I know there are different types available, some with the nuts on the inside, some on the outer surface of the rim. I have a set of the former and they have two nuts, the second one serves as a jam nut for insurance(I always add some Locktite as well). As it turned out today, one of the stems had lost one of the nuts and a full on search proved futile. So, off I go to Ace Hdwre. but no luck there either. None of the SAE or metric threads would fit, thread was much too fine. So, here in the Orlando area we have a place I refer to as Toys R Us for men....Skycraft Surplus Sales. They have just about anything you can imagine for any project you can conceive, including thousands upon thousands of electrical parts, nuts, bolts, the inventory is endless. First I tried the SAE and metric stuff, no luck, the threads on the valve stem are too fine. Then it struck me, the nuts used to mount toggle switches, push buttons, etc., look the same and come in many different sizes. So I went looking in that aisle and found the right drawer out of a couple dozen, tried a half dozen for fit.....perfect. Grabbed six just in case, 2 for a nickel, cost a whopping 16 cents.
So, I said all that to say this; if you should happen to run into a similar situation and need an extremely fine thread nut, head to your local electrical supply. The lock nuts on a toggle switch or other device will fit, but the normal SAE or metric stuff won't. It saved me the trouble and expense of buying another valve stem just because one nut was missing. Now the only problem I'm still faced with is trying to break the bead on the rear tire of my 1200. Finally pulled the wheel and used a 10' 2x4 with a 6" chunk of wood for a fulcrum, the wheel laying on the driveway and the short end of the lever under the car. Tried it four times and two things happened: the bead didn't break but the 2x4 did. Tomorrow it's off to a local shop, really irritating.
