It is now common practice when four-wheeling to adjust the air pressure in your tires to meet specific terrain conditions. The job that used to be done by a core tool (valve-stem remover) or maybe even a sharp stick can now be done by a very cool product, the Rimrock RAD (Rapid Air Deflator).
The Rimrock RAD has been around for a few years but was known (or unknown!) as the Klune-V RAD. Rimrock Mountain Supply has purchased the patent rights and is now making sure all of you on the trails, dunes, mud, and snow are aware of this very easy-to-use product.
The main hindrance to letting the air out of your tires is the valve stem. The hole is so small that airing down can be a very slow process. The Rimrock RAD is a stainless steel valve-stem replacement that allows air to be released much faster. Although you can use it to replace most standard valve stems, we recommend that you drill a second hole in your wheel to really take advantage of the RAD.
The secret behind the RAD is the 12 holes that surround the valve core. A knurled nut seals the holes when the nut is tightened. When the nut is loose, the air comes out almost as fast as with a switchblade to a sidewall. What we do before we hit the trail is attach an air gauge (low-pressure dial-type) to the stock valve stem and then loosen the knurled nut. You can then watch the air pressure fall and close the nut when you get the air pressure where you want it. This is very quick and allows you to make quick changes as you change elevation or if the tire pressures change as the day gets warmer. Frequently, our wheeling takes us high into the mountains, and 6 psi in camp can easily turn into 12 psi by the time we climb to the top of the mountain.
We did some testing to see just how fast the RAD worked and were very surprised. Not only was it fast, it was easy. Using both valve stems allowed us to attach a gauge on the stock valve stem, watch the air pressure fall, and close the RAD at the proper pressure.