What is the consensus on slime tubes for road bikes? My experience has been less that satisfactory. Last summer I bought two and put them on my bike, or tried to put them on. Both blew out at 85 PSI (the max pressure for the cross tires I was running. I must have forgotten that because I orderd two more last week after two flats caused by small wires I picked up. Last night I put on the front, pumped it up to 120 and walked away. About ten minutes later, POW. Is it me, or is it the tubes.