Friday, 14 October 2011

Binding Wedges - a literature review

Disclaimer

This write-up is intended as a literature review and, as such, does not include any new or original work. See the list of works cited at the end for sources.

Introduction

Last winter, Salomon introduced a binding wedge to the retail market. This product is installed under the skate binding and provides a 5mm lift to the toe relative to the back of the foot. This translates to approximately one degree of lift. For the 2011-2012 season, Rottefella has released a NIS compatible version of this product for retail sale. There has been a lot of confusion within both the racer and consumer population as to what this product is purported to do, what the actual testing results show, and what is recommended in terms of whether or not this is a good product. Accordingly, a lot has been written on this topic and we have compiled a review of the current literature.

Advertised Benefits

According to both Salomon and Rottefella, the binding wedge improves ski acceleration and edge control by increasing the efficiency, power, and length of each skate stride (Salomon, Product News). In a February 2010 blog post, Salomon notes that this is accomplished as the wedge increases ankle flexion, thus allowing for a more powerful beginning of each skate stoke - In other words, by increasing the angle the ankle, the ski 'squirts' ahead, up the hill (or ahead), increasing the 'free-glide' feeling (Salomon, Product News). Neither manufacturer recommends the use of the wedge in any specific conditions. Rather, both binding companies simply indicate an overall net benefit to the athlete.

Testing Experience

As with any technical ski product, it has rapidly become clear that the advertised benefits are not nearly so obvious when out on the trails. Mark Waechter of Nordic Ultra Tune notes that for a few sessions the effect is somewhat noticeable, but eventually good skiers will adapt and the wedge may not offer a long term benefit (Waechter, NIS Xcelerator Wedge). Similarly, Zach Caldwell of Caldwell Sport notes that after some early testing, his results were not conclusive (Caldwell, Binding Wedges).

Given the inconclusive nature of the early testing results, we must look to recent World Cup racing as the proving ground for this product. At the 2011 Tour De Ski, Zach was able to test multiple pairs of race skis, on race day, with and without wedges (Caldwell, Binding Wedges). In this article, Zach indicates that this was the first time the addition of binding wedges obviously resulted in faster skis. Therefore, it is evident that the wedges offer a benefit in certain situations and Zach suggests that we must consider the athlete, the ski, and the conditions in the determination of those situations (Caldwell, Oslo WM Tech Notes).

The Athlete

Unquestionably, the addition of binding wedges changes the geometry of the binding platform. Further, it is clear that some athletes like this change and some do not. Utilizing the pause button while watching some World Cup footage will quickly reveal that Lukas Bauer does not like the wedge, while Ivan Babikov has it installed in virtually all of his skis. Given the increased ankle flexion generated by the wedge (Salomon, Product News), it appears that skiers with good flexibility will adapt with relative ease (Caldwell, Oslo WM Tech Notes). On the other hand, athletes who have some stiffness may find their technique disrupted in an undesirable way and their shins getting sore (Caldwell, Oslo WM Tech Notes).

The Ski

By encouraging the athlete to weight the foot a bit further back (Waechter, NIS Xcelerator Wedge), wedges may reduce the load on the forebody of the ski. For those ski models that carry significant tension in the forebody (Fischer Carbonlite Skate, Madshus 118 Hard Pack), wedges may have a noticeable impact on the feel of the ski. This could be especially useful in softer conditions to reduce the ploughing effect these models can sometimes have.

The Conditions

Based on testing results, Zach has indicated that the wedges generally result in an improved feel in soft, wet snow (Caldwell, Oslo WM Tech Notes). In conversations I have had with Mark Waechter, it appears that he is of the same opinion. In addition, there are indications that the wedges may cause a reduction in stability in hard packed conditions. This is logical given the reduced forebody load noted above.

This position is consistent with the findings of the Fischer racing department. Frequently, the Fischer service staff have not seen a benefit from the wedges, however in soft and wet conditions they have found installing the wedges to make a significant difference (Caldwell, Oslo WM Tech Notes).

Conversely, Knut Nystad, chief of the Norwegian Ski Federation Service Team, has an entirely different experience. Knut indicates that it seems like binding wedges make the ski perform better, particularly in hard conditions (Nystad, Knut’sCorner). This position, however, is not consistent with the general consensus as most testing indicates that the harder the snow, and the faster the conditions, the less difference the wedges seem to make (Cramer, What’s the deal with binding wedges?)

Conclusion

The bottom line conclusion is this:

- In soft, warm conditions it is generally accepted that the wedges will improve performance and will not be a liability. We would recommend installing the wedges on skate skis intended for warm conditions.

- In colder, harder conditions it is not clear that the wedges will improve performance and they may result in reduced stability. We would approach wedges on skate skis intended for cold, hard conditions with caution.

However, as Mark points out, given the modest price of the wedges and the minimal impact on ski setup (installation is fast, easy, and non-invasive), this is a product that anyone could try (Waechter, Weighing in on Wing Wedges). 


Works Cited

Caldwell, Zach. "Boulder Nordic Sport - Binding Wedges." Boulder Nordic Sport Home. 18 Jan. 2011. Web. 14 Oct. 2011. -http://www.bouldernordicsport.com/Home/tabid/164/itemid/254/amid/2000/Default.aspx-.

Caldwell, Zach. "Boulder Nordic Sport - Oslo WM Tech Notes #4." Boulder Nordic Sport Home. 15 Mar. 2011. Web. 14 Oct. 2011. -http://www.bouldernordicsport.com/Home/tabid/164/itemid/316/amid/2000/Default.aspx-.

Cramer, Bruce. "What’s the deal with binding wedges?" Editorial. Boulder Nordic Sport Catalog - Winter 2011-12 Oct. 2011: 6. Boulder Nordic Sport, Oct. 2011. Web. 14 Oct. 2011. -http://www.bouldernordicsport.com/images/catalog/BNS_1112_web.pdf-.

Nystad, Knut. "Knut's Corner." Editorial. Boulder Nordic Sport Catalog - Winter 2011-12 Oct. 2011: 3. Boulder Nordic Sport, Oct. 2011. Web. 14 Oct. 2011. -http://www.bouldernordicsport.com/images/catalog/BNS_1112_web.pdf-.

Salomon. "Product News: SNS Wedge." Salomon Nordic News. 18 Feb. 2010. Web. 14 Oct. 2011. -http://salomonnordic.blogspot.com/2010/02/product-news-sns-wedge.html-.

Waechter, Mark. "NIS Xcelerator Wedge - Details and Photos." Nordic Ultratune Blog. 2 Mar. 2011. Web. 14 Oct. 2011. -http://blog.ultratune.net/2011/03/nis-xcelerator-wedge-details-and-photos.html-.

Waechter, Mark. "Weighing in on Wing Wedges." Nordic Ultratune Blog. 1 Feb. 2011. Web. 14 Oct. 2011. -http://blog.ultratune.net/2011/02/weighing-in-on-wing-wedges.html-.