I'm going to need new rears soon. Blaster came with Maxxis razr 18 rears. I get hung up on trail debris if I'm not careful. I've looked for rears by make/model. The only thing comes up is a 21 Kenda tire. How tall a tire can I run with the factory rim? I have stock sprockets and rims. Front tires are 19 tall. Engine is stock. Any help would be appreciated.