Originally Posted by
Al1943
Whoa.
After mounting the tire and before inflating push the valve into the tire to allow the tire bead to seat properly into the rim walls. After the beads are fully seated then pull the tube to the rim (actually the pressure should do that for you).
The tube can get stuck under the bead and inflating them pinches the tube. I put a little air in the tube after getting the tire back on and then make sure the tubes is not pinched especially near the valve. Like the previous poster said, push the valve into the tire to make sure their is no pinching then inflate before tightening the valve nut.