The 02-03 chassi is better in all regards. Just compare the two frames (visually) and you will see the beefier/stronger construction of the 02-03. Look at the rear, upper mounting for the engine and the drop down sections where the swing arm bolt goes. Being able to tell any difference between the suspension bits and braking components is nearly impossible (though yamaha suggests they are better). Forks are shorter on the 02-03. The offset for the triples is better on the 02-03 aswell.