Two things:

First. Seems in this area, where most mountain bike trails are in state parks, the subject of mtb'ing with dogs can be a heated one. I believe Michigan state parks require dogs be on a 6' leash, so some riders get bent out of shape if a dog is not on a leash, and others simply don't like dogs being on the trail. I presume mountain biking with a dog on a leash is pretty difficult and dangerous, but must say myself I have never tried. What do you think? Dogs, no dogs, or dogs only on leashes?

Second. I have a dog - Golden Retriever/Australian Shepherd mix. She has a good amount of energy, and I would love to have her run along side me on the trail without a leash (as long as BF is cool with that idea :-). From those who have experience, how did you train your dog to run along side you as you bike? Was it difficult? When did you know it was the right time to take off the leash?