I'm not entirely convinced that converting to 1 inch threadless is actually an upgrade. Not that there is anything wrong with threadless (it is slightly superior to threaded, but just a little.) There are plenty of parts available for both 1 inch threaded, and 1 1/8th threadless. However, there isn't much out there for 1 inch threadless, or 1 1/8th threaded. If you have one of those, I'd just ditch it, as parts availability is scarce.