Limitations of current alpine touring ski bindings.

OBJECTIVES

Quantify various parameters of safety and performance of modern alpine touring bindings in particular their release characteristics.

DESIGN

For n = 16 alpine touring bindings from season 2018/19 and 2019/20, we performed multiple tests under standardized conditions using identical test soles built from one market relevant alpine touring boot.

METHODS

Referring to the standard of the International Organization for Standardization for alpine touring bindings ISO 13992 we measured both the impact tolerance as well as the influence of forward and backward lean on the bindings' twist release behavior. Further rigidity measurements were performed to determine the torsional and deflection stiffness of the ski-boot-binding system. Additionally, we determined the accordance of the bindings' indicator settings with the real release values. In order to test the consistency of the bindings' twist release behavior, the torque deviation over 25 releases was measured.

RESULTS

The bindings showed very different behavior. Nine out of the sixteen bindings exceeded the given limit for twist release in case of additional backward lean. Especially lightweight Tech/Pin bindings did not show sufficient rebound elasticity when being impacted laterally. Some bindings revealed imprecise indicator setting values.

CONCLUSION

A comparable level of reliable release characteristics, as it is true for alpine ski bindings, should not be expected from alpine touring equipment - especially with respect to release under combined loads. Low impact tolerance might also be a safety issue leading to inadvertent releases.