Origin8 does a cross frame/fork set that takes up to 52mm tires, I've read



my search for a large old hybrid didn't pan out so well but I got hold of a 29er frame and wheelset for cheap and built it up with Big Apples - here's a pic of it first rolling - I've since replaced the temporary funny colored bits but don't have a newer pic


it's my first aluminum frame and first disc brakes - I did go with friction shifting and a B-17 though







I like the camelback specialized crossroads from the 90s too - not sure how fat the trek multitrack would take, but it was on my list



good luck goin fattier!