Here are two video of how to assemble the folding knob on the 2018 WideWheel.
Part 1: the different parts:
https://drive.google.com/file/d/1w-psdSdx_uaPKM1CCkAwc2tYRDQOQqGK/view?usp=sharing
Part 2: how to assemble the parts:
https://drive.google.com/file/d/12nys8wmQvSEQtbdKQII_pYEG126f2SR6/view?usp=sharing