I just stumbled on this thread, and noticed that i never posted the actual culprit responsible.
It was me, in the garage, with a spanner.
Joking aside, it was all caused by a fault in the braided brake lines.
It was the ONLY thing left to change, but because they were braided i bought new lines reluctantly still thinking there was no way it could be them.
They were somehow expanding on braking, which i could understand with unbraided lines, but not ones with a metal wrap around them.
The bike was in a story state when i bought it, due to it being treated as a bit of a toy by the previous owner, so it really needed a lot of TLC, but that was why i got it very cheap.
Anyway, after a lot of time, money, and effort, once the new braided lines were fitted the whole issue went away.
