Pulley system efficiency tests with Petzl’s Maestro, I’d S, Pro Traxion and RollClip

Written By: Lance Piatt

There can be a big difference between the theoretical efficiency of a pulley system and its actual efficiency. Here are test results from the Petzl lab.

1. Efficiency depending on the device used at the head of the system.

The force required to raise a 100 kg mass was tested under several configurations with different devices at the head of the system and with ropes of various diameters

  • MAESTRO S and L are built with the same pulley so their efficiency is the same.
  • Ropes tested according to diameters: 7 mm cord, PUSH 9 mm, AXIS 11 mm, VECTOR 12.5 mm.
  • The results are given for information only, as they depend on numerous variables that are difficult to reproduce in each test (position of haul system elements, rope diameter, hauling speed, hauling smoothness, the haul load…).
Simple Directional (1:1)
Simple Directional (2:1)
Haul System (3:1)
Haul System (4:1)
Haul System (5:1)
2. 3:1 Haul system efficiency depending on the redirect point used.


Gear Used In This Study


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