Anyone do it? We have an awesome park with trails and I've been thinking about taking up bike riding with Gunner. I'm honestly afraid and don't know how to start. He's STRONG and one good pull could cause a bad wreck. We go on walks, but I have some bad joints from a horse accident, and riding a bike would be better...plus we could go farther and get all of his energy out. Any ideas on how to start or how to train him to jog without pulling me over?