Guidance on tubes in tubeless road tyres
Tubeless tyres in good condition, both new and retreads, fitted to the appropriate wheels and operated correctly, do not need inner tubes however there are some circumstances when it is useful to use a tube. When tubes are fitted, it is important for the user to understand the potential drawbacks.
- When a tubeless tyre is punctured, the penetrating object is gripped by the inner liner (the built-in tube) and thus air loss through the penetration will be gradual. By contrast, when a tube type or a tubeless tyre fitted with a tube is punctured, once the tube is penetrated, air loss will normally be sudden. In this case, air will rapidly escape through the valve hole in the wheel and between the tyre beads and the wheel which, with a tube fitted, no longer provides a hermetic seal. Sudden pressure loss in a tyre can result in bead dislodgement and a loss of vehicle control.
- When a tube is fitted to any tyre, it is important that the inside of the tyre is carefully examined to ensure that there is no feature which could cause premature tube failure due to cuts or chafing. Such examples are:-
- Any tire manufacturer’s paper or plastic identification labels must be removed and label indentations buffed smooth.
- Damage to the inside of the tyre, possibly due to a previous penetration or repair can lead to chafing of the tube and subsequent failure.
- The increased thickness of the tyre / tube assembly can cause running temperatures to increase and could under prolonged conditions cause premature tyre failure.
Not withstanding the potential hazards, there are circumstances when the use of tubes may be recommended. The following points should be noted:
- Inner tubes must be fitted to all tyres that are NOT marked as “Tubeless” and to all tyres marked as “Tube Type”.
- Always use a new tube in a tyre with matching size marking.
- NEVER install a non-radial tube in a radial tyres
- Inner tubes should also be used:
- Where tubeless tyres are fitted to non-safety wheels or multi-piece wheels.
- Where tubeless tyres are fitted with wire spoked wheels where air could otherwise escape through the spoke holes in the wheel.
- Inner tubes should not be used as a means of repairing a puncture to a tubeless tyre, as a proper repair should be carried out to retain the tubeless properties of the tyre.
- The fitment of tubes to tyres of 65 series and lower is not recommended.
- If correct size tubes are not available, an alternative size tube should NOT be used.
Wire wheels, multi-piece wheels and some single piece wheels designed for tube type applications CANNOT be used as tubeless fitments and the use of a tube (regardless of whether the tyre is “tube type” or “tubeless”) is ESSENTIAL FOR SAFETY. Always use tubes in such fitments.