Why I would rather change a mousse than lose a race weekend to a flat

Disclosure: Jeff has tested with Michelin, received Pirelli and Dunlop tires, received amateur race support from Dunlop over the years, and has a hand in his employer’s house-brand Artrax tires and mousses. The personal experience below is his; the care directions are manufacturer guidance. This is not a head-to-head test of every system.

The explanation that stayed with me

When I was testing the Michelin Starcross 6 tires with Michelin in Texas, they gave me one of the best explanations I have heard for running mousses. You can spend hundreds, even thousands of dollars on fuel, food, accommodation and everything else that goes into a race weekend. Then a flat tire can stop the ride you spent all that money to have.

That is my recollection of the point they made, rather than a word-for-word quote. It stuck with me because the cost of a flat is rarely just another tube. It is the missed race, the lost riding time and the frustration of doing all the preparation only to stop for something you could have planned around.

I have tested many of the best tires on some of the coolest tracks and terrain in the world, with some of the top riders in the world. I prefer the dead feel of a mousse on the track. Other riders want the response and easy pressure adjustment they get from air. That preference is personal, and I am not turning it into a claim that a mousse makes everybody faster.

My opinion is that anyone taking off-road riding seriously should try a properly matched mousse and consider it. Give it a fair ride before dismissing the feel. Compare it with the tube setup you normally use, on familiar terrain and before an important race. You might still prefer a tube, but at least the decision will be yours.

Where my opinion comes from

Michelin is not the only tire company I have spent time with. Pirelli sent me a set of its then-new motocross tires to test. I also spent time with Pirelli back when it worked with the JGR team, went to a U.S. MXGP with them and toured the JGR facility. Dunlop has sent me tires and provided some amateur race support over the years.

At work, I have a hand in our house-brand Artrax tires and mousses. That connection belongs in the conversation whenever I discuss them. I think there are great products across these brands, and Michelin remains my personal favorite, including for cars. That is my opinion from my own experience, not proof that one brand wins every comparison. The right product and the price for your application still matter.

The case matters for kids, too

I think the argument is especially strong for young racers. Who wants a child to miss the finish of a big race because of a flat? Families put a lot into getting to the line. Reducing one avoidable cause of a DNF deserves to be part of the preparation discussion.

That does not mean an adult-size insert belongs in every mini. MrWolf currently lists Lunar mini-front MBL1001 for 70/100-19 and mini-rear MBL2003 for 90/100-16. Those are specific examples of youth-sized options, not proof of compatibility with every 50, 65 or 85. Both listings showed out of stock when checked. Match the exact tire model, size and rim, verify the appropriate setup, and give the child time to get used to the feel. ^{[4] [5]}

The tradeoffs are part of the decision

The extra installation work, purchase cost and finite life are real. I would rather discuss them plainly than sell the idea that a mousse is maintenance-free. Installation takes technique and suitable tools. If you are not comfortable doing it correctly, use a shop that knows the system. A badly prepared wheel is no bargain, whatever is inside the tire.

Weight needs a fair comparison. Michelin describes Bib Mousse as lighter than a reinforced inner tube. So it is not accurate to say every mousse adds weight against every tube. Compare the exact insert with the actual tube it replaces, and include any different hardware. The feel can change even where the weight difference is small. ^[1]

A mousse removes the ordinary loss-of-air puncture problem. It does not make a torn tire, damaged wheel, worn insert or incorrect installation harmless. I want the puncture resistance without pretending the rest of the wheel no longer needs attention.

Storage and age matter

My rule is to put a mousse-equipped bike on a secure stand with both wheels off the ground when it is being stored. I would not leave it sitting on the tires for weeks. Nitromousse’s own installation instructions recommend that practice and warn that extended loaded storage can produce flat spots. That supports the habit; it does not establish that one afternoon on the ground ruins every brand of mousse. ^[3]

Michelin’s published Bib Mousse directions focus on temperature, age and lubrication. They say first use should be within 18 months of manufacture, and service is limited to a maximum of six months after first fitting. Hard use can shorten that considerably. Avoid prolonged storage above 30°C/86°F and temperatures above 40°C/104°F. Those are Michelin’s limits, not a universal timetable for all brands. ^[1]

Michelin also calls for progressive warm-up before fast use and fresh Michelin gel whenever a Bib Mousse is installed or removed. A stand cannot make up for excessive heat, inadequate lubrication or a worn-out insert. Follow the current directions supplied with the exact product, record when it went into service, and inspect it when the tire comes off. ^[2]

Count the whole weekend

I still see the choice through that Texas conversation. If a mousse suits the bike, tire and riding, its cost belongs beside the rest of the weekend budget. The point is to protect the riding time you worked and paid for.

For me, the dead feel is a positive and the flat resistance is a major reason to run one. You do not have to share that preference. But before deciding that a tube is the cheaper answer, think about what a flat would cost at the event that matters to you. Then choose the system you can fit, maintain and ride with confidence.

Keep reading

• Tubes, Bib Mousse, MousseBalls or TUbliss: choose the system you actually need
• Exploring Dirt Bike Tire Tubes and Mousses: Choosing the Right Option for Off-Road Riding