RE: hpi wheels on redcat dunnrunner
ok, the rampage has a 22mm hex with a 23mm nut, the hpi has a 24mm hex.
there might be a adapter kit out there, but i couldnt find one. i did find one that lets you use rampage tires on a FG.
you can use JBweld on hpi rims to make them work on the stock rampage hex. put jb weld in the wheel hex, put it on the rampage hex(use seran wrap over the hex so the jb weld doesnt bond to the hex) and bolt it down (make sure its centered). the jb weld will make the hpi rim's hex smaller and fit the stock axle.
not sure i would do it just to run hpi rims, but its a cheap option that some have done. i do know that jb weld is a good fix if you strip out the wheel hex of the rim.