Originally Posted by BobbyG

I'm sure you meant "pumping the tire". There can be a few reasons for "bumps". Some tires and rims just don't play well together and it makes it difficult to seat the tire evenly. Or perhaps the innertube is caught between the bead of the tire and the rim. Or maybe the innertube is too big for the tire and is bunching up in one area.

There are others here who are better versed in this than I am, I hope they respond.