Hiked Peters Canyon with my son (3.3 miles) and decided to bike it too in the opposite direction (9.8 miles); my first time on SPD. Had to walk one short downhill segment with multiple more or less longitudinal ruts that looked just wide enough to eat my wheels and tires. Walking in SH-RX600 is much more precarious than trail runners! Don't know how cyclocross people run in them.