If you have an active dog you probably realize there is no way you are going to wear him out if you are on foot and your dog is on a leash. Biking with your dog is one of the best ways to really get your dog the exercise it needs. I think your dog would agree that running free while following your bike would be best. For many reasons, you may need to have your dog on some type of bike leash.
There are many types of bike leash on the market and all of them are some type of hard mount that fixes your dog in one spot in relation to the bike. The Tug & Tow is the only recoiling Bike-Leash. It allows your dog more freedom, and hence more comfort for the run, while still keeping you in control of your dog.