[RottsNScotts]

I had a friend use the Springer with her Rottie; I TOLD her it was not a good idea but I guess I don't know what I am talking about. She went to great lengths to tell me how, if the dog pulls hard, it has an automatic release...

Yeah, well, her dog saw something he wanted and pulled the bike right out from under her, injuring her rather badly. (I promise, I did NOT tell her "I told you so"!)

I think a Springer, with a Rottie, is an accident looking for a place to happen. I have had the best results with dog on a pinch collar on a 6' leash as Mavides and Carol described.

I don't start my biking until dog is over 18 months...but they are doing plenty of physical stuff before then!

And I actually prefer to roadwork them in a cart rather than just the bike; the load builds their butts and they more correctly use their rears for power, transmitting the power through their topline which strengthens that as well.