haven't been to Moab since June, but have ridden a few trails there. I doubt Porcupine is ridable this time of year. Sovereign is a pretty fun XC trail. I like Amasa back a lot but not sure if it is ridable right now. Slickrock is classic.
Sorry I can't comment on what is ridable, i'm sure others can, but amasa back is a really fun out and back with incredible views, fun drops, technical ledge climbs, and some danger factors as well. not sure what you want to ride.
The Amasa Back trail (ascends from the Colorado River just west of Moab, climbing up onto an outcropping of rock surrounded on three sides by the Colorado. The trail is a rocky Jeep trail with ledges and drop-offs, and is for advanced riders. As an out-and-back, the trip is 10 miles. Vertical climb is 1050 feet. The lower two miles of the trail is a tricky series of ledges and rock challenges. Clearing the multiple rock obstacles will test your skills on the way up and again on the way down.
On a 6" travel bike the ledges feel like a pillow line on the way down but really do make for a fun time on the way up. I normally don't LOVE climbing, but had a lot of fun on this one trying to make it further than anyone else on any given climb. Some seem impossible but aren't, others might be.
