Travis' Bike

For the second unit of Design and Engineering at GCE, we learned all about bikes. Throughout our internal investigation, we talked mostly about the math that goes behind different parts of the bike such as the gears and wheels. For our external investigation, we visited a design firm to learn about the design process, had a representative from Divvy come in to talk to us about bikes, and did a workshop with a representative from Dyson. Finally, for our Action Project, my partner and I were given a persona and asked to design a bike based off of their specified needs.

Bike Anatomy. (2016) LS.

Our assigned persona is a student that lives in Uptown and wants to ride the lake path to school. He lives on the third floor of his apartment so he wants a bike that is easier to carry and store in his home. He needs a bike that is light, fast, and can move effectively in the weather throughout the year.

To fulfill these needs, we designed a bike with a variety of features. For the weight and storage issue, we made the decision to use a light yet strong material, use a fixed gear mechanism, and make the bike completely collapsible. This means that the bike can be folded in half down the center to make it easier to carry up stairs and store in a small apartment. In order to make the bike fast, we made the seat higher than the handlebars to force a suicide position and used thinner tires meant for a city street. The suicide position helps him go faster because it makes him more aerodynamic. Finally, for the weather issue we made the tires heavily treaded. This would allow the bike to travel more easily across the lake shore path when it is wet. Most bikes now have either thin slick tires or thick and heavily treaded tires. We wanted to make a hybrid of both for the best of both worlds.

While some people may be hesitant to buy a new product, the reason our user should buy our model is the variety of features. In other words, let the product speak for itself. Since the bike is tailored directly to the needs of city goers, there are few other bikes that can provide what ours can. Since we have no background as bike designers, the only reason to believe that our bike is going to benefit users the most is the multitude of useful features. Also, if we look at the user that we designed this bike for specifically, he has every reason to believe in our design because the bike was built directly around his needs.

Collapsed Bike View. (2016) LS.

To make the model, we measured an existing bike and used a scale of 9 to 1. For my wheel size we used a diameter of 622 mm or about 24.5 in. This puts the circumference of the wheel at about 1954.07 mm or 76.93 in. After calculating the distance from the user's home in Uptown to GCE to be about 6.1 miles, we calculated that the amount of rotations the bike would make in one ride would be about 5023.87 rotations. You can calculate this by dividing the total distance by the circumference of the wheel. Also, the average time it takes the user to get to school is 33 mins if he is traveling at an an average of 10.91 miles per hour or 4.88 meters per second for the duration of the trip. Since the user wants to go very fast and is only going to be riding on a mostly flat surface, the best gear ratio to use would be about 44:16. This means that there is a larger gear in front and a smaller gear in back. This allows the back gear to rotate more with less peddling and lets the user go faster. Also, since the user is presumably light (being around 130-145 as a 16 year old) and has the need to go fast, the gear ratio will be beneficial.

Bike Model. (2016) TH.

During our external investigation, we interviewed people that we knew to be bikers. During my biker interview, my interviewee said something interesting that ended up helping during the design process. He said:“Although I love my fixed gear, thin tire bike, it would be more beneficial to have a bike that can work on a variety of surfaces." This quote was part of the decision to add the thin yet treaded tires to our design.

During a part of our internal investigation, we discussed kinetic and potential energy. Since there aren't many elevated portions of the lake bike path, my user wouldn't often have potential energy. However, whenever he is at the top of a hill he would have the most potential energy. When he is moving the fastest, he would have the most kinetic energy.