I have Michelin on the Peugeot and my LBS put something in there called AirLoc or AirTight??....anyway - since we have horrific thorns out here all our bikes need thorn resistant tubes and Slime or this new stuff....it doesn't add any weight to the bike but if the tube Is punctured, it seals the puncture. I'm hoping I don't have to find out first hand how it works but I have a CO2 cartridge just in case!
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"