I am drafting a question about a frame problem, but I'm struggling with terminology.
It seems "appropriate for stack-exchange" to start by asking about the terminology first.
What is the name of the part that connects the brake pivot to the frame?
And what are the sub-parts of it called?
Here are the best names that come to my mind, followed by some photos.
The whole part: brake pivot base (which is clearly made up of four plates)
1: Pivot plate
2: Top plate
3: Bottom plate
4: Outside plate
Not numbered: Spring sockets (the holes in the "pivot plate")
Use of "Brake pivot": Obviously, please let me know if you have an issue with the phrase "brake pivot" in the first place. I'm perfectly happy to call it something else: a caliper stud, a cantilever post, a brake boss, or any combination of the above. Personally I am resigned to the fact that there are many names in circulation, everyone has a preference and we will simply never settle on one name.
Let's stick to the question, please: Once again, this question is just about what the parts are called. Let's sort this out and then I will ask separately how to fix the frame. (I will then link it to this question so if you have some ideas already, then please feel free to Follow or Bookmark this question: https://meta.stackexchange.com/questions/345783/whats-the-difference-between-bookmarking-and-following-a-post)
Who cares anyway?: I know that there are not a lot of bikes like this. The bike is a BSO and I know that modern bikes tend to have a much neater setup. However, I would like to think that a configuration like this is not restricted to BSOs and therefore we will manage to establish some names, perhaps with input from those with experience in framebuilding or just general tinkering. And there is at least one bike with a similar setup already documented on here: Can this damage to my brake mounts be repaired?
I'm realistic: I accept that I probably won't get a link to a website that provides an authoritative answer. Just your loose thoughts will be welcome too. And I will fully accept comments on the value of my guesses: if the names I came up with are rubbish/confusing/ambiguous, please tell, I am not going to demand a better idea from you.
Edit: If you want to offer your thoughts on how to actually fix this, here is the question as promised: Brake post broke off the boss. How do I replace it?