A New Design Ride: Designing an Open-Source Adaptive Mountain Bike

NOEL JOYCE: Hi. My name is Noel Joyce. I'm an adjunct professor at NYU Shanghai. I'm a designer, an adaptive mountain biker, and I'm also a wheelchair enthusiast.

First, let's go back in time a little. It's hard to believe that the first bicycle, which was called a Laufmaschine or running machine, was invented by Karl Drais in 1817. So the history of the bike isn't all that long when you consider the simplicity of the machine.

And did you know that the Wright brothers, the fathers of flight, were bicycle mechanics and applied the principles of weight and construction in bicycles to the development of their aircraft? It's actually pretty amazing the impact a simple bicycle has had on the world.

We often associate the bicycle with our first feelings of speed and lightness, almost giving us the sensation of flying, the daredevils amongst us actually taking flight on these amazing machines. From BMX to mountain bikes, from racing bikes to cruisers, there's a bike for everyone and every personality.

Well, we also remember our bikes as their first personal mode of transport, machines that took us on journeys further away from home, often with friends, our first true freedom and independence, one of our earliest means of escape and adventure.

And then there's the mechanical side of the bicycle. I became fascinated with the bike at an early age. I would often cobble together Frankenstein bikes from barely functioning parts in a quest to create a faster version of what I already had.

This obsession led me to one of my first jobs working in a bike shop in my home town. I worked in a bike shop, at first part-time after school, and then full-time when I finished school, all the while riding bikes as often as I could. It would be an understatement to say that bikes are a huge part of my life.

I loved working on bikes, but another career beckoned in the military, and I joined the Irish Defense Forces. That didn't mean that I stopped biking. In fact, I continued to mountain bike to stay fit as well as for fun.

Eventually, I began participating in adventure racing on behalf of my unit. Adventure racing comprised of mountain biking, kayaking, and fell running, and it was an awesome challenge. I would ride my mountain bike as often as possible. But it was one day when I was out riding my mountain bike that life would change forever.

I'd been riding in a woods I knew well but in pretty adverse conditions. I took a fall and broke my back, leaving me paralyzed from the chest down. The impact wasn't that hard. It was just the way I fell. It was instant and I could see my knees in front of my face. I just couldn't feel my legs.

The pain was enormous, and I drifted in and out of consciousness a few times. I was unable to draw enough breath to shout for help. Luckily, my friend found me. And after many hours, I got off the mountain and to the hospital.

Life had changed massively. I could no longer perform my duties as a soldier and I had to start life over again. I would spend the next few months in rehabilitation. And I began to learn how to survive the new normal and figure out what I was going to do.

It was while I was in rehabilitation that I began to explore what I could do for work. I'd seen the difficulties for those with disabilities and wondered if I could do something to solve those problems.

At 26 years of age, I went back to education and studied industrial design at the Institute of Technology in Carlow in Ireland. At the end of my studies, I started a couple of small hardware-related startups and learned a great deal about the application of design to business. It was also the beginning of my journey and learning about design and manufacture. And I wasn't to know that this would lead me back to riding mountain bikes again in the future.

I traveled to Shenzhen, China and ended up working at HAX, a hardware startup accelerator, where I was head of design for eight years. While I was there, I worked on projects with over 200 different hardware startups. I worked on projects in industries as diverse as medical to robotics, from consumer electronics to transport. If there's an industry you can think of, I may have worked on a project in it.

In 2019, I traveled back to Ireland just before the pandemic and my career took another turn. I began the journey of teaching at NYU Shanghai during the pandemic. I taught my classes remotely from Ireland through Zoom. Hosting my classes online, I was able to teach Fusion 360 to students on the other side of the planet. Two paths I was traveling at the same time were to converge in the near future, but not how I expected.

In my work at NYU, I teach design and innovation-related subjects. My core software go-to is Fusion 360. The versatility of the software and its evolutionary development allows me to add value to my students' education. It's also the software that I would use to design, prototype, and build bikes.

Parallel to my new career at NYU Shanghai and teaching remotely, I found myself getting back onto the bike, albeit I was on three wheels instead of two. My first bike was this rigid, framed, simple affair with no assistive drive and simple components.

It was still expensive given what it was. Regular mountain bikes are expensive for something capable. Adaptive mountain bikes are frighteningly expensive. They have really crazy prices with something even reasonably capable costing between $8,000 to $10,000 USD. And for something good, it can cost up to $23,000 USD, depending on specification.

It was one day that my neighbor, seeing me riding this particular bike at my house, suggested that I try the trails near our homes. The trails in question were at Kennedy in the Slieve Bloom Mountains. We set off on Saturday morning. For the first time in 15 years, I rode down a mountain bike trail. It was terrifying and exhilarating at the same time. The adrenaline was in full flow again, and the bug had well and truly bitten. I was back on the bike.

It wasn't long before I was outriding the bike's capability, and there was frequent failures. It was a mountain bike in name only. Wheels were being destroyed because of the enormous leverage on them. Brakes were weak. Gearing was terrible for climbing. And the constant jarring and impacts on the frame were leading to cracks and breaks. It was upgrading parts and frequently in an effort to extract more performance from this bike. But, ultimately, there was no amount of upgrades that would make it last.

All this was leading to frequent repairs. Having to weld a frame back together was taking its toll on the bike. And every time it was welded back together, it was technically repaired, but it was weaker because it wasn't heat-treated. It was also taken a toll on my pocket. It was very clear that the bike was not going to last very long with the punishment it was getting. I decided to design my own bike, as I had ideas and knew what I wanted.

I began by doing a lot of this kind of stuff, taking measurements and tweaking ideas, using a mixture of CAD and sketching to come up with form factors, trying to anticipate the limiting elements of creating a hand cycle. Hand cycles are very complex variants of a bike given steering and the driver on the front fork.

And add to this suspension, and it becomes a real set of problems, requiring a multiple rounds of innovation thinking outside of the box. I began the hunt to find someone who would help me develop the ideas and concepts into a fully fledged bike.

I found a company in Spain called Carbon Master who took on my ideas and built the world's first carbon fiber, full suspension, adaptive mountain bike. Over the course of the year and with lots of back and forth conversation, this was the result. This single build took quite an effort to execute on, as there were so many unknowns involved. While the company had built many road bikes before, they had never built anything like this. I received the bike and immediately got out on the trails.

The bike offered so much more capability in range. It was equipped with an assistive drive which allowed the rider to go further distances over terrain that was a bit more difficult. There were many problems with the bike as the terrain I was venturing onto began to take its toll. While carbon fiber is a super material, when it fails, it's not a great situation. Unfortunately for me, I was about to find this out.

On a ride in the mountains on a trail I was used to, I hit a set of undulations that pitched the bike into the air at the rear. On the final impact, I heard a crack, and then the bike hit the ground and slid along the trail, splintering carbon fiber as it went. The bike had an unplanned rapid disassembly at the molecular level at one of the rear suspension structures.

One of the carbon fiber [? A-arms ?] disintegrated, leaving me stranded in the forest. It was around five kilometers from the car park and with no way out. As a wheelchair user, you don't walk out from these situations. It was scary to be in such a vulnerable position again. I say vulnerable, as it felt like the time I crashed almost 16 years before. Even though I wasn't injured, there was a feeling of helplessness at the situation.

Well, with the ingenious invention of the cable tie, we got the bike out. Can anyone guess how many cable ties did it take to get me home? The answer to that question was, every single one of them. When I got home, I reached out to the company who made the bike and I asked about having a new part made. Cost of repair, 500 euros, lead time for the part, five to six weeks.

For those with a disability, it's often the case that time is not on your side when it comes to longevity of enjoying sports. It gets more difficult more quickly due to the toll on the body. To wait six weeks is losing an enormous amount of the most precious of time when I was capable and able to use my bike.

The price was also a concern. It was difficult to accept that I had to pay over the odds just because I couldn't go anywhere else for that part. I didn't have the option of getting a new frame or going to a local bike shop for a repair. Not only this, I no longer trusted the bike. I decided I would design the same part from aluminum and have them made myself.

Within two weeks of that decision, I had the full set of four A-arms for half the price of a single carbon one. These arms were made from 7075-T6 aluminum. Admittedly, they were very simple and heavy, but I knew they wouldn't break. To me, it was a miracle that I could get back on the bike that quickly given the previous timeline for the carbon fiber part. All of this was done in Fusion 360.

More importantly-- importantly, what I knew now was that I could solve the problem for myself and decided that I would design an entire bike to be easier to build, faster to build, affordable to build. And I decided when it was finished, the files would be made open source so no one who built one would find themselves in the helpless position I had not long ago been in.

Utilizing Fusion 360, I designed the entire bike from the beginning with new ideas and concepts. I designed the most complex variant, a full suspension bike on which we could work backwards to simplify. Over the next few months, I spent hundreds of hours in Fusion 360, working out problems, creating specific geometry based on the characteristics I wanted from the bike, and figuring out how it would be assembled. This would be the beginning of the open source adaptive mountain bike.

I was learning a lot very quickly. Fusion was aiding me in this. And, as I developed my designs, I became more capable of helping my students with more complex solutions or problems at NYU Shanghai. I was getting better at Fusion 360, and my students were benefiting from that experience.

Giving the new bike a name seemed to solidify the direction. There's something about a name that makes it feel more real. I call the project, Project Mjolnir, and there were a few core tenets I wanted to stick to in its development. It was to be customizable. It was to be affordable. It was to be repairable. And it had to be evolutionary-- always able to change.

It also had to be possible to build it anywhere. I built the first one in the back of my kitchen utilizing a space not larger than six by nine feet to assemble it from my wheelchair. It started with basic construction of PVC pipe and foam core to establish space envelope for parts. Evolving through the stages of construction as and when parts arrived, the bike began to take form in this same space.

On completion of this build in January of this year, I was tentatively optimistic about the result. There it was. It existed. And more importantly, it was moving out of the kitchen as my significant other half, who's a purple belt in jiu jitsu, was becoming less and less patient with my obsession. But would everything I had done in Fusion 360, everything I assumed based on prior experience, work? Optimistic and a bit scared, it was time to find out.

After a little over seven months from the crash that caused the carbon park to disintegrate to the build of this bike, it seemed like a miracle that it existed. The first test of the bike went unusually well, considering the amount of issues I had assumed and anticipated.

I had also assumed a lot of positive things, many of them worked out. It wasn't completely flawless, but it was surprising how well it went. I think a lot was learned from all the previous failures. I think it's a trait of designers to constantly doubt our capabilities. And it was showing up in force for me with this bike.

However, I shouldn't have worried so much. It was a great feeling to test this bike and put ever more trust in the machine and know it would survive. To know too, if there was a need to change a part, it was only ever a few hours in Fusion 360 and a couple of weeks away from being a reality. We'd achieved speed in more ways than one.

I traveled to New York to teach for the fall semester of 2022. While there, I spoke to a number of my colleagues about the project. And it was then I was introduced to Maria DiKun, who heads up the VIP program at NYU Tandon School of Engineering. She suggested we apply to the program for spring 2023.

VIP stands for vertically integrated projects. There are longer-term projects carried out at NYU, often multiyear and multidisciplinary, incorporating innovation research to help students get hands-on experience developing solutions to real-world problems. There are over 50 active projects in the program with thousand-plus students involved. It really is a great initiative with some great people driving it forward.

At this time, my constructor on the project, Phil Caridi and I, had applied and were successful in getting into the program. We quickly got to work reaching out to contacts to see if we could get some support for our ambitious plan. We were going to build four bikes in four locations around the world within the first year. The objective being that we would prove that we could build a bike quickly and easily anywhere, that could be repaired, upgraded, developed on site when needed or desired.

We were incredibly fortunate to get the support of Specialized Bicycles and SRAM bicycle components, who provided us with help by way of parts for those bikes. We also got ourselves a bit of graphic design love and had our logo made. It's inspired by the Halo video games, in which the Master Chief, the main protagonist, wears the super armor of the same name, Mjolnir. It's also the name of Thor's hammer. We see that instrument as a means to breaking down barriers.

The concept for Mjolnir is as follows, a modular platform that allows you to build any one of four variants. The frame can be upgraded when the customer requires and can be repaired quickly if you do manage to break a part. It utilizes standard off-the-shelf bicycle components for its running gear, most of which is available at any bike shop or online bike store.

The entire structure is based around 250-millimeter diameter pipes and utilizes standard-length fasteners to bolt together. There are no welds required to create the frame. If a frame component gets damaged, it's easily replaced, minimizing downtime of the bike.

If a person wants to upgrade to a suspension module, it's as simple as removing one substructure and attaching another. The frame also has adjustability for sizing, and simply cutting the pipes down can decrease the overall size of the bike.

For the next three months, Project Mjolnir team worked remotely, utilizing Fusion 360 to develop the new parts that will form the simplified affordable bike. Meeting weekly and in contact daily, the design quickly evolved.

On a tight schedule to design the bike and then have the parts made, we executed on this phase in nine weeks. This left us with three weeks for parts to be made and shipped from China. We could not afford any large errors. In preparation for the assembly, we were fortunate to receive support from Shawn van Every at ITP NYU Brooklyn in finding space to build the bike.

In April of this year, having never sat in the same room, the team comprising Phil Caridi, Guglielmo Donda, several other staff and students, and myself, began assembling the first bike with no idea if it would come together.

Over the next three days, we worked tirelessly. We had some hiccups around fasteners and some issues on part fit tolerance, which we were largely able to solve on-site capability and help from workshop manager Luke [? Bowen. ?] Every issue was recorded and amended in the Fusion 360 file and ready to be sent to our manufacturing partner before the next manufacture cycle.

On April 24 of this year, we took the first adaptive mountain bike in New York City across the Brooklyn Bridge on its first ride. It was the first adaptive mountain bike to be ridden on trails in New York City not long after that.

Fusion was always our common language during that three days. There was always a laptop or iPad open with the CAD file ready to view. We constantly referred back to the model in the software when figuring out what goes where. It acted like the ultimate instruction manual for us to assemble the bike. It also allowed us to make those all-important amendments to ensure the next build went more smoothly.

Phil Caridi and Guglielmo Donda assembling Mjolnir, Luke [? Bowen ?] was also instrumental in its success. It was a crazy few days at NYU in Brooklyn. In July, the first bike took to the trails of Freshkills Park on Staten Island, piloted by Rachel, seen in this picture.

Under the guidance of Matt Lebow and the New York City Mountain Bike Association, this was the first time Rachael had ridden a bike in 15 years. It's incredible to believe that we only embarked on the design journey earlier in the year. We have another ride planned for this year where we hope more people with disabilities can experience the thrills of adaptive mountain biking in New York City.

Of course, there were tweaks to be made. And this was carried out with Laura Shengying, who has been aiding our parts development and manufacture in China. We spent some time implementing the changes we needed from the first build into the manufacturing BOM and sent those for manufacture. It wasn't long before we were building bike number two.

The second bike was assembled in Abu Dhabi at the NYU campus there. We aimed to begin the build in mid-June. In order to get a clearer idea of the facilities required for the build, we were able to discuss the design, the phases of the build, and the space required for that build at New York Abu Dhabi. We also reached out to the Abu Dhabi cycling club and a trail at exit Hudayriat Island where we could test the bike. With prior knowledge of the first build, this bike was assembled in less than two days.

Again, Fusion played its role. Before I arrived in Abu Dhabi and before the parts arrived in Abu Dhabi, students could access the files and understand what they were going to be working on. Under the guidance of Jorge Montalvo and Ted Lee, we got this bike done faster.

The project was now becoming global. Two bikes at two locations in three months, one in New York City and one in Abu Dhabi. We had proven that we could build a bike in multiple locations. It was only two locations, but it was still multiple.

We also made another little bit of history by writing the first adaptive mountain bike in the UAE on trails in the UAE. Scott Carney, co-director of athletics at New York University Abu Dhabi, working with Wolfie's Bike shop at Hudayriat Island ensured we could achieve this. It was a test of real-world conditions and a lot of fun into the bargain. We also did a 40-kilometer night race that same day, which really tested the bike build and my own endurance. Bike two still had some tweaks, but it was running well.

The bike in Abu Dhabi was also ridden by Ahmed, pictured here. Ahmed will be trying the bike again this fall as we develop it at Abu Dhabi campus. We're also utilizing Project Mjolnir in Abu Dhabi to teach students design. They will reverse-engineer and try to improve component design as part of their studies.

The project itself is a beacon of inclusivity in NYU's diversity and inclusion efforts, and we look forward to building more bikes in Abu Dhabi, where an extensive cycling network has been developed as part of Abu Dhabi being a UCI designated cycling city.

The third bike was built in Ireland, and it is an iteration of the original design. The design incorporates more parts being made by laser cutting in an effort to cut down costs further at the manufacturing stage. This evolution of the frame will be cheaper and easier to manufacture and will be the basis of the design files released on open source. This bike will be used by wheelchair-users on trails in Ireland, offering them the opportunity to experience the thrill of mountain biking.

The fourth bike will be built in Shanghai, and will be the first adaptive mountain bike in China. We look forward to trialing it at trails later this year or early in 2024. All four bikes will see further development this fall semester and in early 2024 as we continue to develop the platform and add features to those bikes.

So far, we have achieved the objective we set out to achieve. With Fusion 360, we will continue to develop the platform and create the modules that enable the upgradability of the four examples we are building. We will be releasing the design files to the public for those wanting to build a bike for private use. We hope to build a community of riders, builders, and innovators as well as continue to develop the platform as an educational experience learning about design and manufacture.

So what's next for Project Mjolnir? The frameset has already evolved, and we're going to release those files. We're also developing the suspension modules and other elements of the bike ourselves that will serve to make the bike better. We hope the community will add to that value by utilizing the files to build on what we have done so far and contribute to Mjolnir's development.

We will also continue to seek industry partners and support to develop the bikes further in education. I myself would like to see these bikes everywhere you see a city bike. Maybe this can be another kind of micromobility platform.

We will continue to utilize NYU's world-class prototyping capabilities at LaGuardia Studios and Tandon in New York City. There are incredible resources, such as 3D metal printing, which will aid in construction of functional structural parts, not achievable by regular manufacturing techniques. It opens up the possibilities of bespoke control interfaces for Mjolnir for specific needs of individuals. We can explore how we can help people with varying abilities as a result.

Machining and manufacturing capabilities at New York University Abu Dhabi will help us further refine the frame design and design and test multiple variants. Having on-site capability further reduces lead times to a part design and, more importantly, an answer to a question. Further design and development at New York, Shanghai-- at New York University Shanghai will help to educate students while advancing Mjolnir also.

Being able to design, and develop, and deploy a project on a global scale will give students at NYU an insight in how to manage a project like this, a truly global project, at the global university network.

This project encompasses so many things. It's about education. It's about evolution. And, most importantly, it's about inclusion. It's about taking something that was out of reach and making it accessible to more people. It is the pursuit of knowledge in doing this, and the development of empathy while doing this, that will help students at NYU design and build for people in the future.

We believe that a bike can be built by an individual for much less than the cost of what's on the market currently and upgrade it as and when they need to do so, giving more people with disabilities the chance to participate in the sport.

We think some of the next steps are in generative design and how we can optimize further and explore other ways to make parts. How can we optimize material use? How can we make a part more efficient? How can we make parts customizable to the individual's needs?

All this work moves us towards a more accessible future. While I've spent the last 25 to 30 minutes talking about an adaptive bike, this bike may well be a platform that spawns innovations we didn't realize we need in the future. Would anyone like to guess what these products have in common?

Did you know that all the products on this image started life as something to help a person with a disability? The keyboard was created to help someone who was losing their vision to communicate. The electric toothbrush was developed to help people with dexterity issues to be able to brush their teeth. The audiobook, or Audible, as we might know it today, began life as the Talking Book so those with visual impairments could listen to books.

Maybe Mjolnir will inspire students to come up with innovations we didn't realize we need. And just like when the keyboard, audiobooks, and the electric toothbrush were first invented, maybe those innovations won't be immediately widespread but will be ubiquitous in the future.

For me, personally, it's to try and provide the feeling of flying, the feeling of the sense of speed and excitement, to be totally immersed and absolutely focused on this exhilarating experience, to get back onto the trails, to help others to get back onto the trails, to go somewhere for the first time, to go somewhere where it was impossible to go before, to get back into nature, and have those adventures, to help physical and mental well-being in those with disabilities.

When Rachel and Ahmed could get back on a bike, it was, to them, a great day, something that when you can utilize a regular bike, it's easy to take for granted. We hope that this project can move us another stretch towards more people with disabilities having great days and close the gap in being able to do so more frequently. Project Mjolnir is as much as it is an educational platform as a means to promote freedom and independence. Thank you.