I installed A S-3 on my group frame. I did no major prep and everything went together very smoothly. I've been riding it now for the last 2 and 1/2 weeks and have absolutely no issues with BB or headset. The bearings on the headset are very smooth. It did take a lot of effort to press the cups in,I did it with a homemade bearing press tool but they went in very straight and flush to the headtube. for the BB I used a plumbers pipe brush to clear the powdercoat overspray from the threads and used some synthetic grease on the BB threads it went in with no effort at all. I'm getting ready to remove the boat anchor I got a cheap carbon fork off EBay so I 'll look at the bearings on the headset then. The way they perform now I don't expect to see any problems.