This is our robot as of Sunday. We got the drive train done Thursday night and have been working long days to get this thing done before the shipping date. We used V-Belts for our track, simple and very effective. This is our first year for building a tracked robot. We have been trying to construct an arm for grabbing the big ball; hopefully we’ll get it done before the shippind date. If not, we’ll have a lot of work to do in the pit area at the competition.
Our team decided to make a track system for our drive train this year. We used V-Belts for the tracks, so the tracks are very strong and provide a lot of traction. We were a little worried about belt slippage, since there are no cogs on our belt wheels or anything to provide reinforced grip on the belt, but we haven’t had a problem. Everything is gripping and works great 
This year’s drive train was a big jump for us. We used casters and back drive wheels in our first two competitions.
I am wondering how many track robots we will see this year. Tracks seems to be the way to go for getting on top of that center platform, especially if you’re trying to get directly on top from the 6 inch high side.
My Team 61 uses tracks and has for 10years now. We use them becuase there reliable unless you have to much power then you rip them.
http://www.valleytech.k12.ma.us/robotics/images/2002Pictures/MVC-671S.JPG
Not many teams have done that =)
http://www.valleytech.k12.ma.us/robotics/
Click on photo galley and you can see how we have inproved them year by year.