Originally Posted by
JaccoW
You're not entirely wrong. But it often doesn't get much worse than some flyrust on the inside.
This right here is where my trust issues with steel frames come from lol 😅.
On a side note, internal guide tubes (ones I've seen anyway) are usually brass tubes, not steel, brazed to the top tube, so there's really no potential for rust damage, it is the worst place for constant water ingress as the tubing is at its thinnest.