MZ 125

MZ 125 1960

For a long time four-stroke engines of medium and large displacement dominated motorcycle technology. Subsequently smaller vehicles followed what seemed an axiomatic principle in adopting the two-stroke cycle system that had been invented by the German Otto. The disappointing results obtained by Garelli and then by DkW were considered irrelevant exceptions.
When DkW abandoned its last version, only the East German MZ persisted in using two-stroke engines. That company went directly into racing to show that the two-stroke engine still had a great deal to say for itself.

There was a certain logic in the proceedings. The MZ company had been founded after World War II on the ruins of the DkW factory in Zschopau. Aside from any political questions, MZ wanted to maintain "homegrown" technical traditions. The original idea came from a local mechanic, Daniel Zimmerman, who had transformed an old DkW 125. He eliminated the old-fashioned cross-port distribution and installed a rotating distributor connected directly to the crankcase pump.

Zimmerman's distribution system was adopted and improved by MZ. Walter Kaaden, the head of MZ's racing department, did some interesting tests on the design of the exhaust tubes and their positioning in relation to the cylinder port. In the end he came up with two engines, a 125 and a 250, and both of them turned in exciting performances.
After factory testing, the MZ company decided to put the vehicles onto the track. The two-stroke motorcycle had been entered in world championship events from time to time since the 1955 West German Grand Prix, but Kaaden and his colleagues did not decide to go into racing on a regular basis until 1958. That year the official MZ racer Fiigner won the Swedish Grand Prix with a 250-cc. two-cylinder MZ.

In 1959 Gary Hocking won two Grand Prix in the 250 class and Ernst Degner—the best racer on the team— beat Ubbiali with an MV in the 125 class at Monza. Degner barely missed  winning in the 250-class competition as well.
As the Japanese began to show up on European tracks and circuits, the Italians and the East Germans fought it out in the Va- and 1A-liter classes in 1960. The Italians prevailed, but Degner won in the 125 class at Fran-corchamps and Imola. He lost some races mainly through bad luck.

Motorcycle: MZ RD 125 Manufacturer: Motorraderwerke Zschopau, Zschopau Type: Racing Year: 1960
Engine: MZ single-cylinder, two-stroke, with rotating-disk distribution. Displacement 123.6 cc. (54 mm. x54 mm.)
Cooling: Air
Transmission: Six-speed block
Power: About 24 h.p. at 11,000 r.p.m.
Maximum speed: About 110 m.p.h.
Chassis: Continuous, tubular, double cradle. Front wheel, swing lever and shock absorbers; rear wheel, telescopic shock absorbers
Brakes: Front and rear, central drum

MZ 125 1965

Italian, British, and Japanese motorcycle manufacturers all followed the lead of MZ and began to revive the two-stroke engine. Meanwhile the East German company continued to fight for the 125-class world championship.
MZ kept on with the 250 as well, but the company either did not realize what a fine vehicle it was or had drivers who did not adapt to it well. The motorcycle had plenty of power —45 h.p. at 10,500 r.p.m.—but it was defective in stability because of the encumbrance of the two cylinders on the side and because of the poor distribution of weight.

Ernst Degner and Walter Kaaden concentrated their efforts on the MZ 125 single-cylinder. In 1961 it generated 25 h.p. and had a top speed of about 125 m.p.h. That year Degner set his sights high. He was up against the big Japanese Honda team, which had very up-to-date four-stroke motorcycles that were ridden by the finest European racers.

The duel between MZ and Honda in 1961 went down in motorcycle racing history. Degner won the two German Grand Prix as well as the Italian Grand Prix at Monza. And at Hocken-heim he came in first followed by Shepherd, Fisher, and Brehme, all of them riding MZs. It was a dazzling team victory, but Honda won the world championship. The Honda was no faster than the East German 125, but it was ridden by top-notch racers like Phillis, Taveri, and Redman. After such an exciting season one might have expected MZ to press on, but MZ cut back instead.

The main reason for MZ's cutback in racing was the loss of Degner, the only racer who was considered good enough to ride the MZ to victory. He defected from East Germany and was immediately hired by Suzuki. The Japanese company hoped to learn from him the secrets of the fine MZ engines.

After Degner left East Germany, Alan Shepherd became MZ's number-one driver in the 125 class. But his chances of winning were slim because of the political tensions between the Communist bloc nations and Western Europe. More than once racing MZs were blocked at the customhouse and failed to gain precious points for the final classification.

The only bright note for the MZ team in 1962 was Mike Hailwood's second place in the 250-class competition at the East German Grand Prix.
With the same MZ 250 two-cylinder (with an improved cooling system using water, like that of the 1962 single-cylinder 125), Hailwood captured the 1963 East German Grand Prix, giving MZ its first win in that class. It was not until 1964 that the MZ had garnered another first place.

That year Shepherd, in his last season with MZ, won the U.S. Grand Prix at Daytona Beach in the 250 class.
At the beginning of 1965 MZ set its hopes on the 250, which generated 48 h.p. at 11,000 r.p.m. Because of the motorcycle's fine performance, the company thought about going into the 350 class, which it had raced in only occasionally.
A more powerful version of the 250 was built by MZ for that purpose, and Derek Woodman rode the new model in the 1965 world championship. It was the most competitive of MZ's three-cylinder vehicles. In 1966 Heinz Rosner joined the MZ team, but the results were disappointing.

MZ's failure was inexplicable. Every year the company began the season with technologically advanced vehicles, putting motorcycles into the field that only the Japanese could match. And every year they turned in only modest performances, despite the fact that the factory tests had promised more. The single-cylinder 125 generated 30 h.p. and the two-cylinder 250 generated 50 h.p.
Woodman and Rosner continued to race MZs in 1967. That year it was the 350 (actually a 300-cc, because the cylinder's thickness did not allow any increase beyond the original 250-cc.) which performed best. Rosner, who was a better racer than Woodman, won second place in Czechosloakia and captured third place in Ulster and Italy.

MZ fared much better in 1968, when Rosner (alone on the team) came in third in the world championship in the 250 class, fourth in the 125 class, and fourth in the 350 class.
In 1969 a new problem presented itself. The revised formula prescribed a two-cylinder, six-speed limit for racing, which should have worked to the advantage of MZ. Instead it turned out that the two-cylinder traditional-feed Yamahas, which were freely sold to private racers, were the motorcycles to contend with, in part because of the determination and ability of the men who raced them.

That year competition became tougher for Rosner, Braun, Bartusch, and Szabo, the racers who alternated racing official MZs in the three categories. And this notwithstanding the fact that the horsepower of all three models had been increased.

In 1970 MZ- had a 58-h.p. motorcycle in the 250 class, and the 125 engine was completely rebuilt. The same longitudinal axis had two water-cooled cylinders fed by two carburetors with rotating disks on the right side of the crankcase. The engine generated 32 h.p. at 13,000 r.p.m., but even this was not enough to beat such formidable contenders as Derbi and Suzuki.

Motorcycle: MZ 125
Manufacturer: Motorraderwerke Zscho-
pau, Zschopau Type: Racing Year: 1965
Engine: MZ single-cylinder, two-stroke, with rotating-disk distribution. Displacement 123.6 cc. (54 mm. x 54 mm.)
Cooling: Water
Transmission: Six-speed block
Power: 28 h.p. at 12,000 r.p.m.
Maximum speed: About 125 m.p.h.
Chassis: Continuous tubular double cradle. Front and rear, telescopic suspension
Brakes: Front and rear, central drum