- It was a center track belt.
- It was about 3 years old.
- It did break at the scuff. Meant to say that in the original post.
- I always loosen the eccentric to install or remove the belt.
- My tandem has only one set of couplers and I travel with it in an Evoc case. The belt is velcro'ed to one of the rims on the side with the disc, and that side is always facing inward, toward the bike.
- I use the Gates app on my iPhone to set the tension according to their spec.
I am sure that the scuff ultimately caused the break. I wasn't really questioning the why here, just wanted to hear if anyone else had a similar experience. And maybe what other failure modes people have had with the Gates drive.
Thanks