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K-Ride Alpine Ski Boot

Sponsored by Steven Sakofsky

Background:

For thousands of years, skis have been used by people to better move across snow and ice. Traditionally used just as an effective means of transportation in these conditions, more recent times have seen the rise of alpine skiing as a recreational activity. According to Snowsports Industries America (SIA), in 2013 to 2014, over 9,004,000 people visited a winter resort to ski in the United States. In the same year, 93,000 ski boots were sold, with an annual revenue of over $37 million. As the popularity of recreational skiing grows, increasing effort have been put into the design of ski boots to maximize comfort, safety, and performance.

Our sponsor, Steven Sakofsky, has been an avid skier his entire life, and has sought to improve upon the shortcomings of the current ski boot design. His proposed solution splits the ski boot into two pieces, a cuff rigidly attached to the leg and a shoe rigidly attached to the foot. By designing a suspension system to attach the two components and control the skier’s motion, Steven anticipates drastic improvements in both safety and performance over the current boot.

The rigidity of the current boot creates a number of safety concerns. Shin injuries frequently occur due to impact with the top of the boot. Hip and knee injuries come about due to the immobilization of the ankle, causing any turning and twisting of the leg and foot to be carried through the knee and hip. Additionally, performance may suffer. A skier could better initiate and carry out a turn if some motion about the ankle was allowable. Also, since movement of the boot is carried out through the flexing of the rigid plastic exterior, different temperatures will alter the boot’s performance as the properties of plastics changes with temperature. The colder the temperature, the stiffer the boot, and the warmer the temperature the looser the boot.

Problem Definition:

The current ski boot is made up of one rigid shell, an inside liner, and a few buckles to tighten the boot. This singular exterior system does not allow much motion, if any, to the skier. Therefore, most skiers experience knee or hip injuries from the transfer of force from the ski throughout the leg.

Figure 1: Typical design of a current ski boot.

Project Objective:

Our objective is to design and prototype a ski boot that will allow for a larger range of motion, yet still provide the structural support needed for skiing.

High Priority Objectives

    • Increase range of motion to allow for controlled forward and lateral flex

    • Elastic properties to return to original position

    • Limit range of motion to preserve safe ankle movement

    • Adjustable stiffness

Second Priority Objectives

    • Light

    • Easy Entry

    • No slipping up and down the leg

    • Mobility

    • Glove-like fit for each foot

    • Keep heels grounded

Other Constraints and Issues

    • Structural support

    • Needs to be form-fitting for different feet

  • Needs to function in a cold and wet environment

  • Maintain or improve safety that exists in current ski boots

Final Design: