none what so ever.
Too true. I have to tighten the valve cores of all continental tubes with a pair of pliers before I use them for the first time, otherwise if I ever need to pump them up by the roadside with my Lezyne pump that screws on, rather than the track pump that just slides on, it unscrews, pops out and lets all the air out - so they're essentially useless with a screw on pump.On the last continental tubes I bought, the valve cores unscrewed as I undid the pump. Ever tried to find a valve core after it's been fired at 100psi?
As tubes go I do prefer them over others I've tried including specialized and some cheapie ones. I just have to remember to tighten them up or I could end up stuffed if I had a p*******.Had one conti tube blow the valve out but otherwise found them excellent. I use the supersonic tubes in my clinchers and also conti tubular tyres which I assume have conti inner tubes inside them.