We are the proud new owners of an adult (approx. 6 - 7 year old) labradoodle that we adopted a couple weeks ago from an animal shelter. As first time dog owners, we've been reading materials about how to make this transition successful, and stumbled across Cesar Milan. We've been following his formula to successful dog ownership, exercise - rules / limitations - and affection. Our dog is high energy, and during our first week even though he was walking 4 miles a day and running two miles on top of that, he wasn't really challenged enough. I tried taking him for a bike ride just holding on to the leash, which was very exhilarating but highly dangerous for both of us. That night I started digging into reviews of bike leashes, and settled on this one.There are plenty of other reviews about the specs, so I'll focus on our experience. I have a Specialized 29er with disc breaks, and while it was a little challenging to figure out where to attach it to the frame, it wasn't impossible. It does not fit over both the chain stay and the seat stay, but I was able to attach it to the chain stay and it is very secure. It does not interfere with the disc breaks. When not in use, it slips up nicely and clips under my seat.It was very easy to set it up and apply it right out of the package. I attached it right to our dog's 1" collar, and we were ready to go. I was initially a little concerned about it pulling on his neck, but as I've been observing him as he runs, it isn't pulling on his neck at all. It's merely a guide as he runs along. If this becomes a concern, I will purchase a harness as others have suggested. I had initially been having him heel on the right side, so it took a slight adjustment for him to be on the left. He did have a tendency to chew on it when we were initially getting set up, so we worked on that immediately to prevent him from damaging the leash.He weighs about 50lbs. Ever since we adopted him we've been teaching him to be focused when we're on walks, and biking hasn't been any different. Any distractions that have come up have been very easy to correct. When I was stopped and another dog came along, he was able to pull the bike around to go sniff the other dog, so that might be a concern with a dog that has a tendency to randomly lunge.I did not make a separate trip into our vet for permission to use it, as I had just had him into the vet last week and was give a clean bill of health. We have been starting out gradually, only allowing him to go a couple miles in the beginning. I hold him back in the beginning for a warm up, then let him run for a while, following it up with a walk on the leash for a cool down. So far, our longest ride has been about 4 miles. I have been keeping a close eye on his pads for wear and hot spots. He still seems to have plenty of energy, but getting better exercise than we could provide by only walking and running at our pace seems to have helped tremendously with his excess energy. Getting exercise at his level has allowed him to be much calmer around the house, and has cured a great deal of his restlessness.Being a newbie dog owner still, I have weeks of experience instead of years, but a key seems to be that you keep working with your dog in all kinds of different situations. Starting in a less trafficked area with few distractions seems like a wise choice to me, and then gradually work in more obstacles and distractions. Having a consistent working relationship with your dog seems key too.All that being said, it's going to be a whole lot nicer to get out in the rainy, 50 degree weather today and go for a 25 minute bike ride instead of a 45 minute walk, knowing that my dog is still getting the exercise he needs. If we have issues with the structure and longevity of the device in the future or further safety concerns, I will update.