It was a pain at first until I made my own 90 degree air chuck, the wheels come with a hidden valve stem that actually goes inside the wheel, so when you look all you see is a tiny flat disc that sits about 1/8" or so above the wheel, then to inflate it you had to screw a stem into it .
I had two problems with this, one..if I lost the screw in stems, im screwed, two...the stem was too long to fit in between my drum.
I ended up changing it over to a shortie stem so I could still have room to access the stem and still have clearance for my drum and caliper.