DKW RT 125? The same bike that was handed over to BSA and Harley as part of Germanys war reparations? Heard that BMW had a very limited version also? Could be just a rumor, but thought it might just be your bike.My bad, do tell the specifics, as the rumor also was Yamaha also had a version at one time?...
ding ding ding!
Harley and BSA had the 'legal' copies (hummer and bantam, respectively), but it was illegally copied worldwide. Russia actually stripped the DKW factory bare and shipped everything back home, basing several russian models on DKW designs.
the RT was also copied by a Japanese music company breaking into the motorcycle market...Yamaha called it the YA-1 and it was their 1st production model.
So what was so special about this bike that so many companies either forcibly took the design or outright stole it? For one it was a 2-stroke with fewer moving parts, making it relatively easy to manufacture, and it used loop scavaging as developed by Anton Schnurle, which vastly improved the power made by 2-strokes (remember, this was years before Walter Kaaden developed the expansion chamber and boost port working for the same company)
DKW became IFA after the war, then MZ shortly after that. From the mid 90s until they stopped production a few years ago, MZ sold a model called the RT125, ironically enough a 4 stroke.