From what I understand, the longer the chassis' orientation is (where distance from center wheel to front or back wheel is < center left to center right wheel), the more severe the center wheel can be dropped without compromising stability, meaning the chassis will remain closer to level. The larger the center wheel is dropped, the less likely scrub will occur after other variables are accounted for.
I have never worked with pneumatic wheels so I am not to familiar with how they preform on a field, but as stated above, over inflating the center wheels seems to be a reasonable workaround to tire scrub.
Team 1114 Simbotics did a remarkable job explaining the physics at play behind every tank drivetrain in detail @
http://www.simbotics.org/files/pdf/drivetraindesign.pdf
I encourage everyone to give it a read when considering or designing any drive train
The major items of FIRST are still what they always were.....understand the game, build a reliable quality machine to play it, train you drivers to use it to its full potential. If you do these things, you can win with or without any specific machine feature. - Jim Zondag [more] 
22-06-2016, 18:34
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