I undid the air valve cover on my slants to adjust the pressure. Whilst doing this I started to hear a hissing – foolishly I carried on unscrewing the cap. Eventually I reached the end of the thread and it flew off at speed narrowly missing my forehead and placing a small dent in the ceiling!
Turns out the valve core is contained within a double threaded aluminium carrier which itself threads into the uppers and the aluminium dust cap/cover. If the thread is slightly looser on the forks than the cover then it can come free before being de-pressurised.
I think the short term answer is to put a couple of drops of thread lock onto this component before refitting, but the moral is – if you hear hissing, stop!
Even if I’ve been a bit thick somehow, this seems to be a serious and potentially dangerous design fault. This should not be able to happen, even by mistake!
