Nope, did not ask yet. Yeah, I know Permatubes suck, but if I have to choose to have the bikes on the road or standing in a shack 15km from the mechanic and the school, then I choose permatubes. Problem with slime is that if there is a puncture that the slime do not seal, then you throw away the tube. Not even patch and solution sorts it out. Tire liners are options, but again, not failproof. The only solution that is failproof is some kind of a permanant tube in there. There must be someone out there that has a better solution, or otherwise I will have to get some plastic specialist to make me something.