I'm designing a drivetrain for the offseason, but after doing some math the ground clearance looks pretty unnerving.

The robot is a 6WD, center wheel drop 1/8", with 5" Colsons. The math shows that the outer wheels will have .25" of ground clearance and the middle pair of wheels will have .375" of clearance. I have no experience with what clearance is good or bad, so I need some help.

What would you suggest as the lowest ground clearance for a drivetrain? Are my numbers decent for clearance, or are they too small?