ADLER motorcycles

"Adler" is the German word for "Eagle".
The MB 250 was one of Adler's most popular models (11,000 units were built between 1954 and 1956).
Two colour schemes were offered: Polychromatic Green, and Black.
The 247cc bike had a modern twin cylinder two-stroke powerplant that had some influence on early Japanese motorcycle engine design.
The company had some success in the area of competition as well, especially in endurance racing, and won many races with air and water-cooled versions of their 247cc street racers. Some all-terrain bikes like the Adler "Sixdays" were built up to 1957.

Adler was acquired by electrical giant Grundig in 1957, and motorcycle production ceased in favour of office equipment, notably typewriters.

1956 Adler MB 250
Aquired in October 2006 from the previous owner in Sydney, this bike is in very good condition for its age. It had been in storage since 1995. The coils have been replaced with 6V BMW coils and mounted under the tank. The exhaust mufflers are non standard, but seem to work well. The rocking-pedal footchange has been replaced with a normal type lever. It is a great little (16 inch wheels!) bike to ride, and very comfortable sitting on about 85km/hr, and has no problems keeping up with modern traffic around Canberra.

Specifications:
Manufacturer: Adlerwerke (Heinrich Kleyer AG), Frankfurt am Main
Australian Distributor: Mayfair Motors, Melbourne, Victoria.
Engine (No: 308154): 
Adler 247 c.c. (54 x 54mm) twin-cylinder two-stroke. Flat-crown, diecast aluminium alloy pistons. Double row roller big end bearings; mainshaft supported by three roller bearings. Separate cylinder barrels with detachable light-alloy cylinder heads. Compression ratio, 5.7 to 1. Petroil lubrication.
Claimed output. 16 b.h.p.;
Bing 1/22 carburetter enclosed by quickly detachable alloy cover; rubber connection to air filter, with strangler, fed through intake silencer in rear mudguard.
Electrical Equipment:  Bosch coil ignition, with 6-v. 6-a.h. battery in battery case on left of machine, charged by engine-speed dynamo fully enclosed in alloy engine case; compensated voltage control: Bosch 6 1/4-in. head lamp with double-filament main bulb; parking light; reflector adjusting switch; ignition warning light and neutral indicating light; tail lamp with stoplight; headlamp socket for external inspection lamp; electric horn built into battery case.

Gearbox and drive:  Adler four-Speed Gearbox in the engine block, positive-stop rocking-pedal footchange; ratios, 6.3, 7.6, 10.5 and 19.26 to 1; primary drive by helical gears; final drive by 5/8 x 1/4-inch roller chain enclosed in pressed-steel case; Multi-plate, engine-speed clutch running in oil.
Chassis (No: 308154): 
Double tubular brazed frame with great lateral rigidity with sidecar adapter.
Suspension: Leading bottom-link front fork, hydraulically damped.
Plunger-type rear springing, hydraulically damped and adjustable for load.
Tyres:  3.25 x 16in front and rear.
Front and rear wheels are interchangeable.
Full width drum brakes 180 mm front and rear.
Fuel tank:  approx. 15 ltr, rubber mounted, with rubber knee grips
Toolbox: Lockable toolbox mounted on RHS rear frame. Tyre pump mounted on LHS rear frame.
Finish: Polychromatic light green and chrome with light-metal parts in dull sheen. Alternatively black and chrome.
Gross weight: 135 kg