After some time I discover that stands are completely useless for me, so I decided to keep the bench
and make bicycle repair stand from the stands.
Step 1: At first of all project.
The original weight stands are made from square steel pipes/profiles 40mm diameter.
What I used:
some old front hub with skewer (actually only axle with cones/nuts and skewer)
piece of 5mm thick plastic
Some 10/8/6mm screws, washers and nuts
10/8/6mm drill bits