
A bike chain was actually unnecessary for the first few centuries of cycling. The very first bikes didn’t even have pedals, they were walked up hills and ridden down hills, level terrain was something of a mix between walking and riding, similar to skateboarding today. The frame lacked anything that would be meaningful to attach a chain to.
Even after bikes got pedals, it was a long while before they got a bike chain. The first pedals were put on the front wheel, in front of the rider. After that, the rider was placed directly over an enlarged front wheel in the high tower bicycle. It wasn’t until the safety bicycle that a bike finally got a chain.
The safety bicycle was the first bicycle to center the pedals under the rider, and away from either wheel. The bicycle connected the pedals to the rear wheel via a bike chain. Since the inception of the bike chain, little has changed about it. The links are secured differently now than they were in the first rendition, but the concept and structure is largely the same. The biggest thing to watch for when buying a chain is whether or not it will be long enough for your gear and frame setup. Many bike shops will sell chain by the foot and custom fit one to your bike to save you from having to measure it yourself.