A familiar sight at any trail head these days is to see wheelers airing down their tires in preparation for the up coming run. They air down their tires to increase the contact patch of the tire with the terrain thus increasing traction. Of course when the trial ride is over and it is time to drive on the street again it is important to air up the tires before hitting the pavement at normal highway speeds. Many companies have built electric and engine driven air compressor systems to help with this task as well as in some cases to run air tools for doing trail repairs. These systems however are anchored to the vehicle and you are limited by how ever long the hose is as to what the range is on using the system on another vehicle. For the last several years companies have been converting CO2 tanks for use in airing up tires and running air tools. Ultimate Air is one of these companies and they sent us this excellent example of just such a system so we could try it out and give our verdict.