Can you sew the seam on treadmill belt?

Yes you can if it was glued from my experience. My belt came apart at the seam where the glue had held it together. I think I was fortunate because it was a clean separation and had about 3 inches of overlap to work with. I cleaned the two surfaces with soap and water that would be reglued and used Super Weatherstrip Adhesive by Permatex found at the auto parts store. It was about $7 which is far better than the $90 - $170 I found online to replace. After regluing and letting it set for 24 hours I reassembled and now it works as good as new even at 15* incline at 10 mph. Good luck everyone.