I have been commuting on a hybrid for years. A nice CUBE with hybrid tyres with Scrader valve. The odd puncture here and there. Par for the course.
Now I have finally upgraded to a Willier Izoard, with race tyres and Presta valves.
First couple of trial rides, no problem. Then this weekend I went to go out and realised that the tyres were fairly flat. I hadn't ridden this bike for around a month so I figured the pressure had just dropped.
So I topped up with air. Back wheel was fine, took to 110PSI (Max 120). Did the same on the front wheel and went out riding. Within 10 mins, I noticed front tyre was completely flat. It seems the valve failed as I could pump the tyre back up, but then as soon as it released the air just shot out of the valve!
I had a spare tube with me but no pump or tyre spanners. Luckily, I bumped into a very nice Bulgarian chap who was preparing all his kit for a two month cycling holiday and had all his gear literally out in the street. This guy really knew his stuff and within minutes he had changed the inner for me (and way quicker than I could have done it by the way). Had the tyre pumped up (to 100 PSI this time as that's all his gauge went to) and off I went.
Within another 10 mins the tyre was completely flat again. Once more it appeared as if the issue was with the Presta valve, and this time it would take no air in either.
I find it hard to believe that I would get two complete valve failures in the space of ten minutes on two separate tubes, especially when it was replaced by an expert!!
Does anyone have any ideas what maybe going wrong here? I am a bit of a noobie to race tyres so I would appreciate any suggestions? It is a brand new bike, so I doubt it could be the rims, and I checked tyres for holes pinches etc, but it does seem to be the valve. Weird!