Tyres reluctant to inflate

[Mortiroloboy]

Thanks for the info guys - the problem was that I had not had any experience with this type (Presta) of valve before and was, indeed,, not releasing the the teeny tiny thingiemebob on the valve...we live and learn and, who knows? one day I may even be as mechanically adept as my dog!

Told Ya!

 

[02GF74]

The teeny tiny thingiemebob on the valve is very important.

It stops the valve opening due to centripetal force so you must always do it up fully.

Also you will find that the cap narrows toward the top so that if you replace the cap with out doing up the teeny tiny thingiemebob on the valve, it will push the valve open letting the air out.

Likewise to pump up a tyre, the teeny tiny thingiemebob on the valve needs to be undone - sometimes I find you need to press it in as it can stick and the pump is insufficient to open it.

 

[BentMikey]

Do you really think that's enough force to open the valve against 120psi? I'm very doubtful...