I jeeped your loop several years ago to see if it would be good for riding (I live in Mesa too). I went counterclockwise, first going by Tortilla Flat, then Roosevelt Lake before getting to the offroad stretch that runs along the north side of the peaks and on down to Highway 87. Like you were wondering about - there are many side roads on the offroad stretch. It is apparently rare for someone to even drive the entire stretch, as the side roads were often more established. I had a good map with me, but many of the side roads were not on it, making navigation difficult. I recall, there were two splits on the downhill side where it was a 50/50 guess to find the correct road back down. I guessed correctly, and felt very lucky. The road condition was not too rough, but some sections were very steep. I remember there was one section on the downhill side where my Jeep was sliding in four-wheel-low. If you go back, I reccommend taking a map and GPS. Also, if you have an SUV, consider driving the loop first so you will know where to go when riding.