JERK-EASE Patented Shock Absorber Bungee Dog Leash Attachment, Large (Up to 110 Pounds), Black

Has anyone tried this with a WalkyDog Bike attachment?

How can I be pro-actively working with the bungee effect of this extension?

90lb puppy pulls at the beginning of the walk. Need something with give to help pull her back. She doesn't chase anything. What's the best size?

sometimes dog reach around and bit the leash, if i use this, can the dog hurt her teeth bitting the metal clasp?