大象传媒

Fixed gear bikes are the current trend in cycling, taking big cities by storm. The trend started amongst delivery people but has gone mainstream. In San Francisco, there are a number of workshops dedicated to them - the programme visits one of them.

Also on the programme: The Dutch architect planning an artificial archipelago in the Black Sea, shaped like Russia. Plus, a look at the new slide projectors that are so small they'll fit into mobile phones and personal devices.