It’s all fixed now! Further investigation led me to a conclusion that my reckoning about the cause of the failure was right…
Anyway, now I’ve got 180mm on the back. The same model, but bigger. I put 1.5mm washer under the caliper, carefully matching the pads contact area with the disc. It’s spot on. And the brake works so much different! No fade at all, even on the steep bits where previously there was no brake at all (just the burning smell…). I’m well chuffed now! :lol:
I just need to re-learn applying the rear brake, as it’s quite easy to lock the wheel now… :roll:
Not to mention how much more careful I am now with applying the lube and other “bike cosmetics”… :lol: