I've wondered about this stuff for a while & can't make my mind up if it's good or bad, that green goo stuff goes in the tyre & stays as goo,, my thoughts are, that bike parked overnight, all this stuff settles at the bottom of the tyre & must affect balance when you first when you jump on for next ride,,,,, the other system that blows up and seals the tyre in one go,, well I wouldn't hold my breath,, although I must admit I bought one, (reduced in tesco) with trip round Scotland planed & some of the roads we would be going on, thought it might be worth a try & if it works all well & good, but as I say, I wouldn't hold my breath,, one thing's for certain,, you ain't going to be Mr popular when you take your tyre to be changed