Final Design

The tandem trike final design is comprised both titanium and carbon composite. The entirety of the tricycle, apart from the base tube, is made of ATI 3-2.5 Titanium, Grade 9 CWSR. The carbon composite tube laminate is an 8552/AS4 (40%/60% vol) (32.7%/67.3% weight) and has a lay-up pattern of [0,0,0,-45,45]s. The key components that comprise the final design are the front assembly, the carbon base tube, the middle boom and seats, and the push bar.

Front Assembly:

    Functional Requirements:

        Angle front boom inline with pilot’s legs

        Support pilot’s weight, ~900 N (200 lbs)

        Securely welded to titanium-carbon interface

        Withstand stresses from pilot pedaling and moment on side of trike

 Functional Requirements:

        Comfort and functionality for Lance

        Seat back angle between 20º and 60º

        Seat buckets Lance so that he does not slide forward when decelerating

        Boom needs to be sturdy and at optimal position for Lance to pedal with his hands

    Functional Requirements:

        Allow riders to push trike while on their own bikes

        Transmit force to body of trike

        Maintain distance between Lance and the pushing rider

        Design for max pushing force of 900 N (200 lbs)

        Removable for transport of trike

        Securely attached