TSDZ2 - Dual Chainring - a solution that works

I demonstrate how to get a dual chainring working on tongsheng TSDZ2. To accomplish that I replaced the "modern" derailleur with a "vintage derailleur". The model I used was Shimano Model FD-738 with 34.9 mm clamp diameter - probably from the mid 90s. I believe that other vintage series from Shimano e.g. LX, Alivio or Deore will also work. I hope this helps! If you have any suggestions or questions leave me a comment.