does anybody know what size the rims are on this bike? It has a 2.50 X 17 tire on the front and a 2.75 X 17 on the rear. Reason I ask is I put a 125 lifan in the bike and would just like to drive in on the trails. I want to put knobbies on it . Its easy to find the 2.75 X 17 tire but I can find the 2.50 X 17. I was wondering if I could run the 2.75 on the front. Great site been plenty of help!!