Your glaring error has already been pointed out twice. To reiterate, cut out Torreon and Monterrey and go south to Durango. When you route through Durango go through Santiago Papsquiaro. It's more interesting than the route directly south from Parral. Give me a should if you want to meet up.
Definitely substitute Guanajuato city for Queretero and look into the pyramids at Teotihuacán. They are just off the highway.
You might consider going south from Fresnillo, Zac to Guadalajara and getting to Mexico City through Michoacán. You will miss out on some culture, but the riding is better. Depends on what you are into.
Also, I wouldn't back track just to go to Hermosillo. IMO there is not much to see there.
SR screwed with this post 06-02-2013 at 02:38 PM