Hi I have a 2006 Big ruckus, its great but I do all of my computing on a dirt road, Can any body help me get some knobby tires? I can not find any at all!

If there are none can I change the rim out to a size that would allow for some good ***** yet still not lose the size of the tire, Is that posable ???

If anything Id like to go to a bit bigger of a rim.

Any advice is appreciated thank you!