Mountain Bike Design

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Todd Gregory test riding a new DW-Spot in Bootleg Canyon, Interbike 2008

In 2007, Gregory Designs began applying the principles of mechanical engineering to a hobby and passion:  mountain biking.  We approached a high-end frame builder, Turner Suspension Bicycles, and offered our engineering and analysis services.  A bit hesitant at first, Turner Bikes sent us the drawings for a small linkage part that was experiencing a number of failures, causing a warranty expense for the business.  Without any prior knowledge of how the part was failing, Gregory Designs demonstrated precisely where the failure was occurring.

The projects quickly progressed from single linkage designs and analyses to complete frame designs.  The goal of our work together was to 1. create stiffer and stronger parts, 2. to decrease weight where possible, and 3. to reduce warranty claims.  Turners’ bikes are renowned for their durability, so Gregory Designs is a proud partner in carrying on the tradition of robust design.

In model year 2009, Turner Bikes released a complete new line of bike frames utilizing the patented “DW link” technology.  Patent owner Dave Weagle developed a set of kinematics equations that produce the ideal suspension dynamics for a mountain bike.  The design allows Turner and Weagle to independently tune the 1. Linkage Rate, 2. Pedaling induced suspension behavior (aka Anti-Squat), and 3. Braking induced suspension movement (aka Brake-Jack).  Gregory Designs provided 3D modelling of the new bicycle frames, links, and machined parts in addition to a thorough FEA analysis of these components.   The new bikes were received by the mountain biking community with rave reviews for their ride qualities and their frame stiffness.  After several year of production, we are happy to report a very limited number of warranty issues with the new designs.