I want to to replace the OEM 63mm suspension fork on my Trek 820 with a rigid fork but the two cheep ones are rated to be correct for 85mm. Nashbar sells a carbon fiber fork for a hundred fifty bucks that is for" forks with less than 80mm of travel." but for less than the cost I can get a Rock Shox Dart 2. The carbon fork o rht e Dart would cost TWICE what I paid for the bike, so I'm hoping some one will say that i can replace with the 85mm correct fork.