2 AndyMark SuperShifters + 4CIMs and associated pneumatic shifting accessories is ~16.5-17lbs by itself. Simply changing your strategy can change your weight allocation. (4CIMs = 10.4lbs, 1 SS= ~3lbs each). 2011, 2008, 2007, shifting was desired by many teams since it was a high-speed open field coupled with some fine movement control. In 2010, many teams didn't need shifters -- single speeds between 10-11 ft/s were fine and controllable. Yet in 2007, 2008, and 2011 plenty of teams were very successful with a single speed drive train.
The KOP frame itself weighs a bit -- 13lbs with all of its bolts and blocks if I remember correctly. Honestly, weight is the only issue I have with it. You may be able to save 2-3 lbs if you can fab your own plate gussets and use 1/4" rivets to hold it together, but I'm not sure.
This frame weighs under 7lbs after all of the bolts for the wheel blocks (black) are added. However, the frame rails (purple) are welded together; if you don't have welding capability then the KOP frame or 80/20 could be subsituted. Before electronics that drive train is a hair over 30lbs. Usually we allocate 35lbs if we do shifting, yet we can also get the frame welded.
Using #25 chain instead of #35 chain can save ~1.5-2 pounds but adds alot more fickleness to precision in sprocket alignment and tension. Chains have been our achilles heel some years.
The 2 teams I talked to with Nanotube frames said they're great. Drive the center wheel via chain and you're set. The hardest part was figuring out how to mount bumpers and a super structure to it.