A bicycle can have any of three valves in its tyres. Presta, Schrader or Dunlop/Woods. The Presta valve is the thinnest of the lot and used in tyres that typically have very high pressure. It is a much hated valve among average cyclists because of its dainty nature. If you are not careful you run the risk of breaking the tip of the valve.
This is precisely what I ended up doing to my Merida rear tyre the other day while trying to take off the pump from the valve after filling it up. The tip just vanished !!! I even opened up the pump's chuck to look for it. Just couldn't find it out.
The tip in the above picture is missing. I had broken it off while trying to pull the chuck of the pump off the valve. Regrettably I had to replace the tube with a Maxxis one that I had. I still have another brand new Schwalbe in stock. The tube that I damaged is the original tube that came OE with the bike. This tube taught me two important things in cycling repair and maintenance. A. It taught me how to replace a tube on the road. B. Later at home I repaired this tube with my own hands using a patch and rubber solution etc. Once you learn these two basic things your confidence with touring grows immensely.
The only good thing about the tip blowing is that even if you break the tip, air does not go out immediately. It oozes out of the tube the normal and usual way. In fact pushing the last bit of air out of the tube is a little difficult when you don't have a tip. You have to use a pin to insert in the hole that is created and let the air out.
Apparently this tip can be repaired if the core of the valve is a removable one. In my cheap Taiwan made tube the core is not removable. So I have to do away with the tube altogether. I will keep it as a memento.
