[Harrison]

Low and centre is the basic rule for weight distrib..

But, you also want to have weight over your drive wheels (if you only have 2) so they will skip less. Of course if you have 4wd, then low and middle holds true.

But, keep in mind that the "middle" is an average of all the weight on the bot. Like if you have something hanging off the front of the bot, you might want to mave everything back slightly in the bot, so that the average of the 2 weights is the middle.