Monster Craftsman Chain TensionerMonster Craftsman Chain Tensioner When building a custom motorcycle, chain final drive is often the most flexible power transmission method, but sometimes getting a straight run or avoiding chain slap isn't easy. Monster Craftsman eases moving power to the back wheel with their comprehensive line of chain tensioners. Ready to run tensioners (clamp on and bolt on) are finished in black powder coat Weld in tensioners are raw mild steel for easy welding