Interesting problem that one, could the valve have been defective or not installed correctly?
This did cross my mind , especially as the tyre is very new and has neglible miles on it but I dont have any way to prove what has happened. I dont think the evidence of a perfect tyre but with the valve hanging off will count for much. Pressure was 25PSI (i.e. stock pressure for the rear ) checked that morning. I think I will experiment with it good bit higher.
