Just for awareness sake if any are searching forums etc in the future. Endurance trial title tests have to be done on a loose lead if you choose to bike the test for the 20k's, the springers and other bicycle attachments are not allowed for safeties sake for both the dog and rider. theory is you chuck the leash from hand if you are going to stack so dog remains safe.
I like the springers, had one briefly. Train train train no matter what if using one of the attachments, same as loose leash, tethered leash, free running. Bicycle awareness, and respect of the wheels is the #1 thing for safety.
If you find yourself going through hell; Don't stay. Just keep on going.