Main thing to keep from pinching the tube is to inflate it just a bit, before getting the other bead on. Once the tire is mounted, check the tire and rim on both sides by squeezing the tire and looking to see if the tube is caught. Learned that from bicycle tires. The more you do the easier it gets. I almost like changing my tube tires. I don't do tubeless ones. As I don't want to take a chance and scratch the rims.