David Dorn
Visitor
|
Product Test: Kiteboard Leashes - 2006/07/18 01:39
Product Test: Kiteboard Leashes
Review of Board leashes for kiteboarding,
Overview of the use of kite-board leashes.
Over the last ten years we have used and tested every kind of board leash available for kiteboarding purposes. Thousands of sessions and hundreds of leashes were used and pushed to breaking point in every situation imaginable. As the sport developed and the kites improved we found that; 1) there are no safe board leashes that can be used while kiteboarding. And 2) that board leashes are no longer necessary or advisable for kiteboarding. There are several types of leash that may be considered less dangerous than others, The function, and performance of all board leashes should be evaluated before being used in any kiteboarding situation.
HELMETS MANDATORY
Firstly, never use a kiteboard leash without a helmet. The leash creates a risk of board recoil, where the board can return to the rider with so much force it strikes the rider and may cause injury. Beware of any leash claiming to be “safe”. Some leashes may include “Safety features” that make them more safe, than others.
STANDARD LEASHES
Such as surfing leashes made from urethane cord, were often used as kiteboard leashes. However the forces in kiteboarding are more extreme than surfing, and the leashes often broke under the higher loads placed on them. The urethane’s elasticity was not suitable for many kiteboarding situations. The stretchiness caused a recoil effect that could endanger the rider. The boards would dig in, and stretch the leashes almost to breaking point, then the board if it surfaces would suddenly shoot to wards the rider, with extreme velocity. That could (and did) cause serious harm to many riders.
SUBMARINEING & TOMBSTONING
When leashes are used on kiteboards, the constant pull of the kite, on the board, can cause it to pearl, and dive under the water, fore long periods of time. The curved shape of the boards causes them to bite into the water and resist the kite’s pull. The boards would dive deep and sometimes drag along the reef sustaining considerable damage. Tombstoning is when the board stands on its tail and bobs in a vertical position. The pulling force on the leash and the hydrodynamic forces combine to create this common effect.
OFFSET ATTACHMENT POINT
One feature is the offset attachment point. It has been known for years that a centrally located leash attachment point increases the likelihood of the board recoiling back in a direct line with the force exerted on it, which is of course the resistance of the rider.
In surf leashes, and subsequent kiteboard leashes, the attachment points were offset so that the boards steered to the side, on a tangent to the force of the rider’s resistance.
The leashes attachment points may be determined by the person attaching the leash, and could be as arbitrary as the closest available screw hole. After much experimentation we determined that there is no “good” place to attach a leash on a kiteboard.
MINIMIZED RECOIL
To reduce the amount of recoil that a leash creates, riders have experimented with increasing the length. A short leash keeps the board too close to the rider. A longer leash can stretch further which absorbs more shock, but conversely may store more energy.
A longer leash was found to get caught around more obstacles, like shallow reef, rocks on the shoreline while launching. Another way manufacturers and designers of leashes tried to minimize recoil was to make the leash a static length of webbing, so that there was no spring/bungee effect. Wake boards had short static leashes that were attached to the center of the board. This caused the boards to dig in and create substantial drag. The riders wore the leashes connected to the knee cuff, to be above the binding boot, and to be (presumably) attached to a stronger leg joint.
RETRACTABLE LEASHES
Retractables were introduced to minimize recoil. They had a passive retraction spring that would wind the webbing up when there was no pressure on the board, this kept the leash neatly stowed until needed. This design would reduce the leash's tendency to get tangled, and reduced the amount of recoil. The problem with the retractable leashes that we have used, is that they have no safety , or quick release mechanism at the rider’s end.
This could cause an unsafe situation if the board got tangled with another rider, or submerged object, or a runaway kite. The retractable leash could (and often does) interfere with kite safety devices and causes the kite's safety depowering system to malfunction. Future designs must include a quick release at the rider’s end of the leash.
kite safe,
David Dorn
NOTE: many kiteboard manufacturers are advising against the use of board leashes.
Many kiteboarding schools, now teach new students without the use of board leashes, to improve safety.
Post edited by: admin, at: 2006/07/18 01:52
Post edited by: admin, at: 2006/07/18 02:11
|
Forum 
