Ratchet pulleys and speed systems

The ratchet system enables the pilot to temporarily prevent the speed-bar from returning to its default neutral position, and also limits the “push” during long, accelerated transitions. The principal is simple: If load is applied to the line in one direction the pulley turns freely but if it is applied in the opposite direction the pulley locks, therefore less effort is required to hold it in place. The effort needed to keep the speed bar pushed can be reduced by to a 90%, which means that applying a force of 2 kg on the speed bar will keep on 20 kg of pressure, and the rest of the effort is transmited to the anchor point of the pulley itself. In the event of a collapse on full speed bar, the pilots only needs to release the pressure which will instantly release the mechanism and therefore the brake pressure.

There are two well-known brands of pulley used on paragliding harnesses, Ronstan and Harken. Both are made from toughened materials (resin, aluminium, stainless steel), and have been used for several years by manufacturers such as Kortel Design and Sup’Air, Swing on some of their standard harnesses.

Block pulleys of Harken company specializing in nautical fittings

The ratchet pulley system can be fitted on to any existing harness, and two or three-step speed bars can be found ready-made online. You can also fit the system yourself, but this point it is importance to stress the use of the correct materials.

The rope used by the majority, is a standard nautical or dingy rope, 5-6mm in diameter. The importance is that the rope needs to create the correct amount of friction on the pulley but can also be threaded through a Brummel hook in order to connect with your brakes. You also need to check that the small pulley stitched onto your risers, which hold the brake line Brummel hooks can withstand the pressure from the new ratchet pulley system.

For the system to be effective, an angle of at least 90° between the riser and the speed bar is required. The larger the angle, the more surface contact there will be between the sheave and the line, therefore improving the holding power. The ideal angle is about 180° however a tailored installation with an additionnal smaller pulley may be needed on the inner side of your harness in order to achieve this.

A new ratchet pulley by harken has recently been released, the T2 Rachamatic 40 mn block pulley (download very long!!!) , which is smaller and lighter. Pulleys can be purchased online although the cost varies depending on whether you are purchasing from your dealer or directly from the internet.

Harken T2 Ratchamatic Block Pulleys: the old 57C size and the new size 40

ROSTAN block pulley

The KORTEL DESIGN pack

KORTEL DESIGN pack with HARKEN pulley – read more on the website KORTEL DESIGN

The SUP’AIR barefoot with Harken block pulley

The competition barefoot with HARKEN block pulley 40 mm! – read more on the website SUP’AIR

Mario Arqué at Perfils www.perfils.info (email : mario@perfils.info) sells pairs of pulleys and will be happy to help with advice on how to get the best out of them and how to attach them to your harness.