[MrForbes]

We do pretty much the same thing, I think this year our bare chassis ended up right around 22 lbs, with the supports for the lower mechanisms in place (those 2x4s added a couple pounds). I don't consider this "light", but I also don't consider it to be "unnecessarily heavy", even though it could be lightened considerably if needed. We did a bit of work to lighten the upper stuff instead, and the final robot weight was 119.

I'm all for good lightweight robust design, with efficient material use, etc. I just don't see any need for lightweight wheels, lighweight transmissions, small chain or drive belts, or going to the trouble to cut lightening holes in the chassis, when the effort could be applied to the rest of the robot, with the result that the CG is lower and the mechanism performs better.