Please select your home edition
upffront 2018 Cousin Constrictors 20% Off 728x90

How to change the cover on a Cousin Constrictor

by Aleix Escorsell 30 Oct 09:00 GMT
Cousin Trestec Constrictor - A Textile Rope Clutch © Berschi

Created as a lightweight alternative to traditional metal clutches, the Cousin Constrictor© is a great bit of kit for reliably holding rope under load with great longevity when properly maintained.

Rope innovators, Cousin are at the cutting edge of marine rope and textile technology and have been able to revolutionise the French racing scene with great products such as the Cousin Constrictor©.

Cousin claim that their Constrictor is three times lighter than metal alternatives and twice as powerful. Coupled with the fact that the Cousin Constrictor© does not damage the line in any way makes it a great alternative to traditional rope clutches for a variety of boats and yachts.

This blog will help owners of the Constrictor, and those looking to purchase this versatile textile rope clutch, learn more on how to properly maintain and increase the lifespan of the Constrictor. With a step by step guide, and examples provided by Cousin, you will be able to confidently look after your Constrictor and change the cover if needed.

Looking after your Cousin Constrictor©

The sleeve is made of a high tenacity black technora, which is extremely sun and heat resistant, and the casing is made of an anodized aerospace-grade aluminium housing.

All of this makes the Constrictor a reliable and extremely durable clutch. However, as with any textile product, usage does wear on the sleeve over time. Cousin recommends a few tips and tricks to improve the lifespan of your Constrictor:

  • Avoid over-loading where possible. The Constrictor can hold as much as the rope can, and grip actually increases with load! That said, high load over time will eventually wear the Constrictor and can lead to damage.
  • Regularly wash the Constrictor© with fresh water. Harmful compounds such as sand, sea water, sharp equipment and chemicals can do damage to the Constrictor. Washing with fresh water will help improve longevity.
  • In winter, uninstall the Constrictor or use a cover when not in use.
  • Avoid cleaning the Constrictor with high pressure cleaners that may introduce abrasive elements into the fibres.

Even with excellent maintenance, wear and tear may lead you to require a replacement sock, but how do you know when to change?

Here are a few key things to look out for:

  • Is there any obvious damage such as cuts or tearing?
  • If you can see the rope beneath the sock, it may be time to change your cover.
  • Is the cover fraying or fluffing up?
  • If the pattern on the cover is no longer consistent or you can see strands that have detached from the main sock, this could be a sign that your cover needs to be replaced.

Particular attention should be paid to the junction between the braided sock and the cone fitting. This is where the sock exits the aluminium fitting and the most likely point of significant damage.

If you do see damage to the cover, it's important to assess the damage and change it if necessary. Below is a step by step guide on how to change the cover.

Changing the cover of your Cousin Constrictor

Step 1 - Remove the Cousin Constrictor© from your boat

Changing the cover while the Constrictor is attached to the boat may cause damage to the Constrictor and the boat. Therefore, we recommend removing it before you begin the process.

Step 2 - Insert the metal punch (see note below on this custom tool) into the same hole that the cover comes out of, pushing the cover aside as you do so.

Step 3 - Bash the top of the punch with a hammer to release the titanium ring. It should come out of the bottom.

Step 4 - Remove the titanium ring and the cover from the housing and set them aside.

Step 5 - Insert the new cover into the housing and pull it through to the other side.

Step 6 - Carefully splay apart the fibres to allow the titanium ring to fit comfortably inside the end of the cover, then insert the titanium ring into the end of the cover, thinner end first.

It's important to ensure that the fibres are evenly spread around the titanium ring to ensure that the load is spread equally throughout the cover.

Step 7 - Ensuring that the ring stays encased in the cover, Pull the cover back through the housing and push the ring in to the hole. N.B. You should be able to see the cover all the way around the ring.

Step 8 - Using the punch and a hammer, punch the ring in to the housing. It should now be jammed in and unable to move and you should still be able to see the cover all the way around the edge of the ring. Pull on the end of the cover to ensure it is secure.

Ensure that you test your Constrictor with a light load before you sail.

With this guide you should be able to get the most out of your Cousin Constrictor©. Don't forget to regularly check your Constrictor for cuts and tears, regularly wash it with fresh water and avoid overloading it.


In order to change the cover yourself, you will need a punch (pictured below), specifically designed for this operation. The tool needs to be two thicknesses, the thin end needs to be able to fit inside the aluminium ring and the thick end needs to have the same diameter as the OD of the titanium ring.

While Cousin do not currently sell this tool, we recommend that you contact them regardless, as they are considering releasing them as a product in the future. If not, any decent metal shop would be able to craft the correct tool and can supply the dimensions.

It's important to stress that this tool is critical because it ensures that the aluminium housing is not damaged, and the structural integrity of the clutch is not compromised during the sock replacement process.

If you do not feel confident in doing it yourself, take your Constrictor to a local rigger for assistance.

If you have any questions about the specifications of the Cousin Constrictor©, or to buy a new cover, visit or alternatively use the contact form.

Related Articles

Ino-ending - The end of the line?
Simplicity is key with these blocks When it comes to the Ino-block range, the manufacturer firmly believes that simplicity is key, and Upffront tends to agree with them. Posted on 13 Nov
A Halyard Swivel, Top Swivel or just a Swivel? explain the options available There are many types of swivels used on board boats, several of which are mounted on halyards, however, the term "Halyard Swivel" is reserved for one specific application. Posted on 7 Nov
The Facnor Flatfurl Structural Furler
Keeps the foot of the jib/genoa closer to the deck Facnor Furling Systems are a French manufacturer with over 30 years dedicated to all forms of onboard furling systems for ocean racers and cruising sailors alike. Posted on 24 Oct
What makes Superswift rope so super?
Take a close look at this versatile offering from Gottifredi Maffioli Superswift, from leading rope makers Gottifredi Maffioli, is a favourite among performance dinghy sailors and big boat sailors alike. When you take a closer look at the features of this versatile rope, it's not difficult to see why... Posted on 16 Oct
One Design PROtect Tapes
A set of cut pieces tailored to your class PROtect Tapes are a broad range of high-quality protection tapes for dinghies, racing, cruising and super yachts. PROtect Tapes provides a pro-active solution to chafe and wear prevention. It enhances performance and ultimately promotes safer sailing. Posted on 10 Oct
Practical tips on cruising halyard locks
Bouncing to avoid damage Halyard locks are almost universally accepted in racing circles and are becoming increasingly popular with long distance cruisers, as they recognise the significant benefits. Posted on 2 Oct
Baby Karver Furler KF 0.9
The smallest furler manufactured by Karver, for boats under 30ft Launched this year, this is the smallest furler manufactured by Karver. With a Safe Working Load (SWL) of 900kg, it is suitable for small cruisers and sportsboats up to a maximum of 30 ft. Posted on 26 Sep
Karver KJ Jammer
Releasable under (low) load combined with the reliability of a high load jammer French hardware manufacturer, Karver has been active in the French offshore sailing scene (IMOCA and offshore multihull) since its inception in 2004. Their reputation is based on developing a range of innovative products. Posted on 18 Sep
What is a top down adapter?
A tack swivel is a popular evolution of the top-down furling system The top-down adapter, also known as a tack swivel, is an increasingly popular evolution of the top-down furling system. This technique provides cruisers and racers alike, simplicity, safety and speed for the handling of loose luff sails. Posted on 12 Sep