I looking for some information on replacing the fork on a 2002 Trek 6700 mtb. The bike came with a Rock Shox Duke which has turned out to be a huge POS.....looking to replace it with a Marzocchi Marathon S, with 105 mm of travel. I believe the max travel on the 2002 Duke is 100 mm. The guy at the bikeshop today #1 didn't really know that much about forks but kinda had to help us because there wasn't anybody else who could; and #2 totally freaked us out by saying we had to get something no bigger than 80 mm because it wouldn't work on the bike and would void a warrenty, blah blah blah. I guess my question is how much max travel is really going to affect the geometry of the bike? Will 5 make a huge difference or could you go higher? Also, if anyone could recommend a possibly different/better fork than the Marzocchi, I am open to suggestions. The only stipulation is we are trying to make the purchase before the end-of-the-year sales are over! This is strictly for a hobbiest, there will be no racing or dropping off cliffs done on this fork! Any help is appreciated!!