Has Japan designed the world’s best bike shed? It’s not often something stops you in your bike tracks. But a spectacular “bike tree” invention from Japan bowled me over when I was in Tokyo a couple of weeks ago. Fed up with bicycles locked to railings, piled on top of each other, blocking doorways and roads, a local council in the city installed the mechanical masterpiece. It’s basically an automatic storage system for cycles and operates with computer tagging of bikes and either storage in a building or a basement structure. There are a number of locations where these bike trees are now in place in Tokyo some hold 600-odd bikes, others more than 6000. The concept came from the massive Japanese steel company JFE, whose engineering works division first started them in 2007 but are now spreading. The idea is quite simple, although no doubt the technology is fiendishly complicated. Bike owners who want a secure parking spot must register and pay a monthly fee 1800 yen (around £12 a month) and students get discounts. Bikes are fitted with a small electronic tag. When the bike is placed into the ruts of the bike tree machine, a sensor logs the owner’s details. A mechanical arm then emerges, pulls the bike into a cylindrical well and stores it at high speed in a free location. To retrieve the bike, the owner swipes a card through a reader and the bike is plucked from racks and brought back down or up if it’s a basement design to earth. The process of retrieval normally takes 15 …