Trees and bikes, what happened next will have you doubting pedal power! Or maybe a hurricane blew by and deposited a substantial amount of bicycles in the willow tree along the 15th sideroad. This mystery may never be solved until they invent something like a series of tubes where you can look up stuff.
Okay, the internet exists and the bike tree is to support Pedaling Against Poverty. They have been up there for a couple of years, now it is probably just a pain in the butt to take them down, so what the heck, leave them up there. The house is up for sale now, the owners probably didn't like all the bikes in the neighbourhood.