I often ride on forest tracks in north Wales and am forever getting small pieces of slate puncturing my tyres. Can anybody reccomend a puncture resistant tyre that doesn't weigh more than the rest of my bike?

Specialized do the Team Control Armadillo and Team Master Armadillo but only in a wire bead and Panaracer do the Fire XC pro with a Kevlar belt but only in 1.8 with a wire bead again. Schwalbe do the Fast Fred with puncture protection and in folding versions from 450g.

Ricci ltd (www.ricciltd.com) have schwalbe's folding black shark puncture protection for about £23 per pair. About 720g per tyre.

You could try backing off the pressure a little bit (but not so much that you get pinch flats) to see if that would help.

Have you tried some of that slime stuff? Maybe downhill tubes might help as they a bit thicker or finally what about the Stan's tyre sealant, it seems to get good reviews then you can bin the inner tubes and get some heavier tyres for the same final weight!

If the slate is puncturing the tread rather than the sidewall, you could try some slime liners. They are pieces of green plastic that runs under the tread and is 'said' to be puncturePROOF not puncture resistant. Slime offer a guarantee that if anything punctures them, you get your money back. A tenner will do both wheels for not much weight and I can't say I've had any punctures since using them from the pesky thorns from the woods where I ride.