Limit Chain Tensioners Limit Chain Tensioners are extruded then CNC-machined from 7075 aluminum for optimal strength and low weight. A pair weighs 62 grams/2.2 ounces. Laser-etched graphics that include wheel position guides and two 10-millimeter/3/8-inch mounting holes ensure perfect adjustability on most frames. Available in anodized red, blue, gold and black with laser-etched graphics and stainless steel hardware.