I am using these 4 inch diam tires that are about 1/2 inches wide. They work but they look stupid. My brother has a six wheel drive tractor trailer that runs off an electric K'NEX motor. He converted it from a six wheel drive rock crawler. I have a 4WD rock crawler run by an electric K'NEX Motor. Runs very well. Can flex 90 degrees without snapping
I made some smoother working shocks out of different positioning. I really need more pieces to make it be able to have 4WD. That would be awesome!
Any pics of the rock crawlers? What do they run on?