The biggest grade in Percy warner is 12-15% at about .4 miles. It is a short steep sprint of a hill in the 11 mile loop right after you descend passed Harpeth golf course. If you want some good climbs try Theta, Poplar Creek Rd, or McCrory Lane (climbing from the highway 70 side to the highway 100 side). Also the climbs onto the Trace are pretty good. One more is up Old Charlotte Pike. Start at Old Hickory and Charlotte. Take Old hickory to Old Charlotte and turn left. You'll hit a 1 mile climb that sucks bad. A final one would be the climb from River Road up Hwy 249 out in Pegram.