We drive that way frequently for hikes - there is now a wide shoulder almost the entire way from Mesa to Payson that I would not hesitate to ride on with a buddy or two; I would not personally do this ride alone due to the remoteness of the area. The way back is a different story as there are long segments with no shoulder as others have mentioned. Normally this would not stop me - recently I did a Phx to Tucson ride where long segments had no shoulder and we did fine. Just be prepared for drunkards pulling trailers/boats and semis pulled over on the shoulder. In the Mt. Ord / Matazal area north of Sunflower your bike speeds on the curvy descents will be near car speeds. I would avoid rides like this on weekends and especially holidays as everyone and their mom are escaping Phoenix for the camping towns.