We used to bike with our ACD mix when she was younger and needed that level of exercise. She really enjoyed it, getting to tour the neighborhood at high speed! I also taught my brother's lab mix to run beside my bike when I was babysitting him for a couple of weeks. Both dogs picked it up very easily. We don't use any special equipment, just ride one handed, so we can control the leash and keep dog and leash away from the bike with an outstretched arm. I understand that there are devices which could make it less likely for the dog to dump your bike.
The dogs were taught to run on the right side of the bike, so they would be away from traffic (not that there is much in our neighborhood) and so, if they did pull us over going after something, we'd fall onto the shoulder instead of toward the middle of the road. I only wiped out once with ACD mix. Until they got good at following verbal commands for which way to turn and we had practiced left turns while walking the bike, I made only right hand turns while sitting on the bike...lefts are tricky, as the dog has to come around on the outside of the turn. Oh, we also taught a "come around" command, so that if the dog did somehow get on the wrong side of the bicycle, we could tell them to come around in back of the bike to the right side.
I rode dogs with my seat a bit low, so that I could get both feet on the ground quickly, for stability, if I needed to. I also prefer a cruiser style bike, which is heavy, doesn't require messing with gears and has the big wide handlebars that are easier to control with a single hand.
I would not bike with a dog until it is truly full grown, running fast on pavement is hard on their joints. Also, watch for signs of their tiring, I know with our ACD mix, she is so driven that she will not stop what she is doing, no matter how tired, sore or anything else she might be, full speed charging ahead at all times, so I had to be the one to rein her in and call it quits before she got to tired or overheated.
