TreeHugger has shown a lot of folding bikes, and most suffer from the same problem: smallish wheels because big ones take up too much space. So mountain biker and designer Duncan Fitzsimons invented a folding wheel. He told Bike Radar:
"The problem at the moment is that in order to get the weight down to a regular bike wheel weight, with the fact it's got hinges and so on, it needs to be a carbon fibre wheel, which means that it's quite expensive, so it's a project that sets more challenges."
"They [bike manufacturers] think you'd have to design a new type of bike to go with it. At the moment I'm trying to find the right type of bike people to work with me.
"The aim is to try to get a really high end city bike or courier bike that can fold up into a package like a golf bag, which could go into an overhead rack on a train or go into a plane locker." ::Bike Radar via ::Core77; See also :Duncan Fitzsimons