one of my buddies let me borrow his 400ex for the a week or 2 so i told him i would fix it if something messed up. so today was my first day riding it and the axle bearings start popping and stuff so i had to ride about 10 miles all the way home on bad bearings. i have a set of atc 250r bearings and a set of 300ex bearings will either of these work?

 

The 300ex bearings will work. Aren't the 250r bearings the same too?

 

I believe the 250r bearings are the same, not sure about the 300ex.

 

300ex bearings are the same