Try putting better tires on the Avalanche. Kenetics are a good, cheap tire that hook up fairly well. I have a buddy that has a GT avalanche 2 with an All mountain 3 fork and Kinetics.

http://putfile.com/pic.php?pic=6/15620083360.jpg&s=f5

That's my Trek Bruiser in that pic. It cracked. I'm getting a new frame next week.