I am using ultargatorskin 700 x23c and keep getting punctures which are essentially small pieces of minute glass very hard to detect...should I change the tyres?? it would appear that the smallest shred of glass is able to penetrate the skin of the gatorskins. They have done around 5000 miles?...should I just be more careful where I cycle? it's the kids always smashing bottles glass etc, I do not have this trouble on my hybrid as the tyres are much more solid.....