1. The earliest bicycles didn't have pedals. Invented in Germany in 1817 by Karl von Drais, the first bicycle (called a "dandy horse" or "running machine") was made of wood. Riders moved by sitting on the frame and pushing their feet directly against the ground!

2. The famous "Penny-Farthing" bicycle had a front wheel higher than a person. In the 1870s, bicycles were built with giant front wheels up to 5 feet tall because larger wheels meant higher speeds with every turn of the pedals. They got their name because the huge front wheel and tiny back wheel looked like a giant British penny coin next to a tiny farthing coin.

3. Bicycles helped lead to the invention of airplanes. Orville and Wilbur Wright (the Wright Brothers), who flew the world's first motor-driven airplane in 1903, were original bicycle mechanics! They ran a bicycle repair and sales shop in Dayton, Ohio, where they used bike parts, steering concepts, and lightweight metal frames to build their early gliders and aircraft.

4. There are more than two billion bicycles in the world. That is more than twice the total number of cars on Earth! Over half of the world's bicycles are in Asia, with China alone holding hundreds of millions of bikes.

5. The longest tandem bicycle ever built held 35 riders. Built in the Netherlands in 2015, this record-breaking bicycle was 135 feet long (longer than two city buses parked end-to-end!) and required all 35 cyclists to pedal together at the exact same speed to keep it moving.

6. Bicycles are the most efficient form of human transportation on Earth. A person riding a bicycle uses far less energy to cover a mile than someone walking, running, swimming, driving, or flying. In fact, riding a bike is about three times more energy-efficient than walking!

7. Over 100 million bicycles are manufactured every single year. That means around 270,000 brand-new bicycles are produced worldwide every single day to supply commuters, mountain bikers, and kids learning to ride!