Men over 30, how old do you think is the oldest a man can be to become a father?

That's a personal thing, I know people in their 60s who are fit and healthy, and could keep up with whatever comes their way. I also knew people in their 20s who can't even care for themselves, or keep up with life.

To each their own, but personally I wouldn’t have kids after 50. I know someone could be really healthy at 50-60 (sometimes more so than people half their age) but the body starts to kind of take its own course after 70. For me it would be more about the kind of quality time I could spend with my kids. I don’t want a teenage kid having to deal with a parent dying of old age or illnesses, which is totally possible if you have kids after 60.

I know someone who became a father in his late 70s (incredibly funny because when he and his siblings inherited things from their parents he paid them to get - I think it was a house - all by himself, they gladly took his money, thinking they'd get the house back anyway when he dies since he had no children at that time)

I agree this depends on the couple, and the man in question. Two people supporting each other might make better parents than either alone. I went to highschool with a guy whose parents had him when they were in their sixties; they were nearly 80 when we were graduating. He turned out fine!