V.2.

=**Product Contract v2**=


 * Product Description:**


 * Intended Customers:** Current manual wheelchair users


 * Market:**


 * **Customer Need** || **Product Attribute(s)** || **Engineering Specification(s)** ||
 * Transportability || added weight || < 10 lbs additional weight ||
 * || time for wheel release || ? Seconds ||
 * || no impact on wheelchair ability to collapse || Time to fold is same ||
 * Unobtrusive appearance ? || Minimal ??? || max hub size??? ||
 * || number of rims on wheel || 1 ||
 * Easier traversal of a wide array of surfaces and slopes || mechanical advantages || F_hill = F_flat + F_additional spec different slopes, gears needed ||
 * || uphill wheelchair feature || allows forward only motion when engaged ||
 * || braking system || brake force? ||
 * Ability to effectively shift between configurations at any time. || shift on the fly || binary: yes ||
 * || time required for user to shift || less than 1 second ||
 * || time required for user to engage/disengage uphill feature || less than 2 seconds ||
 * || time required for user to engage brake || less than 1 second ||
 * || number of hands required to shift || 1 hand ||
 * Product lifetime || lasts as long as wheelchair || product last longer than 5 years ||
 * Device is ergonomic to use || Rim optimally sized for comfort and low arm stress || distance from shoulder to rim is XX ||
 * || Low backlash || less than 20 degrees backlash ||
 * maintain manueverability of traditional wheelchair || wheels can be driven backwards || binary: yes ||
 * || wheelchair width || meets ADA width requirements for a normal wheelchair ||