Ditch tubed tyres in favour of mousse to make punctures a thing of the past
Paying for convenience
At over £250 for a pair of Michelin Bib Mousses, they’re hardly a cheap investment, especially given they may need replacing after just one and a half years.
Dakar heroes are well known for using puncture-proof mousse tyres but they are becoming more and more popular with everyday off-road enthusiasts. So what are they and how exactly do they work?
A flat is the last thing you want when you are miles into an off-road adventure – which is where the Bib Mousse (named after Michelin’s mascot, Bibendum) comes in. Effectively a foam ring, it takes the place of an inner tube and provides structural rigidity, as well as impact absorption but isn’t road legal.
Some manufacturers, such as Italian brand Risemousse, have attempted to create such a product that could be deployed effectively (and legally) on tarmac, but these never gained much traction.
So what exactly is a mousse? Not to be confused with the tasty chocolate dessert, it is a “foam infill that takes the place of an inner tube to fill the internal volume of the tyre,” says Paul Daley-Smith, owner of Enduro Tyres (Michelin tyre importer and distributor).
While this may not seem high tech, modern mousses are the product of decades of development. First pioneered for rally-raid events by Michelin in 1983, mousses are now used at the top level of off-road racing the world over, with Michelin holding 36 victories at Dakar since their inception.
A modern mousse is constructed using a honeycomb butyl (a type of rubber) foam structure, with multiple closed-cell pockets filled with nitrogen. Covering this is a smooth, low friction ‘skin’ that is designed to allow movement as the tyre flexes under load.
Once installed, the system totally removes the chance of suffering a puncture. But that’s not all, and thanks to the ‘dead’ feeling they provide, riders enjoy increased traction too with their wheels less likely to deflect from undulations on the trail.
Feeling the pressure
That’s all well and good, but there are a couple of drawbacks. Friction is the enemy of the mousse and for that reason trouble can occur when the temperatures start to rise.
Daley-Smith told MCN: “The system shouldn’t be used in temperatures above 40 degrees or higher than 80mph.” Doing so can lead to overheating, causing rapid degradation or even failure.
Also, a mousse also cannot be easily adjusted for feel in the same way a tube can be. Fresh out the box, they provide an equivalent support of about 13psi, but this softens with wear.
