That is clearly a glass cut on the thread and probably a pinch cut on the sidewall. Riding on roads where glass is present is a lottery in spite of your tyres. Further, there is no such thing as a puncture proof tyre, no matter what the manufacturer claims. Think about it for a minute: Tyres are constructed by wrapping some fine cord over a mould and over two hoops made from wire or a type of cord. Then rubber is moulded over it. How do you expect sharp objects not to penetrate? I've heard some people say that the weave is made of Kevlar and therefore puncture-proof. Not so, would you put a piece of cloth weaved from Kevlar on your arm and then stab at it with a sharp object and expect it not to penetrate? How's the rubber going to help?
Further, riding on wet roads lubricates the little glass slivers and help them cut through within a couple of revolutions. How well water lubricates rubber is something well understood by people who work in laboratories. Rubber Bunsen burner tube is difficult to cut unless you cut it under water, then the knife just glides through it. Same with glass and wet roads. Wet roads also camoflauges the glass so you can't evade it.
The only way you can protect (not proof) yourself against glass is to have tyres that are thicker than the average slivers of glass. Problem is, such tyres are very sluggish and hard to pedal.
Hi, I have posted before regarding these tyres and I praised the. Unfortunately I spoke too soon. I have done approx 300 miles on them an this is the result attached.
