Poly Chain GT Carbon is the superior belt to PowerGrip GT2, but they both have advantages over the other. Poly Chain belts are stronger and have a higher modulus which can contribute directly to energy efficiency and longer belt life. Also, narrower Poly Chain belts and smaller diameter sprockets can be used in place of larger PowerGrip drives.
PowerGrip belts are available in longer lengths and have different sprocket sizes that can achieve some speed ratios Poly Chain can’t. Also, if necessary, we have ACHE PowerGrip GT2 belts which have Z twist tensile cords that are made to track in only one direction. This feature is used for fan applications with large speed ratios and vertical shafts. The belts are designed to oppose gravity and stay in track on the large flangeless sprocket.
In some cases, Gates synchronous belts could be too heavy duty for ACHE applications. Drives that use motors smaller than 15 HP may not be rigid enough to handle our synchronous products. People often try to convert V-belts to synchronous belts on small motors to achieve energy savings, but there's not much efficiency that can be gained from low power motors. The advantage of switching to a synchronous belt in such a circumstance is the lack of maintenance and replacement. Most times, Gates has an equivalent notched or aramid/KevlarTM* V-belt that will produce similar results without the initial cost of replacing the belt and pulleys.
The bottom line is you should use Poly Chain unless you’re constrained to only use PowerGrip or if the motor is less than 15 HP.
*Kevlar is a registered trademark of E. I. du Pont de Nemours and Company