Main Tube Bracing

Since this grandchild is known to "fly" off curbs ...
and in other ways test the limits of a bike ...
I figured I'd re-enforce the main tube.
Particularly since I only used 1-1/4" sq. tubing ...
(the plans call for 1-1/2" sq. tubing)

So, I tack-welded a piece of 3/4" angle iron
starting at the large gusset ...
running up to where the BB is set for kids.

Which places a triangular brace most of the length of the main tube.
I figure that should keep the grandkids from
bending the main tube.
I also re-enforced where the main tube and front up-tube meet.
(just in case ... )