MZ ES 175/250/300

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The motorcycles of the series ES 175, 250 and 300 were manufactured from 1956 to 1973 at VEB Motorradwerke Zschopau . The ES series was supplemented in 1962 with the ES 125 and ES 150 .

ES models, 175 cm³

MZ
1960 VEB MZ ES 175slash1 pic2.JPG
MZ ES 175, cutaway model in the Dresden Transport Museum
ES 175
Manufacturer VEB motorcycle works Zschopau
Production period 1957 to 1972
class motorcycle
Motor data
1-cylinder 2-stroke
Displacement  (cm³) 172-173
Power  (kW / PS ) 7.4-10.7 kW
Top speed (  km / h) 95-110
transmission 4-speed
Empty weight  (kg) 141-155

The ES 175, like the ES 250 double port, appeared on December 1, 1956. The structure of the 175 cm³ variant hardly differed from the ES 250. The side paneling was smaller, there were no panniers and the rear fender had one other form. From the beginning the 175er had only one exhaust, the silencer was mounted 4 cm higher and other kickstands were mounted. The cylinders, pistons and cylinder head had been changed for the purpose of adjusting the displacement. During the development of the motorcycle, the demand for a high number of identical parts (efficient production of large quantities and efficient supply of spare parts) took precedence over the desire for optimal adaptation to the performance of the 175 cm³ engine. For example, the frame of the ES 175 is heavier than necessary.

ES 175/0

In 1957 the engine, frame, air filter system , crankshaft , struts and various decorative parts were changed. This achieved a further standardization with the ES 250 . In 1959 the output was increased slightly from 7.4 to 8.1 kW by changes to the cylinder liner, and even more elastic, voluminous shock absorbers were installed.

ES 175/1

With the start of the ES-250/1 series production in 1962, the ES 175/1 also appeared. The ES, which was now equipped with a flasher system, now had the same frame as the ES 250/1, received the rear light of the ES 125/150 and an increase in performance to 12 hp. The engine was taken over from the ES 250/1 and also had the improved clutch , the gear oil- lubricated main bearings of the crankshaft and the sidecar transmission of the ES 250/1. In the test report of motor vehicle technology at the time , the very elastic engine characteristics were positively mentioned - even at low speeds, the engine developed a high torque , which was also maintained in the high speed range of maximum power. Driving behavior and suspension comfort of the swing arm chassis were rated as extremely positive. The very good exhaust noise suppression was also highlighted. The clearly audible, rather unpleasant background noises of the drive wheels in the transmission were criticized, which was due to the arrangement of the clutch on the crankshaft (instead of on the transmission shaft). The speedometer proved to be prone to failure . The ES 175/1 was temporarily taken out of production in 1963. With the discontinuation of the ES 300, however, it is back in the range.

ES 175/2

The ES 175/2 appeared in January 1967. However, it was mostly intended for export, as the performance of the ES 150 came very close to that of the 175 cm³ machine. Only in Yugoslavia and Bulgaria was the 175 cm³ class popular at that time. With the introduction of the more powerful ES 150/1, however, the demand for the 175 cm³ ES almost completely disappeared. The price-performance difference to the 150 cm³ variant was meanwhile too big. A final attempt to boost sales again with the 14.5 hp cylinder introduced in 1970 did not succeed. That is why the ES 175/2 was the last 175 cm³ machine to go into production from the assembly line at the end of 1972, six months before the end of the ES 250/2. Like its predecessor, the ES 175/2 was technically identical to the 250 cm³ variant of the ES 250/2 and also had its elastic engine mount and its angular shape. As with the ES 175 and ES 175/1, the engine was derived from the 250 cm³ machine and initially developed 13.5 hp. From 1970, the cylinder timing of the ES 175/2 Trophy, now known as the ES 175/2 Trophy, was readjusted , the carburettor was changed and a cylinder head with a head gasket and increased compression was installed. The revised engine developed 14.5 hp. As part of the facelift , the now centrifugal governor-free ignition and the optics have also been revised. In the GDR it was last offered as a camping because of the higher payload compared to the ES 150/1 .

MZ ES 175/2 Trophy
ES 175 ES 175 ES 175/1 ES 175/2 ES 175/2 Trophy
Years of construction 1957-1959 1959-1961 1961-1967 1967-1969 1970-1972
Displacement 172 cc 172 cc 172 cc 173 cc 173 cc
power 10 hp 11 hp 12.5 hp 13.5 hp 14.5 hp
Empty weight 141 kg 149 kg 149 kg 155 kg 155 kg
Top speed 95 km / h 95 km / h 100 km / h 105 km / h 110 km / h

ES models, 250 cm³

MZ
Neckarsulm-Zweiradmuseum-Special-Exhibition-2009-MZ-ES-250.JPG
MZ ES 250 (/ 0)
ES 250
Manufacturer VEB motorcycle works Zschopau
Production period 1956 to 1973
class motorcycle
Motor data
1-cylinder 2-stroke
Displacement  (cm³) 250
Power  (kW / PS ) 9.2-14.0 kW
Top speed (  km / h) 105-120
transmission 4-speed
Empty weight  (kg) 150-162
successor MZ ETS / TS 250

The ES 250 was one of the first two models in the ES series. When it premiered in 1956, the partially faired vehicle with a full swing arm represented a contemporary motorcycle. In contrast to western motorcycle manufacturers, who were in a sales crisis at the time, demand in the GDR was unbroken, not least due to the inadequate supply of cars for machines for everyday use with economic features. The MZ ES 250 was suitable for this purpose. The ES 250 was popular not least because of the high-torque engine, which also distinguished many later MZ models. Of the first model alone, over 150,000 machines were produced by 1962. MZ quickly made a name for itself in export with its robust and economical machines. The ES 250 was produced over a relatively long period of time and was modified both technically and creatively. A distinction is made between types 250, 250/1 and 250/2. The latter have a significantly different appearance due to an angular tank / headlight unit. The rigid, non-steering headlight is characteristic of all ES models. As a novelty, when it premiered in 1956, it sparked some discussion because of the allegedly poorly illuminated road surface, just like the low steering angle, which had little effect on driving. In contrast, the advantage of this design was better protection against cable breaks.

ES 250

In 1956 the ES 250 was manufactured with two exhaust systems, as problems with a single exhaust were encountered during development. These early models are called double port . It had panniers, large side panels and a deep-drawn front fender as standard. From 1957 the second exhaust system was omitted and the valve timing on the cylinder was changed. Further changes extended to the frame, air filter system, crankshaft, struts and various trim parts. Overall, there was extensive standardization with the ES 175 . From 1959, even more elastic, voluminous shock absorbers were installed. To distinguish it from the successor models, it is often incorrectly referred to as ES 250/0.

ES 250/1

In 1961 the ES 250 was further modeled as the ES 250/1. The engine now had a modified main crankshaft bearing, which was also lubricated by the gear oil. Intensive efforts aimed at the development of rods - needle bearings from making the engines at high speeds thermally stable, which became necessary in view of further improvement in performance. The needle bearing was first put into series production in the two-stroke engine production of the GDR in 1961 on the ES 250/1, soon afterwards in the Trabant 600 and the MZ ES 150 . The oil-petrol mixture ratio could be changed from 1:25 to 1:33. The front fender, which on the ES 250 was drawn a little longer around the wheel, has now become a little more pointed; the side panels were made smaller and the panniers were omitted. Now with 16.5 PS, the ES 250/1 was also more powerfully engineered, which was very clearly noticeable in practice due to the favorable torque curve. Even at rather low speeds, there was a lot of torque. As with later MZ engines, the machine was surprisingly powerful when measured against the nominal power. The maximum speed determined in the KFT test report varied between 105 km / h when using brackets and the driver sitting upright, and 118 km / h when the driver was lying down without brackets. However, the fuel consumption was not optimal, it was 4.6 l / 100 km in the test average and could increase to 6.7 l / 100 km under full load. The very good swing arm chassis and the good exhaust noise damping were praised as in the test report of the ES 175/1, overall it was estimated that the ES 250/1 would be at the forefront of international two-wheel construction in the quarter-liter class. However, the quality mark Q was not achieved, which was due not least to deficiencies in the Alfer composite casting of the cylinders.

ES 250/2

MZ ES 250/2 with Stoye sidecar Super-Elastic

From 1967 it was followed by the ES 250/2. It had a fundamentally changed frame with an elastically suspended engine. The concept of the supporting engine was abandoned. The angular shape and the wide rib cylinder and cylinder head are characteristic. It was the world's first motorcycle with an elastic engine suspension in conjunction with a long-stroke swing arm at the rear and a chain-driven rear wheel. This development required from the ES 300 caused great problems for the developers. The bearing of the piston pin in the upper connecting rod eye was changed from bronze to needle roller bearings for ES 175/2 and 250/2 as early as 1967. However, the official approval for the 1:50 mixture only took place retrospectively in 1973. From 1969, the MZ ETS  250 rolled off the line parallel to the ES 250/2 . With the appearance of the ETS, the ES 250/2 was also modeled. The engine received a different cylinder with changed timing and inlet shape (from oval to trapezoidal), a cylinder head with a head gasket and increased compression, and a different carburetor. This engine then made 19 hp. With the change to the engine, the ES 250/2 received the nickname Trophy as a result of the international six-day rides it won . The ES 250/2, also optionally manufactured as a de Luxe , rolled off the production line until 1973 . This ended the production of the large ES.

ES 250 double port ES 250 ES 250/1 ES 250/2 ES 250/2 Trophy
Years of construction 1956-1957 1957-1961 1961-1967 1967-1969 1969-1973
Displacement 250 cc 250 cc 250 cc 243 cc 243 cc
power 12.5 hp 14.25 hp 16.5 hp 17.5 hp 19 hp
Empty weight 150 kg 162 kg 153 kg 156 kg 156 kg
Top speed 105 km / h 105 km / h 115 km / h 115 km / h 120 km / h

ES model, 300 cm³

ES 300
Years of construction 1962-1964, 1966
Displacement 293 cc
power 18.5 hp
Empty weight 153 kg
Top speed 120 km / h
MZ ES 300 (YOC 1963)

With the discontinuation of the BK 350 , the Simson Sport 425 and the EMW R 35 from the IFA production program, there was initially no suitable motorcycle for sidecar operation from the GDR. Since the ES 250 was difficult to clamp with its low torque, the 300 cm³ strong ES-300 motor was developed in Zschopau from the MM 250/1 of the ES 250/1. With it you could reach 100 km / h with a sidecar. The square hub (72 mm bore, 72 mm stroke) has a crankshaft, piston, cylinder, cylinder head and a different carburettor that are different from the ES 250/1. The largest ES model was also sold solo for export, but always had problems with vibrations, thermal peculiarities and chassis cracks. Therefore, production was stopped in 1964, only to start again in 1966 for export. So only 7865 ES 300s were built. Externally, the ES 300 differs from the ES 250/1 in the side panels and panniers of the ES 250 and a higher cylinder (14 cooling fins). As a consequence of the vibrations and thermal problems, the elastic engine suspension and the broadly ribbed cylinder for the ES 250/2 were developed. However, an ES 300/2 was not picked up again. Until the ETZ 301, the ES 300 was the last series MZ model over 250 cm³.

Shortly after the start of series production of the ES 300 in the summer of 1962, production of the Super-Elastic sidecar began. In a contemporary test report by the KFT , the ES 300 was not given a good judgment. In addition to excessive vibrations, numerous manufacturing defects were criticized, which among other things led to engine damage on the test machine. With reference to the better liter output of the 250 cc machines, fundamental criticism of the displacement was also expressed, although two-cylinder two-stroke engines with 350 cm³ were not seen as a suitable alternative. As a team with the Super-Elastic, on the other hand, the vehicle was certified to have very good usage and driving properties. In particular, the combination of good suspension and good road holding was highlighted. The maximum speeds determined in trailer operation were 89 km / h and 100 km / h with the driver lying down and without the sidecar window. However, the high fuel consumption of 6.9 l / 100 km on average was mentioned critically.

Web links

Individual evidence

  1. ↑ The new ES 175 from Zschopau. In: Motor Vehicle Technology 2/1957, pp. 51–54.
  2. ↑ Further development of the ES series in Zschopau . In: Motor Vehicle Technology 10/1957, pp. 385–387.
  3. ^ Nationally owned vehicle construction at the Leipzig spring fair . In: Motor vehicle technology 3/1959, p. 111
  4. ↑ Automotive technology tested MZ ES 175/1 . In: Motor Vehicle Technology 7/1962, pp. 284–287
  5. ↑ From the Leipzig spring fair. In: Motor Vehicle Technology 4/1964, pp. 124–125.
  6. ↑ Source: MZ Production & Export Statistics 1951–1986.
  7. ↑ The German road issue 8/1961
  8. ↑ Series two-stroke engines from Zschopau. In: Motor vehicle technology 4/1964, pp. 141-143.
  9. ↑ 250 cc MZ ES 250 from Zschopau. In: Motor Vehicle Technology 7/1956, pp. 255-257.
  10. ↑ Further development of the ES series in Zschopau . In: Motor Vehicle Technology 10/1957, pp. 385–387.
  11. ^ Nationally owned vehicle construction at the Leipzig spring fair . In: Motor vehicle technology 3/1959, p. 111
  12. ↑ Connecting rod needle roller bearings. In: Motor vehicle technology 1/1964, pp. 9-10.
  13. ↑ Motor vehicle technology tested MZ ES 250/1 . In: Motor Vehicle Technology 9/1962, pp. 368–369
  14. ↑ The highest level of technology requires perfect casting quality. In: Motor Vehicle Technology 2/1963, pp. 42–44.
  15. ↑ I drive an MZ. 5th edition 1979
  16. ↑ The German road issue 8/1961
  17. ↑ From the Leipzig spring fair. In: Motor Vehicle Technology 4/1964, pp. 124–125.
  18. ↑ MZ ES 300 goes into series production. In: Motor vehicle technology 5/1962, p. 211
  19. ↑ Motor vehicle technology tested the MZ ES 300 with the "Superelastik" sidecar. In: Motor Vehicle Technology 6/1963, pp. 227–229