I've been using the Springer bike attachment for 5 years. It can be a safer alternative to holding onto the leash while bike riding. But you must train your dog from the ground up.
Most important... Your dog needs to learn the "leave it" command for distractions. The words used by mushers are "on by", meaning move on by the distraction.
Next you can teach directional commands during leash walks.
-I use "over" for right.
-"This way" for left.
- "Easy" for slow down.
Mushers use Gee, Haw, and Hup, but you can use whatever comes naturally as long as you're consistent.
Start slow on the bike using the side clip of a Walk Easy Harness for the most control. The harness Springer provides doesn't control the dog well enough.
I progressed to a Y-back harness so my dog has freedom to full out run, but I wouldn't recommend this if your dog remains unruly on the trail because it is designed for pulling. If your dog doesn't respect the bike and the "leave it" command for critters, a pull toward or away from the bike will result in injury.
I'll eventually do a full tutorial because so many people ask me about where to get the Springer and how to use it. But I want them to use it safely.
The Springer is not for every dog and you must know your dog's limits for exercise, heat tolerance, and water needs. It's also your responsibility to keep the burden off your dog and follow their lead for pacing. Understand this is physical for you too, especially up hills. A lone dog should not be pulling you constantly.
Note about the opening photo: We use a bike trailer for the bird to come along. It's an extra pain but... let's call it keeping the pets happy:)