I switched my aluminum KHS from 2.1" knobbies and Rock Shox Indy XC fork to 1.5" street tires and chromo fork with identical axle-to-crown length. I want to convert to 700c/29er with disc brake one of these days since the fork has the tabs for it. I used the Nashbar rigid MTB fork that goes for $50, but it's almost always back ordered. It was back ordered when I placed the order, but didn't take too long for it to become available. But as soon as it came in I looked and it was back ordered again. Must be popular.