[censored]! Perhaps I don't have enough experience of phaaaaat tyres then. Type of tube and how fussy one is about optimum pressure definitely makes a difference though, and I don't suppose you know how hard those tyres were in the first place - could have been rock hard.
55psi in the autumn and still 55 today - I checked cos I knew somebody would query it:-)
From earlier in the thread it was suggested that thumb pressure is the best indicator of tyre pressure - dead right and saves time too.
A thorough check of the inflated tube under water should reveal any problems (include a wiggle/tugging of the valve under water to test its base).
I rarely fix punctures nowadays - tubes at trade price are almost as cheap as good patches:-( but for those who are still learning about fixing punctures make sure that you blow the tube up to 3 or 4 times it's normal diameter before you put it in the water and pay particular attention to the welded(?) joint. If you have a puncture (leak) at the joint just bin the tube it will only get worse.
A presta tube will normally hold normal pressure whether the nut is done up or not. The only time it might release air through the unlocked valve is if it's ridden when centrifugal force and bumps may cause the valve to momentarily depress.
I had a faulty one once, where the thread between the inner and outer parts was leaking. I unscrewed it, using pliers, wrapped a bit of Plumbers Tape For Everything round the thread and screwed it back in. Fixed.
Tim --
fast and gripping, non pompous, glossy and credible.
