couple questions- wheel size and stance

[interceptorz28]

So, what is the pos. and negatives of running 18's out back and 20's up front? I think this is a MX setup, but why? what does it help? I know you lose some clearance out back.

Also, I forget which should be wider. Should the front end be slightly wider than the rear? or the other way around?

[underpowered]

most people run 18" and 20's on MX quad to keep the center of gravity low. they don't need the extra ground clearance so they run the smaller tires to lower the CG.

and usually most run the front end slightly wider than the rear.