A Quick Pulley Comparison… They All Rock!

Written By: Lance Piatt

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Hey all, I wanted to give a quick run down of some niche comparisons.  Most pulley manufactures today make amazing gear.  When I say most, I mean those within the centric conformity of  standards, safety and accountability.  We’ll be looking at CMC, Rock Exotica, and Petzl … and then, only a niched down subset of pulleys.  This subset consists of the comparative nature of sideplates, sheaves and such.

Example… Rock Exotica supplies a myriad of pulley styles… The Machined Pulleys vs the Omni Block for example are “pulleys” and both have sheaves and sideplates, but a comparison is tough.  They aren’t made for the same purpose or user.  Otherwise, one or the other wouldn’t be needed and while we (the Rigging Lab Academy and Rescue Response Gear) have and continue to use these products… We aren’t making any recommendations because within this niche… They All Rock!

So in order to set this comparison up… I am looking at this type of grouping.

  1. Lightweight but strong
  2. Smaller in size but handles 80% or more of all applications
  3. High efficiency
CMC ProTech Pulley

OK… So let’s start with CMC ProTech. Ideal for mountain rescue, swift water, ski patrol, tower work or other technical uses, where equipment weight is a significant consideration, these lightweight, full-strength Prusik-minding pulleys feature extremely low-profile stainless steel hardware to reduce snagging on rocks, roots, and uneven surfaces. By machining the side plates, the thickness of the metal can be optimized to maximize the strength-to-weight ratio, a process that cannot be done with the traditional bent metal side plates. The unique axle assembly delivers a smooth side plate and impressive strength. The aluminum sheave is mounted on sealed ball bearings for high efficiency. Ideal for small block-and-tackle kits.

So this class of pulley is designed:

  • Primarily for 11mm
  • General Use NFAP
  • Super Strong
OPTION ITEM PRODUCT WEIGHT SHEAVE TREAD SIZE TYPE COLOR NFPA RATING 3 SIGMA MBS
Single 300501 3.3 OZ (94 G) 1 X 7/16 IN (25 X 11 MM) SINGLE SAND GENERAL USE 36 KN (8,093 LBF)
Double 300502 5.5 OZ (156 G) 1 X 7/16 IN (25 X 11 MM) DOUBLE SAND GENERAL USE 37 KN (8,318 LBF)

 

Rock Exotica Mini and Rescue Machined Pulley

The Machined Mini and Rescue Pulleys are designed and manufactured like no other pulley in the world. Starting as a block of solid T6 aluminum, the sideplates for the pulley are milled in such a way to leave material where it’s needed most for strength. And because the sideplate starts out of as a solid block, the axle for the pulley is left as an integrated part of the sideplate, further adding to its strength and overall rigidness.

The integrated axle also allows the pulley to use a custom manufactured threaded bolt which is countersunk into the sideplate, giving the pulley a unique snag-resistant profile. These one-of-a-kind features are the basis for the Machined Pulley’s impressive strength, slim profile and a quality of manufacture that is second to none.

    • Recessed axle screw sits flush to pulley side plates, creating slim, snag-free profile.
    • Machined—not stamped parts, create a stronger pulley, increasing its strength-to-weight ratio
    • Axle is integrated into side plates, adding additional strength and rigidity to the pulley.
    • Machined side plates allow for a more compact design while maintaining the same rope capacity of other pulleys.
    • Utilizes high-efficiency bearings

The Rescue Machined Pulley is…

  • Designed for 13mm rope
  • 36kN  MBS
  • 8kN WLL

The Rock Exotica Mini Machined Pulley is…

  • Designed for 11mm rope
  • Single 30 kN MBS/5kN WLL
  • Double 36 kN MBS/8kN WLL
Petzl Suite of Lightweight Technical Use Pulleys

Petzl generally has 3 classes of pulleys and it could be said that a 4th as well.  These “classes” of pulleys are super small, lightweight small, more generally sized pulleys and the fourth class would be the progress capture pulleys.  Petzl has a sub-class of this fourth one… the Petzl Petzl Pro and Pro Traxion. Both have a side plates that allow for rope connection while set on the carabiner (Pro) and the other is similar to the Pro but includes a progress capture device (Pro Traxion).

For this piece, we’ll simply look at the more technical lightweight small pulleys… The Petzl Mini and Petzl Gemini

The Petzl Mini is highly efficient and lightweight prusik pulley that is compact and offers a lightweight solution for setting up progress capture systems. Super efficient for the size and mixes well with an abundance of mechanical systems.

The Gemini is a highly efficient and lightweight double Prusik pulley that functions is a compact double pulley that sets up progress capture systems of high mechanical advantage.

The Petzl Mini Specs:

  • Rope compatibility: 7 to 11 mm
  • Sheave diameter: 25 mm
  • Ball bearings: yes
  • Efficiency: 91 %
  • Maximum working load: 2,5 kN x 2 = 5 kN
  • Weight: 80 g
  • Certification(s): CE EN 12278, NFPA 1983 Technical Use

The Petzl Gemini Specs:

  • Rope compatibility: 7 to 11 mm
  • Sheave diameter: 25 mm
  • Ball bearings: yes
  • Efficiency: 91 %
  • Maximum working load: 2 x 1,5 kN x 2 = 6 kN
  • Weight: 135 g
  • Certification(s): CE EN 12278, NFPA 1983 Technical Use

Obviously this list is really thin and while the comparisons are solid, if you’re anything like me… you’d like a more dramatic look into the pulleys in use.  Well, we have that planned very soon.  We are building an entire course on pulleys and the associated gear… Think “transitions”!!!!  See you soon.

Peace on your days.
Lance

 

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