Tyre Inner Tubes

Modern tyre inner tubes are made from butyl rubber, which is a synthetic rubber manufactured to the special quality as required, unlike natural rubber which is porous and can leak under pressure.

Properties of Butyl rubber 

Butyl rubber has the following properties that make it ideal for use in tyre inner tubes: -

• Insignificantly low gas permeability
• Thermal stability
• Ozone and weathering resistance
• Vibration damping
• High coefficient of friction
• Chemical and moisture resistance than other rubbers
• Being less polar, butyl rubber is relatively difficult to bond

Concerns

Most cars since the 1970s were manufactured featuring tubeless tyres for various reasons among them safety. Statistics demonstrate that the probability of failure in a tube setup is higher than that of a tubeless assembly, the most common causes are: -

• Incorrect tyre and tube size match/fit
• Friction between the tyre wall and inner tube generating excess heat
• A puncture

Tubeless tyre technology omits inner tube thereby increasing safety. In a tubeless tyre, the tyre and the rim of the wheel form an airtight seal, with the valve being directly mounted on the rim. If a tubeless tyre gets a small puncture, air escapes only through the hole, leading to a gentle deflation. Conversely, in a tube setup, the tube could burst within the tyre, leading to instant deflation of the assembly which could result in loss of control of the vehicle. However, the "bursting" scenario is highly unlikely due to fact that the inner tube is inside of the tyre and will deflate at a rate proportional to the puncture hole size. In antique automobiles, made before the mid 1950s, the rims were never designed for tube type tyres, and an inner tube is required to prevent slow leaks notably at the bead.