I started with Springer Bike Attachments so I could run 1 to 4 dogs on the side of almost any bike. Pedal powered biking with dogs means they don’t have to pull but can simply walk, trot, or run with the bike for exercise and adventure! With the dog’s on the side I had complete control of the dog’s as they are tight to the bike and if any temptations like other dogs, squirrels, or people for that matter came along the dogs aren’t able to chase as they are tethered close to the bike on the Springer. The dogs also can’t over power the Springer as it’s essentially a big spring so it absorbs all their force and won’t take the bike off balance or take the bike in any other direction. But the dog’s can if they choose can pull in the direction the bike is traveling for more exercise and especially good for natural pulling dogs like sled dogs.