on my 300ex the right front brake rubs alittle causing it to squeak while riding slow or pushing it.my friend's 300's do it aslo.is there anyway to stop it?it gets really annoying.

 

The same thing was happening with my 250X a few days ago. It lasted about 4 days of riding. Don't worry, you just have some mud or water in the brakes which cause it to sqeak. It will go away if you drive it in dry weather a couple times and give it a chance dry out.