Light, Fast, Simple, Convenient, The Miguelito

 In my Design and Engineering class we have been learning about bikes and their different parts. We learned about gears and how they affect the speed and facility of pedaling a bike. We learned about all the different types of bikes from e-bikes to single gear bikes. As part of the class we also went on various field experiences to see different types of bikes in action. As the end of the term came around it was time to start designing and building our own bikes, but not just any type, we were to design for a target persona. So we partnered up and got to designing. 

Our Persona

Our assigned persona is a 12 year boy named Miguel who lives in Spain. His main need for a bike is to ride 1.5 miles every weekday to get to school. He lives in a place where the streets are narrow and made of cobblestone, and he has to worry about possible vandalism. We must also keep in mind he lives on the third floor of his building meaning he must carry his bike up stairs. At last we had to keep in mind that the streets he lives in get very busy and so bumping into people was a real worry. 

Now that we had our persona it was time to start brainstorming and sketching our design ideas. 

Designing

In order to design a bike tailored to our persona's needs we had to keep in mind every aspect of his terrain and situation. This meant we had to carefully choose materials, measurements, and weight for the bike we created. After some sketching and brainstorming we came up with a final design we thought met all of Miguel's needs. 

Our final design would be a 3-D printed bike made out of nylon powder. Nylon powder is lighter but as strong as steel so it was the perfect material for our bike. The handles would be curved for aerodynamic and space efficient reasons. The wheels would have spikes shaped like a lawn wind spinner as we believe this would maximize the speed of the bike. Our bike would be coated with a spray-paint proof wrap so that if vandalized it could easily be washed off with water. It would have comfortable seating and a detachable basket in the back in case storage was needed. We decided to make it fold-able in case he needed to store it away in a tight space. At last in order to make Miguel's presence clear on the streets and minimize the dangers of him bumping into people we added a megaphone to announce he is coming through and we added lights on both the front and back. With our design done we needed one more thing, a name. So after very intense thinking my partner and I came up with THE MIGUELITO, in honor to our targeted user. 

(Final Sketch, EM and AAG 2021)

(our digital sketch, EM and AAG 2021)

Mathematical side 

With our design done it was time to get into the measurements and math behind our bike. Our bike would be lighter than an average bike and it would have smaller wheels than an average one since our user, Miguel, was a 12 year old boy and not a full grown adult. Here are our calculations and measurements:

Wheel 

radius: 11 inches

diameter: 22 inches 

circumference:  2π(11) = 69.11 inches 

# of wheel rotations to travel 1.5 miles 

1.5 miles = 95040 inches 

circumference = 69.11

95040/69.11 = 1375.19 

Average speed of bike: 

12 mph (max speed 18 mph) 

12 miles = 19312.1 meters 

1 hour = 60 min 

19312,1/60 = 321.868 meters per minute 

60 min = 60 seconds 

321.868 / 60 = 5.36 meters per second

Velocity = 5.36 meters per second 

Weight

Miguel (average 12 year old boy) : 103 pounds 

Our bike: 12 pounds 

Miguel + bike = 115 pounds 

115 lb = 53.16 kg 

Average Kinetic energy

1/2(52.16 kg) (5.36)^2 = 749.27 

KE = 749.27 J

Building 

With all our mathematics and designing done it was time to design a prototype and a model to represent what our bike would look like. So with some cardboard, hot glue, scissors, straws and aluminum foil we got to building. Our final result looked like this:

Conclusion

With that our project came to wrap and we hope this bike will fully serve Miguel and attend to his needs. After all cycling can be more important than it seems as a cyclist I once interviewed said "Biking gives me a sense of freedom and lets me escape into my own world". Thank you for reading, until next time!