Having recently arrived in Dublin, we note a significant number of bicycle frames chained to

Having recently arrived in Dublin, we note a significant number of bicycle frames chained to things, but missing wheels, seats, handlebars, etc.  Tonight my son came to me and suggested "You know, I'm going to need some kind of a chain so that I can chain my bicycle just like all those other people did".

And I sort of think yeah, he will, but I'd rather we got one that actually worked and did not result in the frame being left chained and abandoned.

Does anyone have recommendations for what chaining device we should get, and how we should use it to make sure that doesn't happen?

Thanks.