Andrew Price (Blender Guru): https://www.blenderguru.com/tutorials/rope

Rope: http://darkscarab.com/view/66

This one spins 3 circles around a Bezier:

http://www.reynantemartinez.com/how-to-model-a-rope-in-blender.html

Cylinder - Main Rope

• Modifier - Main Rope Armature
• Subsurf - Viewport=1, Render=2
• Parent is Main Rope Armature
• Has Vertex Groups, probably created by the Hook creation menu

Armature - Main Rope Armature

• Not parented
• Deform Envelope Distance: 0.208', Envelope Weight: 1.0
• In Pose Mode, select tip,
  • Bone Constraint:
    • Spline IK,
    • Target Main Rope Curve,
    • Influence 1
    • Fitting, Chain Length 40
    • Chain Scaling
      • Use Curve Radius (checked)

Curve - Main Rope Curve

• Not parented
• Modifier (Hooks, most connect to Empty Objects
  • Falloff
    • Type: Smooth
    • Radius 0

To prevent resizing of armature bones from sliding along curve, on the bone constraint, where we select Spline IK, under Chain Scaling, select Y Scale Mode=None, and XZ Scale Mode=None. (Use Curve Radius is checked, but this might not be important.)