ENGS 171 Industrial Ecology Redesigning the Bicycle Alan Salas, Kevin Dahms, Jess Zarker, Jose Ordonez, Robbie Moss Recap from last time 25000.00 Water Use Audit Water Use (kg) 20000.00 15000.00 10000.00 5000.00 0.00 Materials Manufacture Transport Phase Use Disposal/End of Life % of Total CO2 Materials: Components with Highest Embodied CO2 20 18 16 14 12 10 8 6 4 2 0 Frame Wheels Air Tube Fork Handle Crank Rear Front Bar Wheel Wheel Frame Frame Part 2: Redesign Design Requirements Seat Mast Tube FUNCTION: To support the weight of the person. Acts as a column in compression OBJECTIVES: Ideally, minimize environmental impact and mass CONSTRAINTS: Recyclable High strength and stiffness FREE VARIABLES: Material choice, shape, color Indices For minimizing environmental impact (embodied energy and CO2) Minimizing Embodied Energy Minimize Hmρ/ E1/2 for stiffness Minimize Hmρ/ σy for strength Minimizing CO2 Minimize CO2ρ/ E1/2 for stiffness Minimize CO2ρ/ σy for strength Indices for other components Part Configuration Function(s) Constraint(s) 1 Beam (loaded in Provide support; link bending) Fork between handlebar 2 Columns (in and front wheel compression) 6 Beams (loaded in bending) Provide structural Frame 1 Column (in support for bike compression) High stiffness, high strength Give direction, 1 Beam (loaded in provide stability, bending) support part of Handlebar 1 Column (in rider's weight, compression) platform for break handles Seat Mast 1 Column (in Support rider's Tube compression) weight Objective(s) Minimize: mass, embodied energy, carbon emissions Indices for other components Material Selection Analysis for seat mast tube (modeled as a column) Material Selection Lower embodied energy! Low-alloy steel Bamboo! Material Selection Low-alloy steel Lower CO2 Bamboo! Material Selection Lower density Bamboo! Low-alloy steel Trade-off Strategies Mass vs. Cost Cheaper Lowalloy steel Bamboo, Softwood and Hardwood Mass vs. Embodied Energy Less embodied energy Lowalloy steel Bamboo, Softwood and Hardwood Cost vs. CO2 Less CO2 Low-alloy steel Bamboo, Softwood and Hardwood Cost vs. Embodied Energy Less embodied energy Low-alloy steel Bamboo, Softwood and Hardwood Shape 4.5 mm 29 mm 38 mm Shape - These specifications are for Iron bamboo, which is the strongest type - If it is a more flexible bamboo, use wider and thicker tubing - If internal diameter is less than 29 mm, there will be a hoop stress, which we didn’t look into carefully in this analysis. http://www.useful-arts.com/sua/instructions/bamboobikekit/harvest/ Use Phase Analysis • Negligible environmental impact • NEXT Bike • Maintenance: paint, wheels, lost accessories, oil • Once child grows, bike becomes obsolete Use Phase Analysis (cont.) • BamBIKE: • Introduce a service program • Convert the product into a service • Incentive: offer free repairs (only cost is purchasing the parts), offer discounts, etc. • Return old bike, obtain new larger bike at a discount “If your child grows faster than bamboo, we have a solution for you!” Discussion of Redesign Frame Joints + bamboo Fork Handle bar Seat tube Eco-Audit of redesigned bike 500 400 Original 34% reduction New Design Energy (MJ) 300 2nd Life (Remanufactured) 200 100 0 Material -100 -200 -300 Manufacture Transport Use Disposal End of Life potential CO2 of Entire process 25 CO2 (kg) 20 Original 40% reduction 15 New Design 10 2nd Life (Remanufactured) 5 0 Material -5 -10 -15 Manufacture Transport Use Disposal End of Life potential Specifically looking at components 70 60 Original 75% reduction Energy ( MJ ) 50 New Design 40 30 20 87% 10 0 Frame Fork Handlebars Seat Tube CO2 of materials 4.5 4 74% reduction 3.5 Original CO2 ( kg ) 3 New Design 2.5 2 1.5 1 87% 0.5 0 Frame Fork Handlebars Seat Tube Water-audit of redesigned bike 25000 Water Audit: Existing vs. Redesign 20000 Why isn’t there a significant change??? kg of Water 15000 Original Redesign 10000 5000 0 Materials Manufacture Transport Use End of Life Economic Analysis • Materials: • Low alloy steel • 0.89-0.93 USD/kg • At 3.68 kg, price is $3.35 • Bamboo • 1.37-2.05 USD/kg • At 0.4 kg, price is $0.82 • BUT, labor is a problem: • More labor intensive to assemble BamBIKE, so higher costs are associated • This is why it is currently only offered to very specialized, high end consumers Economic Analysis • CNN article published today about a bamboo bike company located in Zambia: “Each frame takes between 40 and 60 man hours to make […] Every piece of bamboo is having different colors, different bend, so every frame is unique." • That explains the high costs, and why these “high-end, lightweight bicycles” have “a price tag of around $900” and are “primarily aimed at the international market”. http://edition.cnn.com/2012/05/31/business/bamboo-bicycles-zambia-zambikes/index.html?hpt=hp_c4 Considering Aesthetics: Paint and Plastics Aesthetics are a major feature refractive quality of paint, extra features (painted plastic), logo designs Aesthetics are also subjective; malleable • Don’t outweigh the environmental impacts: • Greenhouse gas emissions: VOCs, CO2, NOx, SOx , and PM • Health Concerns for workers • “Eco-Design” Water-based paint Water-based non-toxic wood varnish logo Conclusions and Recommendations Findings • Bamboo is an appropriate substitute for steel • Saving 91 MJ per bike means saving energy of 245 bananas per unit!!! Considerations • Industrial infrastructure is currently nonexistent • This is the foundation for a sustainable lifestyle Conclusions and Recommendations There are other important benefits of bamboo that could be further exploited: “One of nature's fastest growing resources” “Has great shock absorbing abilities that contribute to a smooth and eco-friendly ride” http://edition.cnn.com/2012/05/31/business/bamboo-bicycles-zambia-zambikes/index.html?hpt=hp_c4 Moving forward… Hemp Wood Wood and ideally… DIAMOND! Questions?