Okay, our tensioner bearings are ID 20mm, OD 37MM, width 15mm. It turns out to be no big deal on McMaster-Carr to find a sealed earing --- even stainless --- that is 37mm OD and 20mm ID and 12mm wide --- 3mm narrower than our bearing. What's 3mm between friends? Can't we make that up with a washer? VO