I definately recommend the Maxxis Razr 2's. I just bought a set for my 400ex and absolutely love them. I think they look tough and will bite on any kind of surface. I was debating between the holeshot XCR's when I bought the Razr's and I'm glad I decided on Maxxis. I have rode a few other quads with Holeshots and they are good tires (don't get me wrong) but I like the feel, handling, and look of the Razr 2's. That is my $.02 anyhow.