While preparing for post-apocalyptic travel across the barren wastelands of what was once your hometown, you'll need a bike that won't become useless after the first flat tire. YouTuber user The Q has a solution: making functional tires out of tennis balls.
Note that there's a lot of prep work that you'll want to do before the downfall of the civilization and regular electrical power. The Q made small rings of PVC pipe and used them to mount the balls on the rim of the wheels. Attaching the rings required the construction of a custom jig that drove balls inside the rings without rupturing them.
The finished product looks like a rough ride, but functional--at least enough to keep you ahead of the cannibals that have been following you on foot for several days.
-via Hack A Day