+1 on that gauge. I bought one and it works great.

 

For my '08 FLHRC, I purchased the HD guage with the hose. For putting air into the rear tire I use a small, standard air chuck that is about 30° bent from straight, as I can't find a 90° chuck. I rotate the rear wheel so that the valve stem is at about the 8'oclock position, remove the left-side saddlebag, and come down the left side vertically, bending the chuck only enough to seat on the stem.

 

Make sure the valve is on the bottom, use a flexible air hose, and lay down and air the sucker up. If I can do it on an Ultra, you can too.