Mousse tire inserts: fitment, used mousses and mousse lube

1983the year Bib Mousse was bornMichelin's foam insert has been winning rally, enduro and motocross races ever since.

18months from factory to first rideMichelin wants a Bib Mousse in its first tire within 18 months of manufacture.

6months of riding once it's fittedMichelin's window after first fitting. Motocross eats them faster than enduro.

Foam, not air

Goodbye, flat tires

Somewhere out there is a cactus spine with your name on it. Run a tube and it finds you a long way from the truck. Run a mousse and you ride right over it, because there is no air in there to lose.

A mousse is a ring of foam that sits between the rim and the tire, right where the inner tube used to live. Michelin's Bib Mousse is the classic. It is lighter than a reinforced tube, rides like about 13 psi, and was made for rally, enduro and motocross.

Mousses have one big enemy, and it's heat. Keep that in mind. It comes back later, carrying a bag of juice.

Read the sidewall

Fit the tire, not the bike

A Michelin Starcross 6 front tire on a black rim with a wave brake disc and orange fork — Everything you need is printed on the rubber. Photo: KTM.

Your mousse shopping list

The tire: brand, model and the full size off the sidewall.
The wheel: rim size, front or rear.
The chart: the mousse maker's fitment guide for that exact tire and wheel.

Two KTMs in the same garage can wear two different tires, so the bike's name alone won't pick a mousse. Michelin lists which Bib Mousse goes with each of its Starcross, Enduro and Desert Race tires.

A KTM rider leans into a dune, throwing a wall of sand — Sand, rocks, cactus: nothing to puncturePhoto: KTM

Pre-loved foam

Every used mousse has a story

A used mousse can be a great deal. Get its life story first: the exact model, the manufacture or packaging date, when it was fitted, which tire it lived in, how it was ridden and where it was stored.

Then hold it up to Michelin's own numbers for Bib Mousse. First fitted within 18 months of manufacture, ridden within six months of fitting, stored cooler than 86°F where you can and never above 104°F. A motocross mousse wears out faster than an enduro one.

A cheap mousse is not always a young mousse. Buying a wheel and tire set? Find out what's inside before you count a mousse in the deal.

Mousse day

The wrestling match

Fitting a mousse is the closest thing in moto to wrestling a greased pig, and Michelin's install guide reads like a battle plan. Rim tape over the spoke nipples. No valve in the rim, because there's no air to put in. Gel inside the tire, half a tube up front and a full tube out back, kept off the beads so the tire won't spin on the rim. Lube on the first bead and on the part of the mousse that meets the rim.

Then come the levers, a foot apart, one after another, until the bead gives up. A shot of about 50 psi through a tubeless valve pops the beads into place. Before a fast stage, Michelin says to warm the tire and mousse up at a moderate pace. Michelin rates a tire with a Bib Mousse inside to 80 mph, which is plenty in a sand wash.

That's a lot of slippery steps. Which brings us to our favorite part of the story.

The hero of this story

Meet Mousse Juice

Slicker than moose snotMousse Juice, describing Mousse Juice

Our own mousse lube

Remember heat? Michelin says to gel a Bib Mousse every time it goes in or comes out, new or used, to keep heat from cooking it. That's the job Mousse Juice was born for.

Slippery: wrestling a Bib Mousse onto the rim turns into a walk in the park.
Cool: keeps mousses from melting down in the heat and lasts longer than the rest.
Kind to the bike: rust inhibitors and a safe, non-toxic formula. Still not a snack.
Easy: a light golden paste that washes off with water.
Plenty: it comes in a 5-pound bag.

Illustration of a cartoon moose dripping golden juice beside a giant knobby tire — The mascot, doing quality control. Art: Mousse Juice.

Illustration of three moose riders in riding gear eating tacos at a table in the desert — Mousse day done, taco timeArt: Mousse Juice

Baja-tested

Born where the cacti bite

Mousse Juice earned its stripes in Baja, where the trails are rough, the cacti are sharp and the dust gets into everything. It came through all of it, and we figure that's the toughest test a mousse lube can get.

It lives at Adventure Baja, our Baja riding and moto business. Want to put your own mousses through the same test? Our Baja motorcycle tours story has the rides.

It can't go flat