It's going on a mid-90s frame. The bike originally had a suspension or rigid fork version. I've got the rigid, but I'm pretty sure the frames were the same geometry-wise. I've been using a Manitou suspension fork from ~2000 that's an 80mm fork. The actual travel seems to measure ~75mm. Handling is perfectly fine with that fork. It's completely worn out, though, and the inners of the fork have a pretty good wiggle within the outers. Ideally I'd like to stick with an 80mm fork, but 100mm would probably be alright too, I think.