
Bike tubes have been used for decades as the primary means of keeping a bike tire inflated. They are essentially donut shaped balloons that are placed inside the tire. Air is pushed into the tube via some form of valve.
Most bike tubes today are made from Butyl rubber; however, this wasn’t always the case. Latex rubber was the most commonly used rubber for inner tubes before World War II, but as it became a hard-to-find commodity during the war, Butyl became the substitute material of choice. It was so successful as a substitute that most tube manufacturers kept with it even after the war was over.
Bike tubes are not required for all mountain bikes. Tubeless tires are becoming increasingly popular due to their ability to withstand “pinch” flats. Because these tires have a thicker sidewall, they are less prone to leaks due to aggressive riding.