Ardie, a name with a permanent place in German motorcycle history, is best known for its powerful two-stroke engines and four-stroke models with JAP built-in engines. But in 1936 and 1937 Ardie released its own four-stroke engine: the RBU 356/350, a rare model of which only 835 examples were built. A truly rare pleasure! Marina Block wrote about it for the May issue Auto Motor Klassiek an article about. You can now find that issue in stores for a few more days, until Tuesday.
Design and specifications
The RBU 350, also called “Waldläufer”, was a touring motorcycle with a 350 cc side valve engine. The motorcycle was designed for comfort and practical use, with a large floating seat, adjustable suspension, and large knee pads. The four-speed gearbox was easy to operate via a switch on the tank. Despite its good features, the RBU 350 was somewhat dwarfed by the larger two-stroke models and was more expensive in comparison.
Takeover and changes
After the death of the founder in 1922, the Bendit brothers took over Ardie and brought the brand some successes in racing. However, the rise of fascism in Germany forced the Jewish brothers to leave the country, putting an abrupt end to Ardie's sporting successes. Ardie switched to Bark and later Küchen engines, which diluted the sporty image.
Rolf's discovery
Rolf, an avid DKW enthusiast, discovered an Ardie RBU 350 in the collection of a local motorcycle clubmate. This original, unrestored motorcycle immediately caught his attention. After some bartering, Rolf became the proud owner of this rare motorcycle.
Restoration adventure
Although the motorcycle was largely complete, some parts were missing such as the speedometer and taillight. With the help of club members and a lot of patience, Rolf collected the necessary parts and started the restoration. He kept the appearance authentic, with respect for the traces of time.
The overhaul of the engine was a big job: new piston, honed cylinder, and reground valves. Rolf repaired the spark plug thread and made a new cylinder head gasket himself. The engine and gearbox bearings were also replaced, and the oil supply was improved. The alternator and regulator appeared to be in good condition, and after a thorough cleaning everything worked properly.
The wheels received new tires and bearings, and the brakes were renewed. With the technical condition of the RBU 350 almost as new again, nothing stood in the way of a nice tour. This unique Ardie, with its original paint and intriguing history, is a real eye-catcher.
Specifications
- Motor: single-cylinder side valve, alloy cylinder head
- Cylinder capacity: 343 cc
- Power: 10 hp at 4500 rpm
- top speed: approx. 90 km/h
- Gear box: Four-speed, manual transmission
- Remmen: Sachs drum brakes
- Weight: approx.135 kg
- Production period 1936-1938
This rare Ardie RBU 350 from 1937 is a special piece of motorcycle history, with a story that commands admiration.
Speaking of a homemade head gasket, I was 23 years old when I had a boyfriend with
a BSA 500 one cylinder, this 500 was known as a foot breaker when you started pedaling you had to pedal hard all at once, my friend had a broken foot as a result, later he made a homemade red copper head gasket for that and secured the cylinder head in such a way that all around the same amount of play between head and cylinder was measured with feeler gauges
After that no more problems 🤗