I ran this trail about 4 years ago in the early summer. Unless you are going to try to get way off the main trail (like ascending the Kaiparowits Plateau from the East), you won't need 33's or a rear locker. What limits you is how lately they have had a road grader down there to smooth out the washboards. Since the road spans two counties, there can be a big difference in the northern and southern sections. I would really like to do it again, but I need to see if my Heep holds up on the other side of the lake (Emigration Trail) around May 3 to 8 and then whether we get out of Lost Wages with our shirts and both kidneys. Then, I can decide.