I have a 2000 yz 125 and new some new tires bad.I was looking at the Michelin M-12's, but could not find the same size for my front or rear tire.Right now my fron is a Dunlop 756 80/100-21 and my rear is a Dunlop 100/90-21 and all the tire sizes are to big that are listed.I have heard that their tire sizes run small, but how small?Thanks