Eastern Bloc Motorcycles

I operate and collect motorcycles built in the Communist Eastern Bloc.
At the moment my collection consists of two East German machines.
All motorcycles are registered with standard white licence plates, have valid technical inspections, and are fully roadworthy and legal for operation on public roads.

Simson S51 Elektronik

I have owned this machine since 2019, and I honestly don't know whether I have spent roughly the same amount of time riding it as I have spent in the garage working on it.
This is a true "Chernobyl child" — a 1986 model with the original 6-volt electrical system.
If I ever run out of projects and find myself with a ridiculous amount of free time, I might consider converting it to 12 volts with a VAPE ignition system.

However, anyone familiar with Simsons has probably already noticed that this is not how an original S51 Elektronik should look.
I borrowed several parts from the Enduro version:

• the characteristic high-mounted exhaust,
• the Enduro handlebars,
• the rear shock absorbers (the same type used on the MZ), which can be adjusted for riding with one or two people.
  It would actually be great if the engine could also somehow be adapted for two riders, because 50 cubic centimetres and four horsepower already have enough work to do even with a single average-sized person.

Mechanically, the motorcycle runs without a single fault, but it cannot be said about the the infamous electrical system which has gradually been completely replaced with new wiring and parts - this is where the biggest advantage of this motorcycle is becoming its weight. It is only slightly heavier than modern mountain bikes or durable electric bicycles, meaning that pushing it back to the garage is not exactly a nightmare — even if you are 10 kilometres away.
When it comes to the weirdness and failures of this motorcycle's electrical system, I would probably identify the main cause as something else:

• Communism.

Traditional Communist engineering had a complicated relationship with semiconductor components, especially those responsible for handling higher power levels. On the other hand, Tesla-made (The original Tesla Czechoslovakia, not that e-vehicles american fake) transistors designed for small currents and voltages are almost immortal.
This philosophy apparently influenced several technical solutions used in this motorcycle, for example:

• The electrical system is powered by something that looks like a mutant child of a dynamo and an alternator.
• • The permanent magnet is the rotor, while three coils and a Hall sensor are located on the stator.
  • The first coil generates electricity for the front headlight - so if you are riding downhill at night with the engine idling, you are basically out of luck. It might actually be better if the Moon is bright.
  • The second coil provides electricity for the ignition system. This implementation actually deserves praise. Thanks to this solution, you can completely forget about needing a battery for the engine to run - a battery whose lifespan is roughly comparable to the enthusiasm you feel after refactoring code vomited out by an uncontrolled and badly configured artificial intelligence.
  • The third coil charges the battery. A battery which you technically do not need. At least not if you are willing to sacrifice:
  • • turn indicators,
    • brake light,
    • parking light,
    • horn.

This is probably the right moment to stop and wonder:

• Why, on a motorcycle that is perfectly capable of running without a battery, could the indicators, brake light and horn not simply have been powered directly from the generator as well?

The problem is power output. The generator coils produce, if I remember correctly, approximately 25 W, 21 W and 21 W, so you start calculating the power requirements:

• Two indicators.
• Brake light.
• Eventually horn.

What if you are turning and braking at the same time and using horn for some idiot to recognize You that you are on the road too ?
You quickly arrive at the conclusion:

• "Well... the numbers don't really add up."

The battery therefore works as an electrical buffer. It temporarily supplies the missing electricity for the indicators, brake light, and horn when the generator cannot provide enough.

Speaking of battery charging, this is where we get back to why Communism does not particularly like semiconductor components.

• The charging current is rectified using only a single diode. This means that only one half of the AC waveform is actually used. A proper full-wave rectifier would require a bridge made from four diodes which were already considered an unnecessary luxury.

Semiconductors, however, are not only about diodes. There are also things like MOSFET transistors, which in a normal vehicle could easily be used for something like a voltage regulator. But here the engineers had faced another challenges:

• They realised that what might be acceptable for the front headlight — which barely shines at low RPM — would be a much bigger problem for the rear light.
  The rear light has to satisfy two contradictory requirements:
• • It must shine properly even when the engine is idling.
  • But the bulb must not explode when the engine is revved up before riding uphill.

The solution was actually quite clever.

• As engine speed increases, the frequency of the alternating current also increases.
• A properly placed series inductor becomes a greater and greater obstacle to current flow as frequency rises. In other words, its impedance increases. So, connected in series with the bulb, there is a coil with a ferrite core. This is also the reason why the rear light requires exactly the type of bulb specified by the manufacturer - the entire circuit was designed around that particular bulb. Install something else and you are no longer operating the system it was designed for.

Speaking of the rear light:

• This is actually a component that consumes both direct current and alternating current.
• As far as I know, there is no other vehicle in the world with this particular feature.

The upgraded Chinese capitalist version of Communism is, unlike traditional Communism, a different story. Traditional Communist engineering, despite having two left hands, at least tried to build things properly. The modern version is much more interested in money.
And unfortunately, replacement parts currently available for these motorcycles often do not even reach the quality of the original components.

One example:

• The motorcycle starts perfectly.
• After a short while, however, it suddenly loses power and dies.
• It will not start again.
• Then, after waiting a few minutes, it starts again — and the same scenario repeats.

Based on these symptoms, any mechanic immediately starts thinking about false air entering through worn crankshaft seals.

• So naturally, the seals are suspected and scheduled for replacement.
• Then you remove the spark plug, place it against the cylinder head and kick the starter.
• No spark.
• After another ten minutes, the spark suddenly returns.

Eventually, the problem is "fixed" by replacing the ignition coil. Unfortunately, after half a year of trouble-free operation, the same problem has returned. So now the investigation continues.

MZ 150 ETZ

This is what you could call:

"A Simson that went through a refactoring process, removed the obscure bugs and improved the user experience."

Year of manufacture: 1989, I have owned this machine since 2023.

After replacing heavily worn components:

• clutch,
• kickstarter half-moon gear,
• chain,
• brakes,
• tyres,
• various other consumables,
• exhaust,
• and removing the previous owner's questionable "Tesco tuning",

this machine became a reliable motorcycle capable of handling several hundred kilometre journeys without any problems.

Examples include:

• riding under its own power from Dolný Kubín to Prague (approx. 500 km one way),
• Euro Bike Fest at Pasohlávky (approx 230 km one way).

For some time, I even used it as my daily commuter in Prague, a smaller motorcycle or scooter is basically the only sensible motorised transport there.
Nowadays I live in the Central Bohemian Region in the middle of the forest, but the MZ is still used every day for trips to the village — shopping, post office, and similar missions.

The improvements compared to the Simson:

• Standart electrical system = Alternator → rectifier → voltage regulator → 12 V battery → everything else
• The engine finally has enough performance for normal city and countryside traffic.
• Neutral indicator -a small but welcome improvement, even strong sunlight seems to destroy this feature.
• Standard headlight bulb - a proper 12-volt bulb with an H4 socket.
• Better brakes - especially the front disc brake with hydraulic operation.
• Higher top speed - somewhere around 100 km/h.

Simson vs MZ

The only thing where the Simson is clearly superior is fuel consumption.
The MZ uses approximately 4.5 litres per 100 km, so riding it is not exactly a way to save money once you consider that two-stroke oil (M2T or an equivalent) also has to be added to the fuel.
The Simson, on the other hand, has almost unbelievably low fuel consumption. It is basically the kind of motorcycle where you fill up the tank twice for whole season.

Events 2026

Euro Bike Fest: https://eurobikefest.cz/

Na pionieri okolo Tatier (Around the High Tatras on Pionier): https://www.ruzomberok.sk/podujatia/okolo-tatier-nielen-na-pionieri-2026/

Jawa Čezet stretko Tužiná (Jawa/Čezet meeting in Tužiná): https://www.kamnamotorke.sk/motoakcia/jawa-cz-stretko-2026-15-rocnik