President, Vermont Ski Safety Equipment, Inc., Underhill Center, VT
Professor Emeritus, Rochester Institute of Technology, Rochester, NY
McClure Professor of Musculoskeletal Research, Robert T. Stafford Hall, College of Medicine, University of Vermont, Burlington, VT
(Received 29 October 2004; accepted 12 April 2005)
The objective of this study was to develop principles and practices which could improve the efficiency and reliability of alpine ski equipment rental facilities operating in compliance with ASTM or ISO rental standards.
Tests were conducted using a commercially available device to measure the release moments of boot/binding combinations, with contact areas between boot and binding alternately in clean and lubricated conditions. Bindings were also tested in combination with a test sole adjustable for length. The study provided a measure of the variability of the components of the release system and an estimate of the system variability experienced by rental facilities using various inspection, maintenance, and dispatch procedures. It also produced guidelines for reducing the need for applying correction factors to the release indicator scales of bindings in the rental inventory.
Among 60 boot/binding combinations the study found that the difference between clean and lubricated tests ranged from 0% to 34% with an overall average difference of 7%, half that observed twenty years ago. The difference in tests comparing actual boots in a lubricated condition with a test sole of the same length in a lubricated condition ranged from +3 Nm to −3 Nm with a mean and standard deviation of less than 1 Nm, a fraction of differences noted in years past. However, release value selection tables currently in common use do not accurately reflect the relationship between boot sole length, release indicator value, and the target release torque. The study found the indicator value displayed in 64 % of the most commonly used cells in these charts varied from the optimal by release indicator increments ranging from −0.5 to +2.5.
The release characteristics of modern alpine rental boot/binding combinations are more predictable and reliable than ten or twenty years ago. However, inspection, maintenance, and dispatch procedures currently in use do not take full advantage of these capabilities. A simple procedure exists for the routine documentation of boot/binding compatibility so that rental procedures can be updated to reflect the true characteristics of contemporary rental products and thereby minimize the potential for time-consuming correction procedures and improve the release retention performance of equipment dispatched to the rental customer.
Paper ID: JAI12093