- Take off one of your rear tires
- Pick it up and roll it around in the air near your ear
- What do you hear?

I hear stuff rolling around inside my tires !! What could be in there? This is first time I have heard of something like this.

 

i dun have a z400, but i have heard this in my old 300ex tires, i just thoyught it was a BB or pellet, cuz the guy i bought it from had hole plugged

 

There are lots of little things inside rolling around.

 

this might sound far fetched, but maybe its like pebbles or something from when the tires were being put on the rims? sounds hella far fetched to me, but im sure the more expierenced people here can come up with a cause for it...

 

Take it to a tire store and have it dismounted. That way you will know for sure what it is.

 

My rear tires (300EX) does the same thing, and they have never been pluged.

The day I got my 300 home I rode it around for a while, parked it at the shop and was checking everything out and noticed the left rim was put on backwards with the valve stem faceing in. When I took it off to turn it around, first thing I noticed was how light the tire\rim was, the second was something rolling around inside. 6 months later the axel bearings started popping, when I took the right tire off it also has the little something rolling around.

Wonder what it is? It must be rubber cause you don't hear it when it hits the rim.

Later

 

It is probably material from the inner surface of your tires that has been knocked off and is now coagulated into little *****. I had the same thing happen to my 400EX. Interestingly, years ago when I was running Dunlop competition radials on my autocross cars, they did the same thing!

 

It must be a radial thing. My other tires on my other quads don't do this.

 

take the air out and break the bead. something is obviously in there. either dirt or someone was tryin' to be funny when they mounted the tire.

 

I'll tell the dealership to check it out when I take it down for my warranty work.