Any question answered...

Why does my rear tyre keep deflating over night...

I have put three new tubes in, new rim tape, checked the inside of the tyre for sharp bits, checked spokes for sharp bits, Im pretty sure its not a pinch puncture, having changed 100's of tyres and not had them before...

Its a slow deflate always overnight.

Any ideas?

Seems to have been a batch of slightly dud inner tubes, tested the one from last night pumped up high under water and found a tiny stream of bubbles coming from the valve core which didn't seem to be tightened properly, tested the other two tubes and seem to be the same... Fingers crossed for tomorrow !