I've done some background research and have come up with a confusing problem. My headset is old and it has problems staying tight. I figured the best way to resolve this issue would be to replace my headset. I noticed that Sheldon Brown had a cribsheet with Austrian headsets in it, but it doesn't look like mine. The Austrian headset looks like the one pictured in the BMX headset photo. My headset can fit a French stem (22.0mm) guaranteed, as I have tried an ISO one (22.2mm). The bottom bracket is English threaded. Is there anybody that has a similar bike that can shed some light on this? If it helps, I have an '82 AD Alpina, probably a mid-range bike, pictured in catalogs on the same page as the Pacifica.