Bicycle Tires 101: Inner Tubes
There is a debate amongst bicyclists surrounding various aspects of the tires we run on our bikes. Some argue that running latex tubes are better than butyl tubes, and others argue that running no tubes at all (using tubeless tires) is the best solution. In reality, it depends on the uses for the bicycle, and the environment the bike will be used in.
What is an inner tube? In simple terms, an inner tube (or "tube") is a donut-shaped balloon inside some bicycle tires. The inner tube is what holds the air inside of many bicycle tires. On this page, we will discuss the history of inner tubes, and the two types of inner tubes - butyl and latex tubes, along with their pros and cons.
A History of Tubes
The first pneumatic tire was simply an inner tube, without the tire casing. John Boyd Dunlop used a sheet of rubber on his son's tricycle to provide a better cushioning in 1887. Later, Thomas B. Jeffery created the clincher rim, which provided better puncture protection and help the tire on better.
Early tubes, used in bicycles, automobiles, and other things containing a tire, were made using natural rubber. This rubber, known commonly as latex rubber, was harvested from rubber trees in countries such as Sri Lanka and Indonesia, and other Asian and South American countries. The rubber was then molded into tubes. The manufacturing process for tubes at this time was fairly simple, but worked well. Tubes were commonly patched several times, especially during the Great Depression.
However, World War II caused rations on natural rubber, as it was a commodity produced in finite numbers. This ration caused synthetic rubber, later known as butyl rubber, to be developed for the civilian market as well as military use. Tires and tubes were patched numerous times during the Great Depression and World War II to avoid purchasing a new tire, and most pictures from those eras reveal bald tires on most cars. My grandfather can remember driving on bald tires in his 1931 Ford Model A Coupe, his first car, and can remember having holes in the tire where the tube should show through. He can also remember patching his tubes numerous times.
The 1950s brought about tubeless tires, which became commonplace on automobiles. By the 1960s, tubes and automobiles distanced themselves, and by the 1970s most cars on the road had tubeless tires. Tubeless tires dominated the automotive market, except in niche markets such as drag racing cars and offroading vehicles.
However, tubes still held their place in tractors, motorcycles, dirt bikes, heavy duty applications, and yes, of course, bicycles. Tubeless tires did not come on the scene for bicycle applications until the 1990s, and were an expensive solution to running tubes.
Butyl tubes dominated the inner tube industry since World War II. Since they are made of synthetic materials, they are cheaper. They were, in turn, much more affordable for the masses, and found their way into automotive, agricultural, and bicycling markets. You may have also seen them outside of tires, floating in pools, ponds, and rivers, since tractor, agricultural, and automotive tubes are often big enough to allow a person to use it for tubing. You can also use them for snowtubing.
Butyl tubes hold air much better than their latex counterparts. However, they don't hold air as well as tubeless tires. Butyl tubes can be found for most tire sizes, featuring both styles of valves (Schrader and Presta.) Butyl tubes offer greater puncture resistance, and have a greater sidewall thickness. Thus, tires with small holes can safely be inflated with a butyl tube, although this adds an opportunity for punctures and blowouts.
Butyl tubes, however, are heavy. They are heavier than their latex and tubeless counterparts. However, for most bicyclists who do offroading, trail riding, and general purpose riding (i.e. street riding), the weight difference is almost unnoticeable.
Butyl tubes are easier to install, and come in a variety of weights. Light duty tubes are the lightest of butyl tubes, although still weighing in heavier than most latex tubes. Light duty tubes offer less puncture resistance, but are a cheap alternative for racers to expensive latex tubes. Normal duty are usually the most used, as they offer fairly decent puncture resistance, sidewall thickness, weight for a fair price. Normal duty tubes are the cheapest of the bunch. Heavy duty tubes are heavier, but have a thicker sidewall thickness. Thus, a greater puncture resistance. You will often find heavy duty tubes in dirt bikes and off-road applications, where punctures are common. A heavier duty tube will also work better with a tire which has a hole in it, due to the increased sidewall thickness.
Butyl tubes can also "stretch" better, which can mean that they can be used in a variety of tire thicknesses without worry. For example, a tube which can fit a 26x1.50 tire will typically fit a 26x2.40 tire without much problems. This elasticity can also add uses for the tube after it has been patched enough times, or the tube finally bursts. Such uses include rubber bands, and other things. People have also made clothing out of recycled tubes.
Most butyl tubes have a guide line printed into them, typically in blue or white ink. This helps ensuring the tube doesn't become twisted during installation.
Latex tubes, however, are usually liked better by racers. Since latex tubes are thinner, they are lighter, which decreases the overall weight of the bike. Some bicyclists will argue that "Latex wins races."
Latex is the same material that gloves found in medical and food handling industries are made of. The latex inner tubes are usually not any thicker than a typical glove. Latex tubes can be bought in a variety of colors, including green, tan, or pink. (Butyl tubes just come in one color: BLACK.)
Latex tubes are made of natural rubber, or rubber harvested from rubber trees. This means the tubes are ultimately, more expensive than butyl tubes. However, most bicycle racers argue that the performance is enhanced enough to make the investment worth it.
Installing latex tubes is similar to installing a butyl tube, although everything has to be much more precise due to the lower sidewall thickness of latex tubes. Any hole, no matter how small, in the tire casing will spell doom for your expensive latex tube. The bead will also need to be seated properly, much like butyl tubes. Latex tubes are notoriously known for finding their way through even the smallest holes in any tire, and popping.
Latex tubes offer increased performance, and decreased weight. However, latex tubes are commonly found only in races, as the puncture resistance isn't as good as their butyl counterparts. Butyl tubes are found mostly in offroading, trail riding, and general purpose riding environments as they offer increased puncture resistance, cheaper price, and don't affect performance so much that many bicyclists will notice the difference. However, it depends on your use of the bike, which dictates what tubes to run.
Laytex tubes also loose air quicker, requiring inflation nearly daily. This is because latex is more porous than their butyl counterpart, and thus loose more air in a certain period of time.