My best suggestion to you is to go up to the "Quick Search" box in the upper right and type in something like "treads" or "traction material" and hit search. These topics have come up many, many times in the past. There's lots of information sitting in these boards, and you'll get it a lot faster too.
Track drives can be great for traction, but there are several problems that need to be addressed/considered when designing one:
1. Weight Distribution: The track is pretty much useless unless there are "rollers" that apply pressure to the track. Some teams have let their treads glide accross a smooth surface, like
Delrin, so that the surface applies all the pressure to the treads (and the wheels don't make contact with the ground). Team 92 is one example of this.
2. Traction/Turning: There is such a thing as too much traction. When turning tank-style, the treads have to "slip" accross the carpet or bad things can happen. One way of getting around this problem that we implemented last year (that we borrowed from another team) was using a caster attached to a pneumatic cylinder. The caster would be lowered to raise the front half of our robot, allowing it to turn easier.
Some have used
Brecoflex belts for treads.
Example:
http://www.chiefdelphi.com/forums/at...=&postid=90078