|Marcel Duchamp, Bicycle Wheel, 1913|
As the story goes, Ben Franklin was speaking to a Revolutionary assembly. He held up an arrow and broke it in half. Then he held up a bundle of arrows and tried to break it, and couldn't, and it was something to do with how if they were united they'd be unbreakable. That's just because the bicycle wheel hadn't been invented.
If you pick up a bicycle spoke on its own, you can easily bend it with one hand. The rim is a bit sturdier, but you could bend the rim fairly easily if it hasn't been built into the wheel. Once the various parts of the bicycle wheel are combined and tuned properly, it's a wonder. Together these parts that are weak on their own can now withstand tremendous impacts with ease.
How the wheel works is not what you'd logically expect. The spoke attaches to the rim and to the hub and it's under tension. Every spoke is pulling the rim towards the hub. So when the rider is on the bike, the ground pushes up on the wheel and tension of spokes at the bottom reduces. When you're riding, you're actually suspended by the spokes at the top of the wheel, while the spokes at the bottom are relaxed and able to absorb impacts.
Look at the wheel Duchamp displayed and compare it to one of today. The design is very similar to the ones of today. Every so often they'll try something new, like a disc or a blade, and it'll be around for a little while before people realize they really couldn't improve on perfection.