My thanks go to Yvan Vertongen
for these photos of his Simson Duo 4/1. Yvan writes:
I bought me this summer an "new" 3-wheeler. It 's an Simson Duo 4/1, build in 1977 in the DDR. In fact, the 3-wheelers were constructed by VEB Robur-Werk 5 with the parts of the Simson moped "Schwalbe" till the end of the '80s. Like my Velorex 16/350, this 3-wheeler is also build for invalids .. [and it has] no pedals.
The 49 cc - 1 cylinder - 2 stroke - 4.5 HP - engine
gets the 321 kg heavy 3-wheeler an maximum speed of 55 km/h. The large stick is for the gear-box, the small one for the hand-brake and the lowest one for the start-up of the motor. The 3-wheeler, I bought in Blankenheim - not far from the Belgian frontier, is intact. I only have to repaint it in the original colour (= orange). The firm Simson still exist and still makes motor cycles: