Originally Posted by Jipe

Thanks for the information.

The rear rack of this video is different from the one of the previously posted video (see at about 4m10s) its only attached to the rear swing arm and folds with this rear swing arms (while the previous one was attached to the rear swing arm and seat tube of the bike main frame).
The drawback of this design is that the folded Helix cannot roll on its wheels anymore, the rear rack is on the ground, not the rear wheel.