Trident Lock

In Praxis I, teams of 4 students are guided through the design of a consumer product from the initial brainstorming to the pitch of the final product in a design critique. My team was charged with the problem of bike theft, a very broad problem, yet still manageable for a group of students. We immediately agreed that the main stakeholders in this project are the cyclists themselves, as they would be the primary users and maintainers of the lock. This lead us to prioritize functionality in terms of how well the lock secures the bike, and usability as our main design goals. Safety was of course also a consideration, however we decided that as long as the lock possessed a baseline level of safety, additional investment was pointless.

A quick decomposition of different approaches to solving the problem based on the initial concepts generated.

To approach the problem we first generated a diverse set of solutions, from which we decided that the problem of bike theft could be approached from two distinct directions: preventing theft, and deterring theft. Initially, a third frame consisting of recuperating the bicycle after the theft was considered, however after research we decided this was a solved problem, so we focused on the other two.

It is this idea of concept generation and research informing the analysis of the problem that makes design such a non-linear process, which is reflected in how I approach problems. In this situation the initial framing was left vague, and through many iterations of convergence and divergence, we were able to narrow down the framing until the concepts were similar enough to be compared. It is a feedback loop of sorts, in which an initial guess is improved with every iteration.

A concept that focusses on imobilizing the bike, a precursor to the trident lock

An integrated swivelling lock concept. Initially selected but later rejected due to incompatibility

A concept for a hiddent bike alarm.

An articulated plate chain concept

It was at this stage that we began to do research on the designs that we had selected, which was crucial because I discovered that several of our concepts had already been fully implemented. Following this, we had to loop back to the problem analysis phase and adjust the framing so that the problem was not already solved.

Using decision making tools my team decided on a resilient, swiveling, bike mounted locking system. Upon a bit of testing, we realized that this design would not in fact be compatible with existing bike lock infrastructure, so we decided to step back and analyze the other concepts we had previously generated. Using the knowledge we gained from testing this design, we decided on a bike-rack independent design that immobilizes and secures the wheel to the frame.

We started with a prototype consisting of two disks linked by more than 10 posts, pictured to the left, however through the failure of the last design, we realized the importance of the adaptability of the design. For this reason we added adaptability to a wide range of bicycles to the list of design goals.

Prioritizing for usability and adaptability, we developed a series of prototypes, both physical and computerized, of increasing fidelity, until we arrived at the design for our final product, dubbed the Trident Lock. The Trident Lock consists of two Y-shaped devices that are mounted to the fork of the bicycle using a special skewer bolt. Securing the bike is then as simple as aligning the wheel and sliding three rods into place. This immobilizes the wheel, preventing the thief from riding the bike away, deterring theft, and preventing the removal of the front wheel.