
This, probably, is to regular analog bikes what they are to motorbikes.
It's made entirely out of wood and glue (and some paint). Not a bit of metal, plastic or rubber, not even a nail or a screw. Bearings are lignum-vitae and the saddle only looks like leather.
They set a world speed record with this, not really much of a problem one would think as no one had set any record for an all-wood bike before, but I've just seen a tv program about it and they managed to break both prototypes in the attempt and not even switching parts around helped them much.
In the end, they managed one complete run in either direction, 11.25 mph.
I like the idea of that enormous plywood cog, but I would have gone for shaft-drive. Or maybe a long crank-arm arrangement, similar to the running gear on a big old steam locomotive.
And used a hardwood, but finding large enough hardwood pieces for something as large as they did end up making is probably tricky these days.
More info:
http://www.splinterbike.co.uk/