This creates a further disconnect between skier and ski relative to a conventional alpine binding. On the workbench, you can twist the heel of the boot with the ski held flat and see the boot heel and pins moving relative to one another. To finish the mountain bike analogy: a traditional tech binding effectively functions like a fully rigid mountain bike with a flat rear tire squirming all over the place. Conversely, an alpine binding functions like a finely tuned, full-suspension trail slayer: smooth, controlled motion on both ends.
Excellent article — returning from the side country, I took a nasty inbounds fall at mach speed on hard pack last winter in my Dynafit bindings. Late answer and maybe known facts already?! Learned after a season on Dynafits that one should always wiggle and slam the ski down a couple of times after attaching the toe, BEFORE attaching the heel, to make sure the pins are well in and no snow or ice is in the way. Foe me this has made a great difference and the nasty fake releases on high speed icy groomers are a thing of the past.
Excellent article that helps to clear up some long held misconceptions about bindings. Question for you though, at what level in the DIN range do you think a heavier spring binding becomes necessary, assuming the binding is reasonably well designed w decent elastic travel?
For example at a DIN of 10 is a binding such as a Marker Baron acceptable or would you think it necessary to upgrade to the Duke.
Ignoring any structural differences such as metal vs plastic, etc. DIN means is that it takes the same amount of force to release. The article implies that tech bindings do not offer the same level of safety as a standard alpine binding, but it seems to assume that tech bindings also will be run as a higher release value. What do you think of the relative safety of both systems if they are adjusted at similar and conservative release values?
Will the safety of the tech system be relatively close to an alpine binding and primarily compromise ski retention and control? Does this apply to both alpine and tech bindings? Several of the new systems like the G3 Ion are starting to offer systems similar to forward pressure but the main advantages highlighted by G3 seem to be better ski retention in situations where the ski is flexed dramatically. Tech bindings have significantly less elasticity i.
The pins just slide around in the recess of the boot. The pre-load idea is a little misleading. You need pounds of force to compress it by an inch, and pounds of force to compress it by 2 inches. Now if you preload the spring by compressing it an inch, it will still take pounds of force to compress it another inch. By preloading the spring, you are effectively increasing the spring rate. A softer spring with lots of preload keeps the same slope k value as if it had no preload, but is harder to move initially because you are overcoming the preload displacement restorative force , and the spring rate.
Or to put it another way, preload is simply shifting where on the x axis along the spring curve the motion is starting. But you still have to overcome the stored potential energy created by the preload to move the spring initially. Hi marshal, I think that your model assumes that no matter what setting, the elastic travel in binding will always reach maximum compression of the spring.
In stating that you only shift the start of motion on the X axis, you may be ignoring that the end of motion before release may be shifted as well. In other words that the releasing part of binding traveled to position where it no longer fixes the boot in the binding, while the spring was not yet fully compressed.
By pre-loading the longer spring, you would use different section of the X-axis e. This example, and those that follow, assume that the joystick is represented by the class Joystick with instance variables as defined in the interface shown in Listing 1.
Listing 1 Interface for the Joystick class. In its bind:toObject:withKeyPath:options: method an object must as a minimum do the following:. Register as an observer of the keypath of the object to which it is bound so that it receives notification of changes.
Listing 2 Partial implementation of the bind:toObject:withKeyPath:options method for the Joystick class. This partial implementation does not record binding options other than a value transformer although it may simply be that the binding does not allow for them. It nevertheless illustrates the basic principles of establishing a binding.
Notice in particular the contextual information passed in the addObserver:forKeyPath:options:context: message; this is returned in the observeValueForKeyPath:ofObject:change:context: method and can be used to determine which binding is affected by the value update.
As noted earlier, there are two aspects to change management—responding to view-initiated changes that must be propagated ultimately to the model, and responding to model-initiated changes that must be reflected in the view.
If the value associated with angle changes—typically when a user clicks or drags the mouse within the view—the joystick should pass the new value to the controller using KVC, as illustrated in Figure 4. The joystick should therefore respond to user input as follows:. Listing 3 shows a partial implementation of an update method for the Joystick class. The excerpt deals just with the angle binding. It illustrates the use of key-value coding to communicate the new value transformed by the value transformer if appropriate to the observed object.
Listing 3 Update method for the Joystick class. Note that this example omits several important details, such as editor registration and checking that the value transformer allows reverse transformations. Observed objects notify their observers by sending them an observeValueForKeyPath:ofObject:change:context: message.
Listing 4 shows a partial implementation for the Joystick class for handling the observer notifications that result. The fundamental requirement of the observeValueForKeyPath:ofObject:change:context: method is that the value associated with the relevant attribute is updated.
Listing 4 Observing method for the Joystick class. In most controls the display method alters the visual representation depending on the current selection. All Rights Reserved. Terms of Use Privacy Policy Updated: To submit a product bug or enhancement request, please visit the Bug Reporter page. Documentation Archive Developer Search.
Next Previous. Sending feedback…. Please try submitting your feedback later. Thank you for providing feedback! Your input helps improve our developer documentation. How helpful is this document? How can we improve this document? Fix typos or links Fix incorrect information Add or update code samples Add or update illustrations Add information about When you put your foot into the binding, the boot presses down on the brake pedal which lifts the brakes out of the snow, and tucks them in under the ski boot so that they are out of the way while skiing.
The brakes stay in this position as long as the boot is in the binding, but as soon as the boot is released, the brakes spring back into their extended position. Brakes need to be matched to the ski they are mounted on, as different width skis need different width brakes in order for them to reach into the snow properly and fold away without being obstructed, or sticking out too much. The anti friction device is the area or mechanism that sits under the front of the ski boot and minimises lateral friction between the ski boot and the binding.
The purpose of AFDs is to ensure sideways forces from the ski boot are transmitted into the toe cup and not the base of the binding, and to let the ski boot slide sideways as easily as possible when the toe cup releases the boot. There are several different types of AFDs that can be found on ski bindings. Some bindings have a conveyor belt like system like the Mechanics of Sport bindings, whereas others have a spring loaded plate that will move sideways with the boot, and some just have a shiny metallic area that has low friction.
Most bindings also have rollers inside the toe cup to further ensure that the boot will release easily. Riser plates are plates that go between the binding and the ski, so that the binding is mounted higher above the ski. Riser plates enable more pressure to be put on the edges and make ski boots drag in the snow less on leant over turns. They are often found on skis that are intended to perform well on hard or icy snow. Some skis have systems built into their topsheets that require specific integrated bindings to be mounted on the skis.
Some advantages this can bring are that how the bindings are mounted can be easily changed and adjusted, or bindings can even be swapped over. For most people buying skis, these advantages are not of any real importance. A standard non-specific binding that can be mounted on any flat surfaced ski is often as good as any, and can give you more choice.
When a ski bends, the toe and heel housings of the binding get closer together, but the sole of the ski boot doesn't bend or change length. Because of this ski bindings are designed so that the heel housing is sprung, and will slide along the heel track as the ski bends. This enables the binding to adjust to the boot as the ski bends, and ensures an even forward pressure is always applied to the heel of the ski boot so that the boot is always held tightly and uniformly.
Ski bindings are also built to dampen vibrations coming from the skis. Most bindings do this through the materials they are built of, but some use more elaborate damping systems often contained in the riser plate. The materials a binding is made of can effect how strong, durable, shock absorbing, power transmitting, and light your bindings are.
Generally speaking, the better you are at skiing the more you will need your bindings made of stronger more expensive materials, as the forces the binding will need to deal with are larger. Bindings are designed to let the toe and heel of the boot move within them to an extent before they release the boot. This provides a certain amount of shock absorbtion, and stops the skis from being released inadvertently as often.
0コメント