Both of my kids have bikes that they ride regularly. The problem is if either of them goes a day or so without riding the bikes the tires are flat. For some reason the bike pump is a very elusive item at my house so getting tires filled up is a pain for me. A new design concept is up to get funding on Kickstarter looking to bring new tires for bikes to market called the PumpTire. These tires will never need to be pumped according to the designers.