it can accommodate a larger-diameter piston in comparison to a twin-tube shock. Its greater working area allows more damping control without having to scale-up the package with tubing of larger diameter, bigger components and more oil. The advantage: less weight and smaller packaging. And without the thermal barrier imposed by an outer tube, a high-quality mono-tube shock can more easily dissipate heat. Not surprisingly, the mono-tube gas shock is widely used on racecars competing in series ranging from the Winston Cup to the Baja 1000.
   The twin-tube low-pressure gas shock is the third type. Available from several companies, many of the cheaper variants are simply hydraulic designs with a plastic bag of low-pressure nitrogen placed above the oil in the pressure tube. Although allowing the manufacturer, at least technically, to claim it as gas-pressure shock, this Baggie design deteriorates quickly, marked by a short service life and limited resistance to aeration, hardly a surprise given the harsh conditions found inside a shock.
   Adjustable shocks have some enticing advantages. On a street-driven vehicle they allow compensation for normal wear, maintaining optimal