Please select your home edition
Upffront 2020 Foredeck Club LEADERBOARD

Replacing your Karver Furler Quick Release Spring Kit

by Phil Anniss 25 Jul 09:00 BST
A structural furler © Karver

The Karver range of furling units has come a long way in the last 10-15 years, with each aspect of the design seeing incremental improvements. Captive pins with quick release mechanisms are almost universal on furling drums and swivels these days and they too have seen considerable development.

The quick release mechanisms rely on small springs which can get damaged and require replacement. This article will outline the evolution of the Karver captive pin systems and help you identify the correct replacement spring kit for your Karver furler.

In the really early days (pre 2011) the jaw pin was held in place by a simple U-Clip.

The first range of Karver furlers used a traditional U-clip

Version 1

To improve speed and ease of release, Karver introduced this torsion spring system, encased in a yellow cap, which has become a key element of their design aesthetic.

These spring kits were introduced from 2011 and were standard on all Karver furlers until early 2018 and are the most common type in circulation. The release mechanism relies on a small string attached to the spring which is the easiest way to tell you have a V1 Spring kit.

Version 2

The Springs in the V1 quick release mechanism are prone to damage. In an effort to improve the robustness of the design, Karver introduced their V2 kits in 2018. This time they turned the plastic cap itself into a button, which moves in a vertical plane on a compression spring,

Version 3

Hot on the heels of the V2 comes the V3 design which is being introduced gradually over the next 6-9 month. This is a natural evolution of the V2 and rather than the whole plastic cap moving, the cap is fixed and they have added a central stainless button. This should again provide further improves to durability and reliability

These spring kits are NOT INTERCHANGEABLE or upgradable - you must have the correct spring kit for your furler. Therefore, when ordering a replacement, it is essential that you order the correct version. In general, furling units bought between 2011-2017 and have a yellow string-pull will be V1. Furlers bought between 2018-2020 where the plastic end cap moves vertically are V2 and ongoing, new units will be V3.

A KF 0.9 Furler with the V2 spring system

Spring kits are also sized according to the unit - so when ordering you need to know the size of your furler and the spring kit version. E.g. KF2 Spring Kit V1.

Finally, a very important point to note is that the latest 3:1 Quick Release Sheaves ALWAYS have a spring kit one size down from the furler. So a KF2 3:1 QR Sheave takes a KF1 Spring kit.

If you are still unsure of which Karver system you have or to enquire about any replacement parts, please contact us at

For our full range of Karver furling units, see Karver friction sheave.

Related Articles

Sailboat Load Data
Optimising hardware and rigging design Find out just how far we still have to go in terms of understanding yacht mast and rigging loads, and why they are so important to the specification of sailing hardware and rigging systems. Posted on 30 Jul
Morf Block merges into Morfrac Systems speaks to the inventor, Nicolas Goldenberg At we're big fans of the Morf Block. The lightweight, 3D-printed block started as a DIY kit and has expanded into two ranges: high performance and high load. Posted on 8 Jul
The Low-Down on High-Load Dinghy Blocks
Allen, Harken, Ronstan and Morf compared At we love looking at the data and comparing products to gain insight. In this blog we look at the rapidly evolving world of high-load dinghy blocks and compare leading products on the market from Allen Brothers, Harken, Ronstan and Morf. Posted on 26 Jun
Spinlock's XTX available at
The latest innovation in rope holding Widely known as experts in rope holding, Spinlock is the go-to solution for many sailors when it comes to clutches and jammers. We've been looking forward to the launch of their new product, the XTX Clutch, ever since we got our first look at METS 2019. Posted on 19 Jun
Ubi Maior X3M Flight Blocks
The compact high flyer reviewed by Where does the Ubi Maior X3M Flight range sit relative to other blocks? Posted on 12 Jun
Allen Brothers overview from
Dedicated to manufacturing excellence We are pleased to introduce the Allen Brothers 20mm and 30mm Dynamic Block ranges on the website and decided to take the opportunity to have an in-depth look at this fascinating UK manufacturer of performance dinghy hardware. Posted on 5 Jun
nke - Finding Their True Course look at these high quality, precision navigation instruments nke is a specialist marine electronics manufacturer which has built a reputation, over 35 years, for high quality, precision navigation instruments for sailing yachts. Profiling companies like this is part of's raison d'être. Posted on 28 May
Ewincher - An alternative to electric winches?
A power-assisted winch handle requires no installation Electrification of winches can be a great benefit; reducing the strength and manpower needed on your boat and allowing many to sail short-handed or continue sailing longer in life. Is the Ewincher a viable, cost-effective alternative? Posted on 11 May
Extend your reach with Ronstan
The Battlestick is the self-professed 'next generation of sailing weaponry' Ronstan is an Australian born company who has developed hardware for both small and big boats since 1953. In this article we will look at their extensive range of tiller extensions which have become a brand in their own right: the Ronstan Battlestick. Posted on 30 Apr