Quote Originally Posted by Jon Wehrenberg View Post
Lee, You need to understand that POG members rotate the valve stems and add extensions so the big black sensor caps can be installed on the valve stems. It gives me the shakes to think about how some valve stems with extensions and caps are flexing while the tires are spinning but I don't know of another way those type sensors can be installed. The outer dual has the stem rotated 180 degrees so the cap which is quite large can be installed. Trying to install it while the stem points through the hole in the wheel is not practical

Your buses and mine likely have standard stems with no extensions and we just reach them with a long, straight chuck.

Jon

My answer was in response to the question as to why all the stems face the same way. From the center of the rim to the mounting surface. I spooned tires on and off when I was a apprentice and the stems always face the same way so that no matter where the flat is the wheel can be fitted once.

If I were to install external tire pressure monitors on the outside dual of my coach they would be mounted on stubby stems. In fact if interchangeability is not a concern short stems could be used on all outside duals. This would make checking pressure and airing much easier.