[EricVicenti]

Many teams choose to use #35 chain, but in my experience, it is way more bulky and heavy than necessary. Team 8 uses #25 chain. Keep in mind that tensioning is very important. The two ways of tensioning are to pull the wheels back, or to push the chain down, either with an idler sprocket, or some other material that wont wear out, such as HDPE.

Also, most teams don't directly drive any wheels with 6wd, which isn't a bad choice, but in terms of simplicity, we choose to drive the center wheels, and to have 2 chains run to the front and back. This year, we originally designed our drivetrain to use AM super shifters. When we found ourselves nearly overweight, we decided to make our own gearboxes from the toughboxes and the supershifters, so we ended up with non shifting gearboxes, 8:1 ratio (fairly high, higher than either the toughboxes or the supershifters), the size of toughboxes with the mounting pattern of supershifters.