Adventure Bike Rider Forum

crf250rally rear

I've got a problem with my rear tyre. I've got a mousse fitted ..
a Wise mousse, to a 110/100-18 maxcross IT. both are new and barely 20 miles old.
Ive fitted a new clutch and the bike has been standing for about a month, maybe less, waiting for the rain to stop.
When i came to do a test ride for the clutch, the rear end was bouncing/bumping like mad.

It felt like the mousse had deflated and the rim lock was thumping along the tarmac.
Is this even possible. ?????

could the mouse have spread inside the 120 rim?

I used to use mousses and they could shrink and soften a bit with age and mileage and they were always a very tight fit to get on in the first place (redbikejohn used to fit mine for me). Was the mousse big enough for the tyre or is the tyre maybe spinning on the rim?

I don't think its spinning .. but it feels a lot softer than when fitted ... and its only done 20 miles.
Someone on fb reckons it could be a flat bottom from standing in the garage ... I didn't know any different.

I #m taking back to the fitter tomorrow to see what he says.

I was just wondering what the hell could cause that?????

I used to take my nephew’s moussed FE250 for it’s MOT so he would drop it off to my place a few days before.
For the first mile or so it felt like riding on a flat tyre until it had warmed up a bit - twas ok after that.

It seems like I can feel the rim lock

the mousse was flattened at the bottom from standing in my shed. A good run out soon sorted it as it warmed.
The bike is now on a scissor stand lol.

Mousses generally are designed for racing and they are not supposed to be used for:
1. Longish road rides at speed.
2. Being left in a tyre compressed.
3. Sitting on the floor inside a tyre.
4. Not getting lubricated regularly.

Also worth noting is that they really do need to be matched carefully to the tyre. Many tyres differ in volume so might not be compatible with a specific tyre. Most mousses soften off differently with the gold standard being the mitchelin desert mousse.

So I think the idea mentioned above that the mousse has compressed at the point it was sitting on the floor is correct or it's popped off the rim from being too small for tyre.

I was wondering if it was too small .. being a 110/100 on a 120/80-18 rim?
but tbf, when it was fitted it was really good. its still new, in a new tyre.
My bad... i've never had mousses before ... its a `Wise` mousse ... but i may get a michelin next time? ..... or even go back to an inner tube ??/ see how it goes.

thanks for the input.
its raised off the floor now.

As a rule of thumb mousses and tyres should be 'matched' together not just in size but brand too. You are using a 100 which has a lot of volume compared to a 80 enduro. I remember using a mx tyre on my ktm and it would stretch enough at speed to rub on swingarm/mud flap compared to an enduro loop. While not many hobby (if any) riders will do it but mousses are designed to be removed after use, cleaned and lubbed! Yea I didn't.

I've considered fitting mousses, but haven't because:

a} they aren't street-legal and could invalidate your insurance

b) they seem more hassle then getting a puncture for occasional use.

I can see the point, if you are racing every weekend, regularly changing tyres to suit different tracks etc, but not for casual trail riding.

Decent quality inner tubes for me, please.