I have seen in other posts on this site where people have suggested "add ons" for tire air valves, in this case a 45 degree neck to make access to the air valve easier. DO NOT INSTALL ANY DEVICE ON YOUR AIR VALVES!!!!!!
The extra weight on top of the valve will pull the valve flat against the wheel when centrifugal force develops as speed increases!!!!! I have seen "illuminating" air valve caps tear off air valve stems at their base because of this!!!!!!!! Do not install anything on your air valve stems! Ideally, a billet aluminum air cap with an oring seal will be best at maintaining your tire pressure if the air valve itself depresses due to centrifugal force at extreme speeds. If necessary, angled metal air valve stems are available, they fasten into the wheel with nuts. This thread should be posted where everyone will see it, not just in the "tech" section.