goo_mason said:
You
can avoid obvious broken glass / sharp detritus, but there's some stuff you'll never see which can still puncture your tyres. Tiny sharp pieces of stone, thorns, police stingers for example....
How many people, I wonder, look carefully at the stuff they dig out of their tyres on their routine inspection (assuming you all
do a routine inspection that is!
)
I would say, about 90% of what I prise out are little fragments of flint or chert (a hard brownish rock similar to flint). Mostly about 1-2mm long and very sharp edged. Not surprising, seeing as I live in the South Downs area (chalk and greensand) where these kinds of rock are extremely common: there's no way they won't be liberally scattered over every road in the district. And you haven't a prayer of spotting such fragments lying on the road, even if you do the Sherlock Holmes act...
The remaining 10% will be broken glass and thorns: you have a slightly better chance of spotting those in time, but I challenge anyone to claim to have spotted an isolated 2mm sliver of glass just lying on its own in the road while belting along at 20mph+...
I very rarely find any bits of metal in the tyre, I can't remember the last time metal caused a puncture....
Of course the big advantage of puncture-resistant brands is that the flints etc. take
longer to penetrate them, so you have more chance of spotting and removing the flint in your regular inspection. But they only postpone the puncture: if you neglect your tyre you'll get the puncture in the end! And with larger fragments of glass, or long thorns, you stand no chance!
Another bummer is when a flint
enters the hole left behind when you previously extracted another flint. In that case it's got less distance to travel...
!