thanks bhkyte, that German bike is a very pretty thing indeed. It also looks incredibly light.

I'd love to show you my idea, but can't until i've at least finalised the initial design and spoken to a patent lawyer. It's rather more chunky than the aforemationed bike, which again is a result of it's eventual intention as a mountain bike.

I get what you're saying about 20" and 26" wheels and I realise that there will probably be an insignificant performance advantage, but I've kind of taken on the challenge of producing something of identical proportions and geometry to a regular mountain/urban bike. The wheels themselves will reduce in size too. The folded package will be about 900mm x 300mm x 300mm including the wheels. I'm aiming at backpack size.