The beauty of biking the CD is you don’t have to carry much food or other supplies since towns come every 2 or 3 days. You will probly need a single wheel trailer, though the inexpensive one at Nashbar gets mixed reviews for breakage tendencies. I saw some CDB’ers carrying ridiculous amounts of food & supplies… it’s better to carry extra tube-patches, pump, & tubes, spokes & emergency rope-spokes, tools, tire patches, spare bolts & screws & spare anything else small that might shake loose & ruin your trip necessitating the use of duct tape & a coat hanger! I don’t recommend kevlar tire liners or slime-tubes (the liners crimp & pop your tube… the slime filled tube can’t be repaired in a pinch, though I always prefer to pop a new tube in to keep moving & repair the broken tube later in camp). As a bike messenger for 2 decades, I saw & experienced it all including broken chain (carry emergency links& chain breaker) skipping chain (lubricate &/or avoid using the skippy sprocket) broken cables (have all new brake & derailleur cables b4 u start & of course carry extras & a good cutter)…also, if the whole group uses similar bikes, spares can be shared. You can’t go wrong starting out with a fairly new bike, but ride around on ur local trails for a month… most bike shops give a free checkup/tuneup/wheel trueing at that point ! Carry extra spokes becuz very often the next bike shop doesn’t have them in your size ! Hope you are able to comfify a trailer for your dog.
inchworm plumber