I have one of these (from my limited knowledge I'd call it an XC bike) and I was looking to put some rigid forks on there. My current crown to axel height is around 480mm and all 26" rigid forks fall quite a bit short of this. However, the Surly Karate Monkey Fork is around 468mm, which isn't too big a difference. The thing is, it says it has removable cantilever mounts...is there any chance you can just move them a little lower? or if not, will disc breaks still work?