Chances are though if your tire is not seated correctly it will be ever so slightly eccentric, causing you to feel a little bump with each rotation. This will be more noticeable the faster you roll.

Have no idea about fractional versus decimal tubes but Bell is just about the worst you can get. I'd stay away from any tubes that say made in China at this point, AFAIK the most reliable tubes are from Taiwan. Also if you took the tube out of an older tire, it could have been already damaged. The difference in psi is negligible, neither 50 nor 60 is very high pressure these days.

Hope you have better luck in the future, bro.