As it turns out, bicycle chains are not a bad way to chain up your bicycle (or cart)!
A bike I rented in Hampi had a very neat lock on it. It was so subtle that I didn’t notice it at first and actually went back to the shop to ask for a lock, at which point the shop keeper showed this neat device to me.
A simple metal bracelet which wraps around the rear wheel. When the metal lever is pushed down, a metal bar slides through the spokes of the tire, so the tire can no longer rotate.
A simple, elegant bike lock. Surely it most be cheap to make. Ideal for a bike rental agency, where the theft you’re looking to prevent comes in the form of opportunists waiting outside popular tourists sites.
Sure, it does not secure the entire bike and a thief could steal then entire bike or use tools to disassemble parts, but since those are less opportunistic thefts and more preplanned, I think this lock is well suited for the work it is assigned.
With a simple turn of the key, the tire is released, and I pedal on.
A random stack of chairs chained to a lightpost. Who sits here so often that they want to have chairs and are willing to leave them behind when not in use?
Four chairs, one lock. Which of the four people who sit in these chairs has the key?
With no tires or seat, will the owner collect what is left of this bike? Perhaps the owner lost the key and came to take anything removable and of value off the bike? If the owner doesn’t take it, who will remove this bike from the post it is locked to? How long will it stay there? Does an abandoned bike frame count as litter?