i remember reading somewhere (that part i don't remember

) that the new angled valve stems were fitted especially for the new wheels and were not retrofittable to older wheels.
could be bs, but, maybe not.....
personally, i just use an extension hose that i made out of an old bicycle pump, the kind with the clamp fitting. i cut the hose off, took an old valve stem that i got from the tire store, cut off a bunch of the rubber so that just the brass tube core was showing, and shoved that up the cutoff end. covered it with some heat shrink, and then used a hose clamp to keep it secure.
now to air up my tires, all i have to do is to clamp the one end on the wheel, then apply the air chuck to the free end and air up to my hearts content. use it to check the pressure as well. and with the clamp, you lose very little air during applying/removal of the clamp end.
hd makes one as well, but mine was cheaper (free) and is a little longer.
http://www.harley-davidson.com/store/valve-stem-extension