Downhill Mountain Bike Brakes
It is true that gravity will eventually bring everything to a grinding halt. But, if you are flying downhill on your mountain bike, who knows when that time may come? Brakes are an essential element to any and all downhill mountain bikes: to not have brakes is to ask for severe injury or death. Brakes add an element of safety and control to downhill mountain biking.
Brakes on a downhill mountain bike allow the rider to control the speed at which they travel. It allows them to control the tension between their wheels and the ground. When mountain biking on downhill trails, there are sudden obstacles or obstructions taht one needs to be able to stop point-blanke for, such as rocks, roots, and cliffs that lead to nowhere besides fresh air. Brakes are the only component of a bicycle that allows a cyclist to do this.
Brake systems all operate in the same basic way. A mountain biker will squeeze the brake lever on their handlebars when they want to slow down. This lever is attached to a cable, which is then attached to either the rear or the front brakes of the bike. (Most downhill mountain bikes have two brake levers - on on each handle. Each brake lever controls either the rear or the front wheel of the bike). The cable that runs from the lever on the handlebars will pull two levers that frame the mountain bike's wheel together. Attached to these levers are two brake pads - those brake pads will squeeze the rim of the wheel, provding enough friction to stop the motion of the mountain bike.
There are two types of brakes that are available for downhill mountain bikes - rim brakes and disc brakes. Read on for particulars about both!