Why not try"StopFlat?" This is a strip of puncture-resistant material that fits between the outer cover and the tube. Carry one with you, then, next puncture, arrange the StopFlat around the inside of the outer cover before putting the tube in. For me, cycling used to be characterised by "punctures and headwinds" but frequent punctures are now a syndrome of the past. Of course, now and again one will still get a puncture, as I did recently- inspection of the outer cover whilst it was off, revealed what looked like a tiny tin-tack, however, upon removal (pliers were needed!) it turned out to be a thorn, so hard and needle-sharp that, caught by the tread at an unfavourable angle, just went straight through everything!! I discovered the StopFlat whilst searching for something else on SJS Cycles web-site and decided to try it.