I am going on a weeklong trip next month (Tucson AZ to the Grand Canyon). Several months ago I bought new tires for the Trek 520 that I use for commuting daily. I went from the stock 35s to 25c Armadillos (difficult to change flats on, BTW, maybe the rim is a little too wide?). Should I buy some wider tires for the tour, or can I keep the 25s on? I plan on carrying a tent, bag, etc., but no cookset to save a little weight. This will be as light as I can, but enough gear to still be comfortable at night up in the mountains.