I am not sure how much it weighs, I need to go through the densities and weight values of the components yet. I will put post them after I go through them. They are 3x1.5" tubes, and when I did a quick check before, going to 3x1.5" from 2x1" adds a few pounds.
My thought on the tensioning, if it is like you say that once they are tensioned the belts are all set. Why not design the proper tension in the c-c distance between the axles from the start? I don't have as much experience with belts as others do in FRC, but that doesn't seem like too much of a stretch (no pun intended
). If there is other experience out there saying differently I would appreciate the correction.
Attachment is a mix of rivets and bolts. I did not go through the detail of adding those into the CAD yet. Basically the front and rear frame rails will be bolted to the main side rails, and the bumper rails are riveted in place.