UKC

I punctured on the way home last night and endured a rather infuriating experience trying to fix it. Firstly I couldn't manage to repair the tube in the dark so I opted for my spare. However each time I blew the tyre up and removed the pump it unscrewed the valve core with it, leading to a depressing deflation for both the inner tube and myself. In the end I gave up and rang for a lift.

Firstly could anyone tell me what the point of a removable core is? More importantly is there anything I can do to stop it coming out? My pump is one of Lezyne ones with a screw-on hose. I just bought a couple of these Conti tubes so I assume they all have the same valves.

In reply to stouffer:

Sounds like a Presta valve.

Yes they are all like that.

Solution....

Tighten up carefully (so you don't damage the thread).
Use needle nosed pliers or sometimes a spoke key will fit.

Look carefully and you will notice a couple of flats on the insert.
Use these to avoid damaging those thin threads.

HTH

E. W.

In reply to ewar woowar: Cheers, yeah I did it up this morning with some pliers to see if that would help, was wondering if it was possible to stick a dab of glue on the thread or anything.

In reply to stouffer:

Removable core is so that the valve can be completely removed - helpful if you're trying to completely deflate the tyre or fill it with some kind of anti-puncture slime.

In reply to stouffer: Removable valve core valves are often used for UST or tubeless so you can take the core out and pour latex sealer in.

In reply to stouffer: have suffered the same problem myself. It only a problem on the Lenze style pumps. Not all valve cores are removable. I would say that about 50 % are and 50 % are not. I always check when I buy a new stock of tubes. If they are I tighten them with a pair of pliers.

As a previous poster suggested a use of the removable core is it allows you to add sealent to your tubes ( totally recommend in winter or for comunting) or to use valve extenders with deep section wheels.

In reply to stouffer:

Had the same issue with my Lezyne track pump. Was advised against using loctite on the threads of the core, for reasons I forget (although I seem to remember thinking the person was talking nonsense anyway). In the end I just tightened the cores in with pliers. Did the job well.

In reply to stouffer: Pliers it is then!

In reply to stouffer: You can get adapter things for Lezyne pumps which make them press on rather than screw on. My preference is just to tighten the valve cores right up when I first fit a tube.