I have a 8 month BC, Auzzie. She is just great. We walk her every day in the hills and let her go off leash 100% of the time. One trick I taught her from the start was to understand "GIT". It means get out of my way on the trail. She learned real quick to get going if I said GIT.
. I used that word while mountain biking and she stays out of my way. I have taken her about 8 times and she has been perfect. When going downhill i just yell out GIT, GIT. She gets it.