Originally Posted by
FBinNY
A bigger tube might help, but this had nothing to do with your problem. the leaning valve was caused by improper mounting and seating, or the tire creeping around the rim, which often happens if you ride somewhat under-inflated.
That coupled with the weak valve I described earlier is the cause. When you mount the new tube, be sure to keep the valve straight, and the tire seated.
It's leaning to the side so I don't think it's related to tire inflation in any way, and I check my tire often enough that I've never ridden with it under-inflated.
It was fine for the first 500 miles or so, and then I noticed it was leaning to the side. I did notice the stem was pretty tight in the hole, so maybe I didn't get it all the way through. I'll be more careful when I replace it.