The Wright brothers invented the airplane in America. Did you know that they were bicycle mechanics? Well, what good is building your own airplane from scratch without using some bicycle parts like they did? I'm using a couple of chain sprockets for my manually operated landing gear. You can find chain sprockets on their first airplane too.
Orville and Wilbur didn't have supermarkets back in their day, and they didn't have access to shopping carts either. I am quite sure that if they did, they would have certainly taken advantage of using some parts for their airplane like I did. The tail wheel is from a shopping cart! It's cheap, and tough. It's also easy and economical to replace when worn.