I recently came across this thread, and -- FWIW -- would like to offer a suggestion. I recently started using an extension hose, to both check and add air to the rear tire on my XCT. The particular extension I have is one offered by Stop & Go: http://www.stopngo.com/10-inch-mini-...ose-extension/
This particular extension is:
- Long enough, and not too long.
- Most importantly, it is both very easy to screw on and unscrew from the valve stem -- nice, big, knurled, female end -- and there is a fine depth of connection -- that is, it doesn't spew air from the tire, while connecting or disconnecting it.
I find this MUCH easier to connect to the rear valve, what with the disc and the belt and the bike leaned over, than connecting either a tire gauge or either a screw-on or clip-on chuck. Once you easily screw this on the valve stem, the other end is nicely out in the open, and you can use whatever you like to check or add air.
Scoff if you like, but I find this makes dealing with the rear tire almost a pleasure, and it's now a permanent saddlebag addition for overnight trips (along with a tire gauge, shock pump, etc.). I'm guessing that it work well on the spoked XR tires, too.