The 'problem child' remains the Tragarmhalterung

The stand is Ok. The 'problem child' is the twists if you fixed the bike at the seatpost, the Tragarmhalterung. I have also fixed the bracket with a threaded rod, yet everything remains still pretty shaky (the plastic is here quite by. The rest of the stand is quite massive and strong. Even the workmanship is good. The support mechanism can be adjusted well to the pipe diameter. Clamping is very simple.

My Conclusion:
No comparison to a professional stand! Not for work on the crank! (Practicing here much strength against / on the stand off).
Change for all other chores like cleaning, parts, brakes / circuit level OK.