In common opinion the Russian boxer bikes are copies of the German BMW motorcycle, which Russians took over as war reparations. It is not however the full story...
The history of those bikes starts in 1939, when the infamous Treaty of Non-Aggression between Germany and the Soviet Union, was signed by the Soviet foreign minister Vyacheslav Molotov and the German foreign minister Joachim von Ribbentrop. Despite the political aspect, the treaty also contained a huge trade agreement. In return for a food supply, the Germans gave Russia great technological support including BMW R-71 motorcycles. To be precise, the Russians gained the vehicles only, without technical documentation. When in 1940 the army sent a demand for large numbers of those machines, they had to create the documentation from scratch. Advanced German technologies weren't known before in the Soviet Union. Frames made from variable diameter tubes, complicated, light alloy engine and gearbox case castings, telescopic fork suspensions were a great challenge. For that reason the production was located in several factories across the country. Engines were built by ZIS factory, gearboxes were made by KIM, side-cars came form GAZ etc. Final assembly began in August 1941 in Moskovski Vielozavod (Moscow Bicycle Factory).
When Hitler broke the treaty, in June the German army invaded Russia. In November Moskovski Vielozavod (by that time named Moskovski Motozavod (Moscow Motorcycle Factory) was evacuated to a little town called Irbit in the Ural mountains. At a former brewery the new Irbicki Motozavod (Irbit Motorcycle Factory), IMZ was formed.
Dark and damp old buildings weren't suitable for the new purpose. Employees suffered many illnesses, the factory was trying to function without electricity, using a generator powered by a motorcycle engine. Because of the shortage of aluminium, engine and gearbox cases were made of cast iron. Despite all the difficulties they managed to start the production in February 1942. By the end of the war 9799 units were delivered to the army.
In the spring 1942 the construction of new production sheds started. The production of 15.000 units per year was planned, however this goal wasn't achieved.
After the war a new expansion plan was instigated. The M-72 improvement began. In 1946 a dual plate clutch was introduced and the main gear ratio was changed from 3.89 to 4.62. In 1948 the frame was strengthened and the engine gained a new air filter. In 1950 the factory celebrated production of it's 30,000^th bike.
 
From 1951 the factory in Kiev – KMZ (Kiev Motorcycle Factory) also began production of the M-72.

IMZ M-72M

In it's primal version the M-72 was built until 1956, when it's successor, the M-72M was introduced. In 1953 export began and the next year they gained permission to sell the motorcycles to the civilian market. The production of the military bikes was passed to the factory in Kiev.
The new machine was given improved brakes, stronger frame, new front mudguard and rear light. The side-car suspension was also modified by the introduction of a torsion bar.
In 1961 this model was replaced by the M-61 with an overhead valve engine.

M-52

The M-52 was the first mass production model with an overhead valve engine. It appeared as a prototype in 1954 and the production began in 1956. It was designed for on-road use. The side-car was optional. Along with the all-new 494 cc engine the bike had new front suspension and brakes with light alloy drums. A sport version – M52S was also built. In 1959 the appearance of this model changed. It now looked similar to the later M-61.
678 were built by 1961.
It is worth mentioning that the first overhead engine powered bikes were built in 1945. They were road-race machines M-75 (1945-1951), M-75M (1951-1954) and M-77 (1954-1959). No more than 10-20 units per year were made.

M-61

The M-61 was introduced in 1961 as the successor for the M-72M.
Unlike in the K-750 built in Kiev, engineers in Irbit left the frame and the suspension unchanged, focusing on the new 649 cc overhead valve engine.

M-62 Ural

The M-62 was a transition between M-61 and M-63. The main, noticeable difference was a deeper front mudguard.
For the first time the name 'Ural' was used.

M-63 Ural

The production of the M-63 Ural started in 1965. It had rear suspension with a swing arm instead of sliders and a new shaped fuel tank. The engine and the gearbox remained unchanged.
This model was built until 1970.

M-66 Ural

The M-66 was a modernised version of the M-63. With the export markets in mind a new colour schemes were introduced. The bike received indicators and new shape of handlebar. In the engine a full-flow oil filter and a dry, paper element air filter was used. The frame and front suspension was also improved.
This model was produced from 1970 to 1975.

M-67-36 Ural

The most important novelty in the M-67 was an all new 12 volt electrical system with an alternator instead of dynamo. A new head light and dashboard was also introduced.
A noticeable difference was the modified rear suspension and a frame that allowed using a single or double saddle. The front brake gained double expander cam which greatly improved braking efficiency.
In 1976 the engine output rose from 32 to 36 h.p. and the motorcycle was called Ural M-76-36.

M-72N

Production of the M-72 in the factory in Kiev began in 1951.
The first modification was introduced in 1957. The M-72N differed from it's predecessor by the leading link type front suspension and light alloy brake drums. New, adjustable taper roller bearings and stronger spokes were used. Since the bike was available on the civilian market a mirror and front fairing become optional equipment. The wheel base rose by 50 mm to 1450 mm.
This model was probably designed by IMZ engineers (hence the badge on this lovely illustration).

K-750

In 1958 production of the famous K-750 began. Unlike M-61 from IMZ, designers from Kiev left the old, side-valve engine and focused on improving the frame and suspension.
The sliders of the rear suspension were replaced by a double swing arm with coil springs and hydraulic shock absorbers. In the side-car the torsion bar was replaced by a swing arm supported by a coil spring and shock absorber, the same as used in the rear bike suspension. That greatly improved the side-car clearance.
Engine compression ratio grew from 5,5 to 6,0 which increased the output from 22 to 26 h.p. Gradually the motorcycle was improved by gaining modified engine heads, front casing covering the ignition, handlebar with handles pointing outwards rather than inwards and finally much simpler front suspension. In 1964 the bike become K-750M. The military equivalent of this model was MW-750, described further down on this page. The civilian version however never had the gearbox with reverse.
Between 1958 and 1976 292,781 examples of this fabulous machine were made in various versions.

K-650 Dniepr

The first motorcycle with the overhead valve engine from Kiev was launched in 1967. It was K-650 Dniepr. This model was built in parallel with the K-750 until 1977. 36,963 units were made.

MT-9 Dniepr

The next model was the Dniepr MT-9. It was introduced in 1971 as an addition to the range. The bike was equipped with a gearbox that had the reverse gear. By 1976 189,463 were built.

MT-10 Dniepr

Dniepr MT-10 gained a new frame, similar to the one used in Ural M-67, new fuel tank and 12 volt electrical system. It was made from 1973. 141,839 were built.

MT-10-36 Dniepr

The real successor to the K-650 and MT-9 models however, was the MT-10-36. A new shape fuel tank taken from the MT-10 and a one-piece saddle was combined with the old reliable frame allowing the use of the gearbox with reverse. The electrical system was 12 volt with an alternator, indicators and a new headlight. This model was built from 1976 to 1984.

12 Dniepr

Because of continued demand for the bikes with side-valve engines the factory introduced the model Dniepr 12. It was specially designed for use in difficult conditions, on unpaved roads or even off-road. The side-valve engine was more suitable for that purpose because of the maximum torque achieved at lower rpm. The bike looked like the MT-10-36 but retained a 6 volt electrical system and had a shaft propelled side-car wheel. A special reduction gear allowing 36% of torque onto the side-car wheel and 64% onto the rear wheel improved driveability of the vehicle.
Dniepr 12 was the last model with the old side-valve engine. Around 200.000 were built.

MT-11

Dniepr MT-11 was the successor of the MT-10-36. It was available either with one-piece double seat or two separate saddles. There were two engines to choose from. One could still run on low-octane petrol LO 72. The other one, offered mainly for export had higher compression ratio, requiring better fuel LO 93 (KMZ 3.8-155.6). The engine was equipped with an air filter with replaceable paper cartridge. Braking was improved by using an additional brake on the side-car wheel, working in conjunction with the rear brake. Between 1983 and 2005 they built 708,792 units.

MT-16 (KM3-8.9226)

The Dniepr 16 was built in two versions: KM3-8.922-02 and KM3-8.9226. Both were designed for use with a side-car The vehicle was driven by a gearbox with reverse, driving both rear and side wheels. The difference was in the engine with a compression ratio increased from 7,0 to 8,5:1. The bike was available with a one-piece double or two separate saddles.

MT-16 (KM308.157-01)

KM308.157-01 Dniepr was based on the Dniepr-11 and designed for use without the side-car. It had smaller wheels with 3,50x18 tyres, 'faster' main gear ratio (3,89:1), softer front suspension, different front mudguard, safety bars etc. The reverse gear was simply factory blocked and there was warning in the manual about unblocking it.

K-750W

When in 1954 permission to sell the motorbikes to the civilian market was gained from the government, whole production of military versions was passed to the factory in Kiev. The first model designed specifically for the army was the K-750W a modified civilian K-750. This machine differed mainly by having military equipment added: a brackets for a machine gun, ammo boxes, additional externally mounted box, mountings for shovel, axe, tools etc.
K-750Ws were used by the Polish army in the 1960's and 70's.
 
Below is the direct translation of the description of this motorcycle from the manual by the Polish Ministry of Defence of 1966.

"The K-750W (fig. 1 and 2) is designed as a heavy duty motorcycle with a side-car, powered by 750 cc engine.
In comparison to the previous model M-72 it has much better performance, specially in technical and economy specifications.
The motorcycle consist of: power unit – engine with it's equipment, transmission, suspension, frame and electrical system.
The motorcycle is equipped with a set of spare parts, tools and devices and has attachments for special equipment and a removable metal box for auxiliaries.
K-750 motorcycle has a tubular frame. The front suspension is of a leading link type and rear suspension is a swing arm type. The engine with the clutch, gearbox, air filter, carburettors, dynamo and the ignition is mounted in the frame at three points: two at the bottom and one at the top.
The gearbox is a four speed with hand (on the right hand side) and foot (on the left hand side) levers. From the gearbox the drive is transmitted into the final-drive gear via the propeller shaft. The final-drive is located at the rear wheel hub, mounted between the rear suspension arms.
The front end of the suspension arm is pivoted in the frame and the rear end is suspended on two coil springs with two hydraulic shock absorbers.
The rear brake is connected to the foot lever on the right hand side.
The front suspension has two short swing arms with two horizontal shock absorbers. The shock absorbers are jointed to the steering head of the frame. There are two coil springs located inside the fork tubes. The fork can be turned by 45° each way. At the top of the fork there is a friction type adjustable steering damper.
The front brake is connected to the hand lever located on the right hand side of the handlebar.
The handlebar is mounted on the top end of the fork connection bar. On the left hand side there are: clutch lever, ignition adjuster lever, light and horn switches. On the right hand side there are: throttle twistgrip, and a hand brake lever.
The headlight is mounted on brackets at the top end of the fork. The headlight case contains the speedometer, warning light, main switch and the ignition switch.
The fuel tank is mounted on top of the frame. On top of the tank is a tool compartment.
Driver and passenger saddles are unified. The driver saddle is mounted to the frame and the passenger saddle to the rear mudguard. They are sprung by adjustable rubber bushes.
The wheels are interchangeable and easy to remove. They have adjustable taper roller bearings, light alloy brake drums and short spokes.
The single seat side-car consist of a frame and the body. The tubular frame is connected to the motorcycle at four points: two pivoted arms at the bottom and two adjustable rods at the top. The wheel is suspended by a swing arm with a coil spring and hydraulic shock absorber, the same as in the rear suspension.
At the back of the side-car, behind the seat there is a luggage compartment. The spare wheel is mounted on the rear upper panel. The side-car has a number of brackets and mountings for special equipment."
 
Fig. 1 and 2. K-750W – an early version with front swing arm
Fig. 10. A modified engine head
Fig. 77. Head lamp introduced in later K-750W models
Fig. 32. Ignition system with automatic, centrifugal ignition advance adjuster introduced in 1963
 
(illustrations from the manual by the Polish Ministry of Defence 1966)

MW-750

Externally almost identical with the last series of K-750W models the MW-750 gained side-car wheel drive. Initially it was equipped with the gearbox type 6204 with the differential lock but without reverse which became a standard feature in later models.

MW-750M

The motorbikes built for the army evolved in the same way as those built for civilians. MW-750M was basically a military version of the Dniepr 12. MT8204 gearbox had the reverse gear and the differential lock has been replaced with a reduction gear. A fuel tank and part of the electrical system from the Dniepr 12 was also used (except of the indicators and the head lamp). From 1975 a stronger rear shock absorbers were used.

MW-650

Motorcycles with overhead valve engines were also delivered to the army. MW-650 had a MT801 engine, detuned to allow the use of low-octane petrol. Initially it was equipped with a dynamo and later also with an alternator. The gearbox type MT8204 was identical to the MW-750M.
Braking was improved by the use of double expander cam on the front and additional brake on the side-car wheel, working in conjunction with the rear brake.
Front and rear lights were identical with the civilian MT-10.
This model was modified the same way as civilian models and became MW-650M and later MW-650M1.
Between 1968 and 1991 the factory built 6,687 examples of all versions (MW-650, MW-650M and MW-650M1).