Just what the heck is a CJ750, anyway?
The CJ story begins in prewar Germany where BMW was building the last of its sidevalve bikes, the R71. Prior to the German invasion, the Soviets were already building copies of the R71, initially called the M71 and later the M72. Following the invasion, production was shifted from Moscow to Irbit (IMZ) in the Ural mountains where thousands were produced during and after the war. A second plant opened in Kiev (KMZ).

With technical support from the USSR, CJ750 production commenced in Nanchang in the late fifties. (Various sources cite dates ranging from 1957 to 1961.)

Today's CJ750 M1 is a copy of the original M72 right down to the 6V electrical system and other quaint features. The M1M is a slightly modernized version with a proper distributor, 12V electrical system and electric starter while the M1S is an OHV machine. The latter two models are equipped with reverse gearboxes.

The CJ is NOT a replica of the R71. It's a copy of the M72 which was a knock-off of the R71. The word replica isn't applicable.

The Chineseness of the CJ is its most intriguing quality. The detailing on my bikes emphasizes it rather than trying to conceal it.


Stephen Wiggins at Ural Australia sent this additional information regarding the Soviet bikes:

The M in M72 stands for Mototsikl which equates to the German R for Rad as in Motorrad. There were two plants to build the M72, one in Moscow and one in Leningrad (St. Petersburg). The Moscow plant moved to Irbit and the Leningrad plant to Gorky (Nizhny Novogorod). Production commenced in 1941 but due to war chaos and difficulties in obtaining supplies no bikes were completed until 1942. All sidecar bodies and chassis were built in Gorky near the GAZ factory until 1956.

In 1957 military production was shifted to Kiev. At the same time the Gorky plant was closed and tooling was offered to the Chinese. It is probable that plans for the K750 had been finalised and transfer of the now obsolescent M72 line could go ahead. The Chinese have admitted that it took them until 1961 to build complete motorcycles.

It is often forgotten that the Chinese were building a small number of Zundapp KS600-inspired bikes prior to the transfer of the M72 technology.

Also, despite what many people assert, the R71 was never built in great numbers and was not an official Wehrmacht bike. In fact the M71 was an appalling military bike until the changes brought in for the M72 in 1942. That being higher mudguards, dual clutch plates, 4.62 final drive and frame reinforcements. In reality the M72 is an improved military version of the civilian R71.

Another point to note is that the R71 is not really related to the R75 other than being made by BMW. The R75 is more closely related to the Zundapp KS750 than to any earlier BMW. In competition to build the Wehrmacht's bikes, BMW offered the R71 which they viewed as an improved R12, and Zundapp the KS750. So impressed were the Wehrmacht with the KS750, they wanted BMW to also build it. The R75 is the face-saving compromise that BMW developed.

As to what the M in M72 stands for - the myth that it stands for Molotov probably derives from the fact that the K in AK-47 stands for Kalashnikov, the designer. However, General Kalashnikov was a highly decorated officer, Hero of the Soviet Union, and a soldier NOT a politician. Stalin would never have allowed a model number to commemorate any potential political threat. If the M stood for Moscow then logic would dictate that the Leningrad plant would be building L71s and L72s, Irbit I72s, Gorky G72s and Kiev K72s. The K750 series may be the only example of this. The M in the MV series clearly stands for Motorcycle Army. Ural continued with the M designation all the way through to the M67 (and prototypes) until the adoption of the GOSTandart numerical identifying system used by ALL Soviet manufacturers.

References:

Origins of the Just Pre-WWII Soviet Motorcycles by P. J. Ballard, Feb 2002


M72 Origins Molotov/Ribbentrop

Historie der M72 und ihrer Nachfolger. Mit der BMW R71 fand die Entwicklung seitengesteuerter Tourenmaschinen ihren H_hepunkt und zugleich Abschluss. Die Geschichte der R 71 setzte sich aber in Russland fort. Eine Ver_ffentlichung der Motorrad-Classic Heft 2/2000

VON J.PEVSNER UND R. RODENKIRCHEN; FOTOS: PEVSNER, RODENKIRCHENI M. MOESCH


Personal conversations with Irbitski.

Even in these sources there are contradictions, though mostly over dates. For example the M72 was first assembled in Kiev in 1951 and more and more of the motorcycle was manufactured there until the introduction of the M72-N in 1956 which was completely made in Kiev, including the sidecar. At what point do you determine the M72 to be made in Kiev? 25%, 50% or 75%? Differing people take a differing viewpoint.


   What's what?

We often use different terms to refer to the same things which leads to some confusion, especially if you're new to the CJ thing. Here are some basics:

SV - Sidevalve engine, aka a flathead or flattie. All M1s and M1Ms have sidevalve engines.

M1 - 6V, 22hp 746cc sidevalve. This is as true as you can get to the original R71 or M72 predecessors.

M1M - 12V, 24hp 746cc sidevalve. Easily recognized by the external distributor on the forward, left side of the engine.

M1S - aka the Super, 12V, 32hp 746cc overhead valve engine.

OHV - Overhead valve engine. All M1S (Supers) have 12V, 32hp 746cc OHV engines.

R71 - BMW sidevalve bike from the late thirties that was copied by the Soviets throughout and after WWII.

M72 - (Originally the M71) The Soviet designation for their R71 copy. The CJ M1 is based on this machine.

650cc & 950cc OHV CJ engines also made but they are very rare. Equally rare is the 6V OHV engine.