MZ: Forerunner of All of The Japanese Two-Stroke Successes

Before looking at the development of the MZ marque we should take a step backwards to before the 1939 hostilities and into those early days of motorcycle development, in fact to 1906. The Danish entrepreneur Jorgen Skafte Rasmussen bought an empty textile mill in the small Saxony town called Zschopau and started making steam valve equipment. In 1917 he revealed to the world his DampfKraftWagen (Steam Powered Car) and the trademark DKW became known to the world. Initially the original production of steam engines. Later, the company focused on the manufacture of motorcycles and eventually the production of small cars. 

But the market for the steam engine offered no great potential for new developments. Therefore Rasmussen gave up on this technology again in 1918. Nevertheless, the founder of DKW didn't give up on his goal of producing vehicles himself. Picture above: the Steam Car (DampfKraftWagen) of  Jorgen Rasmussen.

In 1920 he started producing motor-assisted bicycles and by 1929 they were producing 60,000 motorcycles a year, making them the world’s largest motorcycle producer. Production continued until 1932 when the four factories of Audi, DKW, Horsch and Wanderer merge during the great depression to form the Auto Union. The interlocking rings in the badge remain in use today on Audi cars. Each ring representing one of the four firms of the union.

In 1930 DKW revealed the RT125 model, fitted with a new motor designed by Hermann Weber: a humble single cylinder; three speed unit construction engine, that subsequently went on to achieve automotive greatness. this engine had a capacity of 125cc. Picture: 125 cc, 4¾ bhp, 66 kg, 75 kph. The ideas incorporated in this machine were to influence the design of light bikes for decades to come, with its foot operated 3 speed gearbox, compact dynamo and lightweight rubber cushioned tubular frame.

After the end of hostilities in 1945, the occupying Soviet forces nationalised the Zschopau factory, erasing the DKW name from the Chemnitz register of companies. Under the threat of prosecution, the former DKW directors fled westward to set up production once more in Ingolstadt, Bavaria. Picture: Jorgen Skafte Rasmussen and his wife Theresia 1904 

The Zschopau factory resumed production of the RT125, only one model and the shaft drive twin cylinder BK 350 models under the new name of IFA (Industrieverwaltung Fahrzeugbau) and in 1956 the company was renamed to Motorradwerk Zschopau, or MZ for short.

The RT 125 design was taken as war reparations and put into production, around the world. If ever there was an award for the most influential motorcycle ever built, the RT125 must have a claim to that title, being the machine that helped put the world back to work. This design spawned Royal Enfield’s Flying Flea and then the Ensign; BSA’s beloved Bantam, the Harley-Davidson Hummer, the Minsk 125, the Polish Sokół 125, SHL 125, the Russian M1A Moskva, a model from India and even the 1955 Yamaha YA-1. Picture:125, the Russian M1A Moskva.

1945-49 Royal Enfield RE125 Flying Flea125cc.	1955 Royal Enfield 148cc Ensign	1948–1971 BSA Bantam D1	1948 The Model 125 or S-125 was introduced by Harley-Davidson .
1947 Polish Sokół 125cc. Prototype for the new design was the DKW RT 125.	India - 1962 Rajdoot Excel T 175cc.  A licensed copy of SHL’s M11 with minor changes	1947 SHL M02 125. The first Polish motorcycle mass-produced after the war. (M04 Shown)	Yamaha Motor's first motorcycle the YA-1 based on the DKW RT125

Faced with having to build a new factory in Ingolstadt, its old Zschopau base having ended up in the newly established East Germany at the end of 39/45 war, DKW took time to revive the racing programme that had enjoyed such success in the inter-war period. In the long-gone days when single cylinder Manx Nortons were still chasing, but rarely beating, the Italian 'fours' of Gilera and MV, enthusiasts for two-stroke engines were looked upon as the weirdos of motorcycle racing.

In the meantime, enthusiastic privateers flew the DKW flag with assistance from the factory, this collaboration being exemplified by the machine shown in the picture here. Helga Steudel at a race in 1963 on an RE 125  

The MZ factory itself was scarcely established at that time. It was in the pre-war home of DKW, but with the partition of  East and West Germany in 1946, DKW had gone to the 'west' so to speak, and the old plant had become - Motorradwerk Zschopau (Motorcycle works at Zschopau). As a matter of interest, DKW relocated  at Ingolstadt, West Germany, in 1949, and produced a most interesting three cylinder, two-stroke racer which, by 1956, was the most potent, if not, the most reliable, 350cc machine in classic  racing. Picture: The original DKW 3-cylinder two-stroke beast. (click the image to visit the Vintagent web site.

 

 

Two-stroke racing machines were briefly competitive just before the 1939/45 war from the challenge, which  bordered on dominance, of Germany's DKW factory with supercharged engines. It was firmly believed however that the 'Deek' success was due entirely to the vantage of forced induction; and with  the FIM's ban on blowers in 1946, most 'experts' reverted to the belief that unblown two-strokes, which theoretically should be twice as efficient as a  four-stroke, were still impossible to  consider as a serious practical threat. Up to that time the best figure for a two-stroke was Helmut Gorg's 130 b.h.p./litre in 1956 when he got 45 b.h.p. at 9,700 r.p.m. from the 349 c.c. three-cylinder D.K.W. with piston-controlled ports.

So while the majority of highly qualified racing engineers continued to dis-regard them, a few, mostly in Germany set about proving the 'theory' of a two-stroke engine being able to produce 'twice' the power of an equivalent capacity four-stroke without the aid of a  supercharger! Famed among them and unquestionably the leading pioneer in this field of development, was East Germany's Walter Kaaden. 

Hailing from Chemnitz, Kaaden built and raced  his own two-stroke machines with disc-valve induction and the success of these  led to his appointment as development engineer at MZ in 1952. Click the photo to visit the Kaaden page.

Walter Kaaden's first effort at MZ and built in 1953, was an air-cooled, 125cc single cylinder engine producing a modest 9 bhp at 7800 rpm. Development over the next twelve months saw this increased to 13 bhp at 8000 rpm - adequately showing the point he was determined to prove; that accurately timed induction (by disc-valve) was vastly more efficient than conventional cylinder ports where, with long- timing, power was lost from the inevitability of fuel being blown back through the carburettor.'

Part of this development work included the testing of many different exhaust pipes with variations of shape and size;  the aim being to discover a shape that would create a depression in the pipe  during the transfer stage of induction to cause a reverse pressure wave that would  prevent the next incoming charge escaping through the exhaust pipe while the ports  were still open.

Major breakthrough with this work came in 1955 when the first 'modern' style exhaust system appeared with a baffled tail pipe. By preventing this fuel  loss, power was increased to 15 bhp at 9000. At this time too the Kaaden-Degner team had also produced a 250cc 'twin. How? - by the simple expedient of grafting two 125cc top-half assemblies on to a common crankcase; with the power output being- taken by gears from the central crankshaft coupling.

This simple expedient, however, did not provide an instant 30 bhp 250! As power increased, so the revs soared too and fast-moving components began breaking  - bearings shattered, magnetos burst, and rods snapped and the powerband was reduced.

MZ and the Race Track. Throughout the 1960s MZ developed their lightweight two-stroke motor by competing at the highest levels in road racing and International Six Day Trials. Development was led by their chief engineer Walter Kaaden, who's experience had been formed in the factories of rocket based propulsion and now considered to be the father of the modern two-stroke engine.

Kaden had also employed a young and very capable, qualified engineer named Ernst Degner to work with him in the development of all aspects of the two-stroke development. During this early period Kaaden was responsible for perfecting disc valve technology, expansion chamber development and exhaust induction supercharging techniques that made the early 1960s MZ 125 and 250 machines such formidable opponents on the track. With these two engineers working on these developments, they change the whole face of two-stroke racing, forcing other manufacturers to develop their own two-stroke race machines in order to compete.

For 1956, the 125 cc gave 16 bhp, weighed 80 kg 1 and could attain a speed of 155 kph. Yet another leap forward in the construction of Kaaden's 2 stroke racing engines and this by making systematic use of the vibration and flow processes. Also the opportunities offered by a plate type rotary valve induction. So in this year 1956, modifications included needle roller bearing small-ends, battery ignition and a six-speed gearbox to help the narrowing power band which then  gave 16.5 bhp at 9200 rpm from the 125.  The 250 produced about 30 horse power.  

During this time, MZ had not raced outside its own country, but showed strength in 1957 at two international  meetings at Zandvoort, Holland, and  Nuremburg, West Germany, where  Degner led his team-mates, Fugner and  Musial, to 1-2-3 victories in the 125cc  class at both events.

After contesting the world championships for the first time in 1958, M2 re- appeared the following year and gave 'foreign' riders the opportunity of racing their machines. First of these was our own Derek Minter who showed that he could ride something other than a 500cc Norton at Brands I-latch, by bringing the 125cc two-stoke into fifth place at the Dutch TT and fourth in Belgium.

Greatest success for MZ in 1959 came from the late Gary Hocking who, at his first attempt on a two-stroke, beat Carlo Ubbiali (MV) and Geoff Duke (Benelli) in the 250 Swedish GP. Degner (MZ) was fourth.

Hocking then showed that this was no fluky ride by winning the 250cc Ulster GP by 25 seconds from Mike Hailwood (Mondial) at a record 89.26 mph - with a lap record of 91.12 mph.  The threat from Hocking by winning these two races put Count Agusta into a spin, for the next event was the Italian GP - and he couldn't have an MZ rider beating his MVs at Monza - so he bought Hocking! Picture right: Gary Hocking

But he only bought the rider and not the bike - for Degner (MZ) beat Ubbiali (MV) to win the 125cc race in a wheel-to- wheel finish with Taveri (Ducati) and Minter (MZ) less than a second behind!

But the 'Count' had only bought the rider and not the bike - for Degner (MZ) beat Ubbiali (MV) to win the 125cc race in a wheel-to-wheel finish with Taveri (Ducati) and Minter (MZ) less than a second behind!

Degner, riding brilliantly, certainly put MZ on the map that day, for although Ubbiali beat him by less than a length in the 250cc race at 107.52 mph, the MZ was then in its infancy against the thoroughly developed double overhead camshaft MV. From that point on, Kaaden put most of his effort into improving the 250cc twin which, still air-cooled, appeared again in 1960 with a power level of some 42 bhp.

Another interesting feature was that after Minter and Hocking had raced it in  1959; when the handling was not all that it might have been, the 1960 version was fitted with Norton 'Road-holder' forks! These were not copied, but were an actual Manx Norton front fork which came into MZ's hands after the Ulster GP. It appears, from idle paddock chatter, that a 125cc MZ  engine featured in a swap!

Having developed highly competitive machines, MZ's greater problem was with finding capable riders. Even in those days, when starting money was a pittance compared with today, MZ couldn't pay anything to foreigners - for they had no Western currency and East German cash, on the West side of the border, was worthless. MZ two stroke racing team 1959 Mike Hailwood Walter Kaaden Ernst Degner.

John Hempleman MZ 125cc 1960 Ultra-Lightweight TT

However, this failed to deter New Zealanders, John Hempleman and Alan Shepherd who, despite finishing fourth and fifth in the 125cc lsle of Man TT - behind the MV trio of Ubbiali, Hocking  and Taveri - were ahead of the entire  Honda contingent. Revenge for MZ came at the Belgian GP  where on the ultra-fast Spa circuit, Degner led Hempleman home by five seconds at 100.12 mph with Ubbiali, Spaggiari, and Hocking chasing them in.

Alan Shepherd (MZ) 1964 Lightweight TT

OF ALL THE PEOPLE lucky enough to have escaped from behind the 'iron-curtain' of Eastern-Europe, none can have influenced a world industry more than Ernst Degner. When he fled from East Germany-in  1961, he brought with him from MZ the  formula for modern racing two-stroke  design  information which he passed  on to Suzuki and on which all future Japanese  two-stroke engines were based.

Although Degner was an accomplished engineer with MZ, he was also its star rider. He was  leading the 125cc world championship in 1961 when, with just the final race (the  Argentine GP), to go, he chose that moment with the title in his grasp to make his most vital dash for freedom.

This fact cost him, and particularly MZ, their only close approach to  ever winning a world title, but this was of no consequence to Degner,  as his target was to make a bid for his life which also secured the safety of his wife and two sons.

But overlooking the cloak-and-dagger  stuff, Degner's defection was nonetheless  extremely costly for the MZ company, manufacturers of the most deserving machine never to win a world title, for they had discovered the 'secret' of two-stroke engine efficiency, the control of the resonant forces of gas induction and exhaust.

It was this basic formula which Degner took to Japan and started the subsequent development of all oriental designs and their future dominant racing success.

Never regarded as a serious contender (British manufacturers held a similar view  of the Italian four-stroke multis), two-stroke machines were seen as no more than cheap, commuter transport and to actually race a two-stroke was courting suicide from the probability rather than the possibility of being flung over the handlebars with the inevitability of sudden engine seizure!

Mike Hailwood on the 250cc MZ, East German GP 1964. Desperate to race in the 250cc class he persuaded MV to let him ride the MZ. He was leading the Redman Honda 4 and Phil Read Yamaha RD56 twin by 150 yards when the bike seized and he Mike ended up in hospital with severe concussion. MV banned any more 250cc racing whilst under contract to them.

After Degner's defection in 1961, MZ's most predominant 250cc riders were Alan Shepherd, Derek Woodman and, occasionally at the East German GP, Mike Hailwood where he invariably led the race until the machine failed - or, as he did on one particularly rapid occasion, fall  off!  

With its water-cooling and carburettors at  the side, the MZs were ten years ahead of  their time compared to Japanese race machines. Main picture shows the 250  MZ-twin while the inset photo below is of the 125  single cylinder MZ. The pictures were  taken 15 years ago!

So distinctive with its modern concept of water-cooling, rear facing exhausts and carburettors at the sides, the MZ was, by Japanese standards, ten years or more before its time. Indeed, all the various calculations which Professor Gordon Blair now works out in a few minutes for Yamaha on the Queens University, Belfast, computer, Kaaden was aware of more than 20 years ago. 

But that was before computers when all he had was al slide-rule, a pencil and the engineering ability to produce a most  remarkable racing machine.   

Shortage of high-grade metals became Kaaden's greatest problem. He once told me that had titanium, barilium and various other 'space-age' metals been available to him, the 250 MZ in 1965 could  have been producing over 70 bhp with  reliability! 

The chance of this work becoming possible came very close with British co-operation. MZ had talks with Velocette for this Birmingham company to market  MZ machines in this country. Having established a base at Hall Green, MZ had thoughts of being able to produce such a way-out racer - but time passed, nothing happened, Veloce closed  down, and MZ now are just a racing  memory.

MZ Album of Riders.

The Editor wishes to thank TT Race Pics and Bill Snelling for permission display to these pictures.           Click to Visit. 

Alan Shepherd (MZ) 1964 Lightweight TT	Alan Shepherd (MZ) at Signpost Corner; 1964 Lightweight TT	Alan Shepherd (MZ) at Quarter Bridge in the 1964 Junior TT	Derek Woodman (MZ) on Bray Hill, 1965 Ultra Lightweight TT	Derek Woodman (MZ) at Ballaugh Bridge; 1967 Junior TT	Eddie Crooks (MZ) 1960 Ultra Lightweight TT
Eddie Crooks (MZ) on Bray Hill, 1960 Ultra Lightweight TT	Eddie Crooks MZ 1960 Lightweight TT	Ernst Degner MZ 1958 Ultra-Lightweight TT 125cc	Ernst Degner on Ballanard Road 1959 Lightweight TT	Ernst Degner MZ 1959 Ultra-Lightweight TT	Ernst Degner (MZ) 1959 Ultra Lightweight Ulster Grand Prix
Gary Hocking (MZ 15) leads Mike Hailwood (Ducati). Positions reversed at the flag 1959 Ultra Lightweight Ulster Grand Prix	Mike Hailwood (Ducati) narrowly leads Gary Hocking (MZ) in the 1959 Ultra Lightweight Ulster Grand Prix. Mike held on to win	Gary Hocking, Mike Hailwood and Ernst Degner 1959 Ultra Lightweight Ulster Grand Prix	German Gunther Bartusch (MZ) 1970 Ultra Lightweight TT	Heinz Rosner (MZ) at Quarter Bridge; 1968 Lightweight TT	Horst Fugner (MZ) 1958 Ultra Lightweight TT
Horst Fugner (MZ) 1959 Ultra Lightweight TT	Jim Redman (Honda) and Alan Shepherd (MZ) in the winners enclosure 1964 Lightweight TT. Walter Kaaden far right in the picture	John Ringwood (MZ) 1969 Ultra Lightweight TT	Luigi Taveri (MZ) at Parkfield Corner 1959 Ultra Lightweight TT	Peter Williams (MZ) at Ramsey; 1971 Lightweight TT	Ralph Bryans (Honda) and Derek Woodman (MZ) 1967 Lightweight TT

The 50cc Baby MZ (Translated from the Dutch language

The baby from the Zschopau MZ racing stable. The 50cc from the MZ racing team. They brought it with them to Salzburg because they wanted to do some practice laps on the Autobahn circuit; but then they told us they wouldn't be able to get an entry visa for Barcelona either – so they left it under the tarpaulin. But we were allowed to see it, photograph it, and learn a few facts that might be of interest.

The 50cc MZ developed for the World Championship races is, all in all, nothing more than a scaled-down and, in most parts, "slimmed down" version of the successful 125cc single-cylinder engine, Crankcase, gearbox, and full circle crankshaft. The 1:2 geared stationary magneto (whose power requirement will probably be eliminated by a coil ignition) - all of this is based on the original parts of the 125cc. Picture: 1962 MZ 50cc Race machine.

But even with the chassis, one initially believes one is dealing with the larger engine, because, to the eye, one cannot immediately tell that the frame tubes are thinner walled, as are the upper tubes of the telescopic fork, the rear swingarm fork, and others.

The brakes (double brake at the front) are similar to those of the 125, only significantly modified on the inside; originally, smaller and lighter ones were planned, but they were not sufficient.

Stopping power, especially in view of the expected speed increases in this class, the large brakes are absolutely necessary, said Kaden, because you don't just want to be able to brake, you also want to be able to really slow the machine down. Of course, the tyre size currently used for the test runs (2.50-18) won't be enough: 

Avon had special tyres made for the MZ with 2.00 and 2.25-18 tires ready in Barcelona. But they waited in vain for MZ in Montjuich Park. The engine (apparently so insensitive that you can get by without a rev counter. You just let it rev, like Ted Mellor's once did with the 1939 T1-Benelli, until the note no longer gets higher) shows the typical MZ arrangement in terms of cylinder ribbing and rear-exited exhaust (original 125 exhaust system), only the head ribbing has been changed.

Stroke and bore, is almost standardised for this displacement size. 39x40 now. Power at the rear wheel over 10 hp. Despite numerous even heavier components, the prototype weighs no more than 55 kg, even with the heavier wheels! Ben.  

Some more information from a reader of the Classic 50 Racing Club site: Göran Kähler, The four colour photos are from Assen 2010 and are of Rainer Pommers ex-works 1962 MZ-RE 50cc. The black and white Motorrad photos are of the only time the 50cc babies came out in anger, two works MZ-RE 50 from the Sachsen Ring meeting, the 50cc East German GP. in 1962. They crossed the line in 8th & 9th position.

The air cooled MZ-RE 50cc

The water-cooled MZ-RE 50cc

Some comments in the pits were that what was missing from the development of the MZ 50 was that little bit of 'Degner' that completed the circle.  There was no more Gran Prix racing due to the slow performance. The second MZ 50 included a water-cooled cylinder, this was the difference of the two taking part. There would be no further development of a MZ 50cc machine as Simson were to develop/build 50cc machines.

When Degner joined Suzuki, what was his target and did he achieve it?  His main task was to help create a new 125 that had to make at least 22 horsepower if he was to receive his £10,000 reward (£200,000 in today’s money) and he succeeded in making a mirror-image copy of the MZ single with 24 horsepower, and the season was a triumph for Suzuki.

The little '50' scored Suzuki’s first-ever World Championship point at Barcelona in May 1962, then won the company’s first World Championship race at the Isle of Man, where Degner averaged a dizzying 71mph – faster than the Suzuki's factory’s 125 had managed just two years earlier.

It needed Ernst Degner's technical help

MZ 50cc Air-cooled Race Bike

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