I purchased the original PRS-21 back in 2008, because I wanted a repair stand that didn't clamp the frame. Recently, where the bottom bracket makes contact with the frame, that part broke. "The Bottome Bracket Support." The reason it broke is because the part seems to be made of nylon. I purchased a replacement, one that is steel and fits the PRS-22. I was concerned the drilling on the part would not be compatible with my PRS-21. But everything lined up, and this replacement part is a massive improvement now for my stand, and I hope to continue using this stand for many years to come.