Why I build an irregular bike — Part #3

Kees Plattel
5 min readDec 30, 2016


So… with the last order of bike parts arriving, all the way from Melbourne, taking more then 2 months to get delivered, 2015 came to an end. And 2017 is one day away now…

With that in mind, I really wanted to 'finish' this thing and give it a spin. Which is something that I consider to be an achievement. I managed, and it has seen improvements since. This is the reason why this part III is delayed by 8 months. Below are several adjustments I’ve made on top of the original design:

  • While spoking my own wheels, trying to figure out how to mount things, I found these curtain rail brackets, that would perfectly hold brake & shift cables, so that would be neatly tucked away through the length of the frame.
  • As noted earlier, I was inspired by VanMoof’s lights, designed in 3D a plug for the bar ends of aluminium on my bike, with a little hole for an LED screw mount, download that file here in case you want to experiment with it. There were a few tube ends that also had to be closed in a neat way with as much space left as possible. A closing cap that can be printed from recycled plastic is in the download too!
VanMoof inspired lights.
  • The chain runs through the whole length of the body, and tension needs to be strong enough not to derail it from the sprocket. To counter this, I’ve drilled an extra hole in the cross bars of the steering frame, where I mounted a derailleur that pulls the chain in the right tension and let if flow neatly through the frame without hitting it. It’s especially close on cross bars and there’s no way you could do that without.
  • The steering bar itself was recommended to be aluminium. Saving little weight + space I’ve opted for a long threaded rod with two ended bearings on either end that hold perfectly in a bolt that is fixed both steering sides. This gives it a more clean look, as it’s more responsive with steering when one wheel is lower then the other due to the bearings being able to slightly turn and bend from the opposing side.
Bearing + threaded rod as steering column.
  • I highly recommend learning how to spoke wheels. It’s an interesting, frustrating experience that will make you respect the people that are passionate about bikes a lot more.
  • The mounts for the bottom bracket + rear axle were put under more pressure then I anticipated, bending parts in the first testrun. After designing custom made steel plates to fix this, and had them made, they have not given me any trouble. Download the files here.
Ordering custom lasercut steel for the bottom bracket + rear axle mount.
  • You’ve got two hands, but three wheels. How do you brake? The bike lacks mounting points for breaks, especially on the front side since they are mounted as ‘lefty’s’. A term for mountainbike forks that only mount the wheel on one side. After readying on forums, the right way to go was to source a unique breaking system on eBay, especially designed for people with a disability. I wanted disk breaks, but without hydraulic lines containing fluid. I ended up buying the mechanical disk brakes from SRAM and a custom made handgrip that pulls two brake lines simultaneously.
  • I’ve designed a custom CNC/Waterjet formed seat. That works better, gives you more steering angle & ventilation on the back, which with polycarbonate didn’t really do. Next to that, aluminium is similar in weight but has better strength. My polycarbonate seat broke after 6 months. You can download that file here.
Custom seat.

To be…

Continued. What I realised is that this open source bike has given me is the trust in myself to build something with my bare hands and tools instead of a keyboard and mouse. 2016 has been a journey for this bike.

That’s something I’d like to continue on in the future, and I’ve been thinking out loud about this too, it’ll involve two wheels and a bunch of batteries to give you an idea.

For now, what I would love for you to take out of this is that creating such a thing is empowering, but to live and tell the stories, show the scars (didn’t really get any) and tell about how it’ll be improved and build upon, which in my opinion is the greatest strength & power of open source. Hence, The links and points above are to be taken and improved along the road once more!

Feel free to shoot me an email or reach out on twitter if you plan on building one and have questions. I also welcome feedback and design improvements with open hands! ❤



Kees Plattel