おかしな服{ふく}を着{き}た連中{れんちゅう}には我慢{がまん}がならん。
He couldn't bear folk who wore strange clothes.
My translation comes from the obvious context, plus the fact that Jisho says of ならん "Cannot bear not to". But I can't understand how it works. Should I just learn に(は)我慢がならん as a set phrase, or can the parts be understood separately?
My thought was that ならん may be a contraction of ならない (which seemed like a good idea because に always pairs up with なる). But then I literally have: Xには我慢がならん = patience does not become X. Which makes no sense.
Could you show me some other example using ならん? Do they have to use 我慢?