[ChrisA]

When working on the Wildstang bot last year, we tried to stay completely away from tank style turning as we had to overcome so much friction. While we were on the top of the HDPE we found we were able to perform the tank turning because of the slicker surface. The only other way we found to turn was with monster truck turning. This caused us to build a small drop-down skid which propped up one side of our robot and allowed us to do tank style turning on only 2 wheels and the skid.

With all the wheels linked, you will be limited to what you can do. Hopefully this helps.