Originally Posted by b4thenite
What do you mean? Would you please elaborate for the noob?
Much thanks to you.
The "valley" is the low point on the rim, from a cross-section perspective. On the opposite side of where you are trying to get the tire over the rim, push the tire's bead down into the valley, or lowest part of the rim in it's center. That will free it up and allow you to get the rubber down over the opposite side. When you air up the tire, it will expand outward uniformly and seat on the rim.