Full definition
Multiple V-belts permanently joined by a common fabric top cover, forming a single unit that prevents individual belt rollover, turnover, and jumping out of grooves. Designated by number of ribs plus profile (e.g., 3/SPA, 4/B). Essential for drives with severe shock loads, pulsating torque (crushers, compressors, presses), vertical shaft orientations, or long center distances where individual belts would whip. The tie band distributes load more evenly across all ribs. Per ISO 5290. Brands: Optibelt KB, Gates PowerBand, Continental CONTI-V MULTIRIB. Slightly lower efficiency (~1-2%) than matched individual sets due to added material.