i just pulled a +4 off and installed a +2 today, now both my banshee have +2's .. but i ride mostly trails and hill climb, i think a lot of it has to do with rider weight and tires.. if you are heavier go longer, if you are a small guy don't go so long, the rider weight has more to do with it than you think.. a +2 does fine for my needs, i am selling the +4 if you are interested.. it is a lonestar and is basically brand new, i installed it along with my new cub motor, rode the bike around to break it in, then decided it was too long,, 300 shipped.. a loss for me.. later