DKW RT125: history, specs, pictures

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The famous DKW RT 125 of 1950
MZ RT 125

The RT 125 was a model of two-stroke motorcycle made by DKW in Zschopau in the 1930s, Industrieverband Fahrzeugbau and MZ in the 1950s and early 1960s, and DKW in Ingolstadt in the 1950s and 1960s. "RT" stands for "Reichstyp" or "National Model".

In the 1930s DKW pioneered the Schnurle two-stroke loop scavenging process to dispense with the use of a deflector piston and improve efficiency of the combustion chamber. DKW also developed a highly efficient arrangement of transfer ports. These two features were included in the RT 125 to great commercial advantage. Competitor companies such as Adler and TWN copied the adoption of flat-topped pistons and strove to develop equally transfer port arrangements without infringing DKW's patent.

The RT 125 is probably the most copied motorcycle of all time. After World War II the Soviet Union took plans, tooling and even several dozen personnel as war reparations to MMZ in Moscow (later transferred to MMVZ and SMZ) and to a factory in Kovrov, and produced copies of the RT125 as the M1A Moskva and K-125 respectively. WFM of Poland made a modified version of the RT125 (under SHL 125 and Sokół 125 brands), developed into 125/175 ccm family motorcycles, produced until 1985. RT 125 plans were also taken to the United Kingdom where they became the basis of the BSA Bantam, and to the USA where they formed the basis of the Harley-Davidson "Hummer". Later Yamaha in Japan copied the RT 125 as the basis of their first motorcycle, the Yamaha YA-1.

Since 2000 MZ Motorrad- und Zweiradwerk GmbH has used RT 125 to refer to an entirely new model of four stroke motorcycle. This motorcycle features a 125cc liquid cooled DOHC single cylinder engine. It is claimed to be the most powerful commercially produced four stroke 125cc engine in the world, developing 15 bhp.

External links[edit | edit source]

2001-07-31 DKW RT 125 im Audi-Museum 02.jpg
Also called RT1252H, RT 125 2H, RT1252, RT 125 2, RT125E, RT 125 E, RT 125
Production 1952 - 1973
Class Road
single cylinder, two-stroke
Bore / Stroke 54.0mm x 54.0mm
Top Speed 75 mph (120 km/h)
Horsepower 16.63 HP (12.4 KW) @ 7500RPM
Fuel System carburetor
Ignition magneto
Transmission Gear box: 6-speed

Final Drive: chain

Clutch: wet multiplate
Suspension Front: telescopic fork
Rear: none
Brakes Front: expanding brake
Rear: expanding brake
Front Tire 2.75-17
Rear Tire 3.00-17
Length 77.13 inches (1959 mm)
Width 25.98 inches (660 mm)
Height 25.98 inches (660 mm)
Weight 189.6 pounds (86.0 Kg) (dry), 108.0 kg (wet)
Fuel Capacity 2.77 Gallon (10.50 Liters)
Manuals Service Manual

The DKW RT125E was a single cylinder, two-stroke Road motorcycle produced by DKW between 1952 and 1973. It could reach a top speed of 75 mph (120 km/h). Claimed horsepower was 16.63 HP (12.4 KW) @ 7500 RPM.

Engine[edit | edit source]

The engine was a air cooled single cylinder, two-stroke. A 54.0mm bore x 54.0mm stroke result in a displacement of just 124.0 cubic centimeters. Fuel was supplied via a port control.

Drive[edit | edit source]

The bike has a 6-speed transmission. Power was moderated via the wet multiplate.

Chassis[edit | edit source]

It came with a 2.75-17 front tire and a 3.00-17 rear tire. Stopping was achieved via expanding brake in the front and a expanding brake in the rear. The front suspension was a telescopic fork while the rear was equipped with a none. The RT125E was fitted with a 2.77 Gallon (10.50 Liters) fuel tank. The bike weighed just 189.6 pounds (86.0 Kg).

In Media[edit | edit source]