can i use 10s?

Im goin on my first dune trip pretty soon, and im gettin new tires, but what i was wonderin is... will ten inch rims bolt onto my 400ex, cuz i know i have nines, but most of the sand tires are eights and tens

Yes they will with no problem,,,,where ever you order them from will ship you the correct rims as long as you tell them what type of bike you have, the size of the rims should be 4/110 I believe. ,were you gettin em from.,,,,Oh and enjoy your trip to the dunes,,I've never been so I'm always a jealous east coast rider..