All you need to know about butyl inner tubes

All you need to know about butyl inner tubes

The most common form of inner tubes found today, are made from butyl rubber, which is a synthetic elastomer made by combining isobutylene and isoprene. This material is an excellent choice for inner tubes, as it exhibits quite positive shock absorption characteristics for durability, while returning low moisture and gas permeability, to maintain internal pressure. These tubes are known for their classic black color, durability, and low cost, which provide an effective solution for a large population of users.

For these reasons, butyl tubes are widely used commercially. For example, these are most likely the tubes found as original equipment on your new bike, or that a shop may use to repair a common flat tire. In the event of a puncture, butyl tubes are easy to patch using an inexpensive patch kit, which is readily available at bike shops, as well as most hardware stores. These patches are applied using rubber cement, and have a similar elasticity to the tube itself, ensuring a positive repair.

Types of butyl inner tubes

As butyl tubes are primarily designed for utility, they come in a wide variety of sizes and wall thicknesses, further broadening their useful range of application. There are “ultralight” versions of butyl tubes, which feature a thin wall, designed for minimizing weight, and maximizing flexibility. Conversely, there are also “thorn-proof” butyl tubes, which employ a thicker wall, designed to minimize punctures. Then, there are also the standard replacement tubes, which are a happy medium of all the above traits. A further variation also includes a “self-sealing” version, which is most made from a standard butyl tube containing a liquid sealing agent, designed to automatically seal small holes.

Pros and cons of butyl inner tubes

Whichever the purpose of the needed tube, there will be a butyl rubber option, and in most cases, they will be readily available in your local bicycle shop. However, the simplicity and utility of using butyl rubber tubes does come with some limitations. First, butyl rubber is often not the lightest material for the intended purpose, and this weight is critical as it is rotating weight. In performance applications, this will likely to be a consideration, and is the reason that upgrading the system (via the use of performance tubes or by going tubeless) is so popular. Second, the ultralight versions of butyl tubes use a very thin wall thickness to compensate for weight, which then reduces their durability, whereby negating one of the key strengths of the material in the first place. Third, the level of elasticity of butyl rubber is slightly lower than with some other tube materials, which contribute to increased internal friction between the tube and the inside of the tyre, causing negative effects on rolling resistance in high performance use. Despite these relative potential high-performance limitations, the inherent utility of a standard butyl innertube is hard to beat for normal “everyday” use. If you are a city commuter, and you simply want a low-cost option for transportation, or if you are a mountain biker and prefer a thicker thorn-proof tube, butyl rubber innertubes are likely your best option. For these reasons, along with the low cost, butyl rubber innertubes have earned commercial popularity.