Building Seat Support -- Twice

I made this seat support piece and mounted it on the frame.
Then I stood out to the side and looked at it ...
Then I went inside and brought out a long length of chain ...
Put the chain around the large gear on the back and stretched it up over the top chain roller ... there's a problem ... it's pushing upward against the seat support unit.

I also saw that I couldn't mount the brakes on the top of the frame ...
same problem -- chain conflict.
Which means I'll have to adjust the rear dropouts forward ...
I haven't welded them on yet.

Here are the two seat support units side-by-side.
The one on the right will provide enough chain clearance.
If you are wondering what all the little tack-welds are for ...
I found that if I use a single layer of EMT tubing,
it bends when you sit in the seat and move side-to-side.
So, I split the tube down the center ... took one half and using a hammer to tap on it on a round section of tubing. This flairs the outside piece so that it will fit snugly against the other half. Then I tack-weld them together and they make a much more rigid seat support tube.

Here all by itself is the seat support unit that I am going to use.
Good thing I didn't start drilling holes in the main tube yet ...
I'll use this as the jig to drill the holes for the bolt that will lock the unit firmly in place at the proper distance for the new owner.