I spend a lot of time trying to explain this in writing. Sometimes a video is better. Here you go. See below for clarifications in writing.
1. This video illustrates checks you can do on a “classic” tech binding, meaning it has pins that insert in boot at toe and heel, releases to the side at the heel, and does NOT have a rotating toe. Nonetheless, these concepts can apply to bindings with rotating toe, and the lever release check works on nearly any binding, though you should only use the lever check on vertical release settings around 6 or lower, to prevent damage to ski, binding, or boot. I miss-stated this in the video.
2. The CONCEPT of these checks does apply to bindings such as Radical 2.0 with rotating toe and Kingpin with different type of upward release, but what you see during such checks on such bindings will be different than what I illustrate in this video. MORE, with bindings such as Kingpin you may need to test lateral release function with binding set to your normal release settings as the Kingpin lateral release spring needs to apply force to the boot to overcome friction at the brake AFD under the boot heel. Note that classic tech binding lateral release function can also be tested at your normal settings, it is the vertical release function test using a lever that requires lower settings, to prevent use of excessive force.
3. These evaluations are not used for setting release values, they are simply ways to evaluate if the binding actually releases and has correct return-to-center function as well as a modicum of elasticity.
4. These tests should be done at moderate release value settings so as not to place undue force on binding components. Settings around 6 or lower seem to work well. More, be sure the correct heel gap is set for your test bindings per manufacturer specifications.
5. IMPORTANT: If you observe any problems with these functions, cause can be either the boot or the binding, or sometimes a combination of both. Evaluate using A-B testing with different boot binding combinations. For example, a guy came by here the other day with a setup that seemed to be “grabby” in side release as well as prone to pre-release. Turned out the binding toe pins were excessively worn, his boot worked fine in a newer set of bindings.
6. If any of these tests appear to require excessive force, re-evaluate before you proceed as you could damage your ski, boot, or binding.
7. By watching this video and visiting WildSnow.com you agree that you perform all such testing and evaluation at your own risk.
8. Some bindings in my experience seem to not be designed to give the smooth lateral release function as shown here, ditto for boots. If you have such a binding you’ll need to decide if having smooth release and elasticity are worth it to you, or not. Your choice.
9. Rotating toe of Radical 2.0 and Beast, and side release toe of Vipec and Trab all eliminate problems with the toe “ball and socket” joint catching or otherwise not moving freely.