I have a 2010 YZ450 on the way, and while I already have a MX51 front tire ready to put on, I'm not sure about the size of the rear? I've ridden 250 2-strokes my whole life and therefore am only familiar with 110's. Do I order a 110 to switch that out too? I understand the concept behind the fatter 120 tire, but what are the actual differences in feel? Also, does anyone know the 2010 yz gearing? 13-48? Thanks.