For offroad driving it is quite common that you air down the tires to increase the contact area of the tire to the ground. Back on the road this makes for severe tire wear if you don’t get the tires up to the required pressure. The tires will heat up significantly at higher speeds and the side stability isn’t the best either.

For this reason an onboard compressor is a nice add-on to the Pinz. The compressor has to be able to deliver the required pressure and should be large enough to produce an airflow which allows you to fill up your tires in a reasonable timeframe. The typical small “inflators” will have a short lifetime if you air up 4 tires from 12-15PSI to 30PSI or more and it will take you forever to get there. A better solution are 24V heavy duty compressors as they are available as military surplus. These compressors usually can deliver far more pressure as they are rated for! One typical example, the compressor of the Hummer, is rated for 50PSI but can actually go beyond 125PSI. Some safety precautions are in order to make sure that nothing “unwanted” happens on or after the trail.....

This is a typical setup as it can be used for such an installation. The pressure switch can be one from a normal mains driven compressor. To increase the power handling capability both contacts can be conneted in parallel as there is no need to switch the ground connection too. Naturally the pipes and hoses as well as all the fittings and valves have to be capable to stand the max pressure in the system. The overpressure relief valve has to have a switch point which is well below the maximum rating of the pressure tank. Electrical wires have to be of sufficient gauge (see the wire calculator) and the switch and fuse have to be selected matching the compressor ratings.

Contributed by Juergen Schoepf

Some “installation places”: