Belt grinds on the frame (ST3 Pinion)

On belt-driven models, the top of the belt may rub against the bottom of the right-hand chain stay.

These are apparently assembly errors ex works.

The solution is simple: (Source)

1. Remove the belt from the front pulley
2. Use a 4 mm Allen key, split pin or spoke to block the tensioning pulley swivel joint so that it does not scratch the frame
3. Use a T25 (Torx) wrench to remove the tension pulley and refit it two holes further in an anti-clockwise direction
4. Replace the belt, unlock the swivel joint and you're done!

Wrong: If the tensioning pulley is located directly on the front pulley, the frame is spared, but the belt will certainly not age.

Correct: This is how it should look.