Professor Kevin Shankwiler of GeorgiaTech has been teaching a third-year bicycle design studio for the past four years. The 8-week course is primarily focused on understanding product systems design and exploring opportunities for innovation in commuter bike design. David Hotard was among the 12 students in the SRAM-sponsored fall studio, which culminated with four teams (of three students each) developing very different bikes. He worked with Matthew Campbell and Edwin Collier on reimagining the hubless wheel as a cargo space; here Hotard shares how they arrived at the final product.
"Transport" is a commuter bike design project sponsored by SRAM. Although panniers and saddle bags are on the market to make commuting easier, we found that many cyclists prefer to ride with a traditional backpack. This doesn't mean that a backpack is comfortable; it's just more practical than the panniers that clip to a rack. We discovered that many commuters didn't want a bag that felt like a dedicated commuting bag but rather a bag that would work in any scenario. We started to look at what we do with bags when we're traveling by car, plane, train, and other means and realized that there is almost always a compartment for them. We realized that what commuters wanted was that compartment... on their bike. Research on futuristic bike concepts inspired us to use the negative space of the much-debated hubless wheel for our trunk. The result shows that a trunk in the wheel could easily accommodate various backpacks and might well be very feasible solution. We were also happy to see that Yale mechanical engineering students built a bike with a hubless wheel while we were in the midst of our project.
We researched the hubless wheel to the extent that we could validate that it is technologically feasible; besides the Yale project, the Lunartic was an inspiration to us. Although it may be more expensive to produce and currently less structurally sound than a traditional wheel, we know that in many cases people are willing to pay more for a design that satisfies their needs. We did a lot of research looking at concept bikes, current products and observing users. The hubless wheel storage system brought those three areas of research together by giving commuters the ability to travel with any bag, not just a rack-able bag, and also showed a practical purpose for a hubless wheel concept.
We were given a brief with exact objectives:
1.) To learn about the fundamental nature of product systems, that is the relationship and interdependence between products to products (function, integration and context).
2.) To understand the relationship between a product, it's component make up, and it's larger context.
3.) To build literacy and competence with digital tools as a component of prototyping.
4.) To understand the links between intent, material, and process.
5. To explore existing products and built-in technologies to develop a comprehensive understanding of product design and integrated machinery.
6.) To adopt an open ended approach to identify problems and identify opportunities for design.
Challenge: Urban cycling is the current fertile ground for bicycle innovation. Why? Mountain biking and road cycling markets have matured greatly, leading to evolutionary design development based mostly around frame materials, suspension performance, and weight reduction. The UCI (Union Cycliste Internationale) governs (and limits) specifications for competitive road bikes, which has directly impeded the development of non-triangle main frames. Urban cycling, on the other hand, is ripe for innovation. Few bikes have been designed specifically for riding in the urban context. This type of riding includes commuting, couriering, cargo hauling, and others. Your goal is to get more people to ride a bicycle to work. Make commuting to work by bicycle more enticing for people who currently use other means.
We made many models: 1/8-scale laser-cut chipboard, foam, MDF and full-scale cardboard/foam models.
The final prototype was crafted out of Baltic birch plywood in several pieces and then glued together along with a 3D-printed headtube.
The hubless wheel was created with a bicycle rim rotating around a system of bearings.
The storage compartment was made using PET-G, vacuum-formed over a sign foam mold.
The hubless wheel prototype does spin; it rotates around a system of six bearings, similar to the Lunartic design.
The rear wheel was also made of wood and built around an internally geared hub, which is a relatively low maintenance option for commuters.
We added plasma-cut steel support in high-stress areas, then applied Bondo and lots of sanding. The frame was painted with filler primer and automotive paint.
I'm not quite sure about the weight; it feels a little heavier than my road bike so I would guess it is around 25lbs.
The wheel alone is very lightweight since the storage compartment is made out of PET-G—it's comparable to the weight of an OEM road bike wheel.
The final prototype is not rideable since it is made out of wood.
We've considered continuing the project to make the hubless wheel and fork subsystem to put on a rideable bike.