A sandrail is a type of machine that is used to race and play on sand dunes and sandy areas. The most common type of sandrail is a rear-engine, air-cooled vehicle powered by a Volkswagen engine. Mistakenly referred to as a dune buggy, the sandrail is a completely different type of vehicle using tube chassis construction and is rarely street legal. It is not uncommon for a sandrail to be operated with no body panels or windshield. The open tube-type chassis not only provides light weight for the vehicle, but it also allows the sand to fall and pass easily through the vehicle, thereby eliminating the messy clean-up the vehicle would otherwise require.
The Volkswagen air-cooled engine has been the power plant of choice for the sandrail due to the elimination of a radiator and cooling system while retaining cool engine temperatures even after extended use. The rear mounting position of this engine not only provides a well-balanced vehicle, it eliminates engine heat from blowing back on the passengers of the vehicle. With nothing in front of the passenger compartment except the chassis and front tires, there is little threat of injury due to leaking engine fluids or clutch explosions.
The sandrail also benefits from the transaxle assembly of the Volkswagen. The transmission is mounted in the rear of the vehicle, just ahead of the engine. This assembly also offers independent rear suspension, which makes the vehicle much more stable on uneven terrain. Many sandrail owners choose to fashion the rear brakes independently of each other to allow for tighter turns. The typical machine will have no front brakes since the relative lightweight aspect of the vehicle is easily stopped by the rear brakes alone.
It is common for a vehicle of this nature to have no gauges or warning lights other than an oil pressure indicator on board. This is due to the lack of cooling system and a very basic charging system. Most Volkswagen-powered vehicles use a six-volt electrical system and many run a magneto ignition, which requires no electricity to run. Also, very few sandrails are equipped with lights of any type. With this vehicle, once the engine is started, there is no further need to monitor engine function.
A sandrail is routinely fitted with very wide paddle grip tires in the rear to provide flotation on the soft sand as well as good traction. The front tires are often very narrow and have no tread. Smooth tires in front prevent sand from being thrown in the passengers' eyes while the vehicle is in motion.