Any bend in a mechanical advantage system should be how much larger than the width of the rope?

• A. 2 times
• B. 3 times
• C. 4 times
• D. 5 times

Answer: (C)

Bends in a rope system create stress concentration, so you want the rope to flex gradually rather than kink or pinch. Keeping the bend radius at least four times the rope width ensures load is shared across many fibers and reduces the risk of fiber damage, kinking, or weakening under load. When bends are tighter than this, the outer fibers are stretched more while inner fibers are compressed, which can shorten rope life and even lead to failure under dynamic or repeated loading. Using generous pulleys, sheaves, or edge protection helps maintain that four-to-one radius and protect the rope. So, the best practice is to keep bends at four times the rope width.