Originally Posted by
3alarmer
...spreading the rear distance by pushing or pulling on the dropouts is not a good practice. Eventually, you will encounter a frame where the brazing lets loose (where the dropout is inserted into the stays), and the frame will be damaged. It can still be repaired, but only at considerable cost and effort. Same thing with working on a fork. pull or push on the frame member, not stuff that is brazed onto it.
If the dropout comes off with that little sideforce, it was going to break off anyway. Better to know now than after lot’s of time, effort and maybe dollars had been put into the project.