Balancing wheels/tires is a good thing, easier on all rotating parts. Your model will be faster and smoother and handle better because the tires will stay planted instead of jumping off of the ground when rotating.

I built my own balancer here is how........I took a front axle from a duratrax evader and mounted it to a board so the axel sticks out strait. (horizontal) I took a hex drive from an ofna buggy (17mm) and put clutch bearings from an associated GT 3/16 flanged inside the hex adapter. Mount the wheel/tire to the hex and slide onto the axel and put a hex nut on to hold it from coming off when you spin it. Done deal, works great. I use modeling clay or masking tape on the inside dish of the wheel.