H&W clearly took some of their inspiration from the rails. Notable is the rear-wheel drive; as seen in the photo below, the connecting rod is directly attached on an eccentric 'crankpin' to the rear wheel, which is a de facto flywheel. Note the rubber band in the video; this can be tightened by means of a small crank, to give a bit more urge for starting.
Most intriguingly, the rear wheel also contains the camshaft! The smaller rod in the photo has a roller cam follower riding on a ring camshaft attached to the wheel - this is a pushrod for the exhaust pair of the four overhead valves. A system of articulated rods and levers pushes the exhaust valves open in concert with rear wheel motion (the inlets are 'atmostpheric', ie use piston suction to open valves with weak springs); very direct, very clever, and a design solution which wasn't pursued further, as it soon became apparent that using the rear wheel as the crankshaft led to a host of problems, as you can imagine. Grandpa wasn't perfect, but he was damn clever.
The engine is water-cooled, and the carburation is expectedly crude. If you've seen a replica H&W up close, you've noted the charming enamel plaque in front of the handlebars (a bald monk in a brown robe!), which is actually the breather for the flame of the hot tube ignition. It seems to be missing from the auction machine - replaced by an acetylene gas lamp. Still, this machine represents an incredible opportunity to own one a real example of the most important motorcycles in the world.