http://www.oldbike.eu/museum/This is one for a rainy day. Lots of interesting bikes in great depth with lots of pictures and background material. Interesting from a social history perspective as well as a technical one.
There is also a lot of material showing how bicycles and tricycles evolved motor assistance and then developed into motorcycles and cars.
If you are interested in electric assistance it also shows how this is the latest phase in the evolution of cyclemotors that were last popular, but for different reasons, in the post war period.
If you ride a Thorn with hub gears, fat tyres,mudguards, sturdy frame and leather saddle you'll know these things are timeless and can see how they evolved.
Enjoy
Ian