has anybody had this problem ??? sundays ride stuffed because of a flat tyre ,jacks came over monday , pumped the tyre up , we checked the tyre , no nail. no splits . no obvious leaks , the tyre stayed up !!! finally figured it out , i had bought a set of skull valve stem caps , the thread was short , so when they were tightened opened the valve , bingo !!! flat tyre , took them off , no problem since .

shit hey...........i was only today looking for something like that.........ill be a little more careful with em if i get em........
so u needed to piss em orf or just not do up all the way????????????

not a fan of anything like these, the heavier ones can also throw your wheel balance out ..........

thanx mate....off the list now

I was looking at getting a couple of those caps, maybe i'll do what I did with my purple dragster in 1973, put  some spit on the valve and look for the bubbles.....memories...

mine have been ok

I got a set of chrome caps from my local tyre shop, they cover the whole thread on the stem and have a rubber ring at the top to seal if the valve leaks. That are smooth with a little knurling at teh top and look pretty good.

Why not get the skulls and an old valve stem minus the valve, screw them together to protect the thread, stick them in the vice (stems), put a drill up the middle and drill out the sculls a bit to give clearance to the valve thingy.
saves you throwing them out