Tuesday, December 13, 2011

Shopping trip #1

Today we are tired and content after our first trip to get materials and tools.

In the morning we took measurements on the 3D-model. It added up like this:

ca. 24 meters of aluminum

ca. 100 bolts

ca. 100 nuts

After that Andreas went and borrowed a Nihola cargo bike from the local Irma supermarket. They lend out the bikes for free. You do however have to leave 500 dkk ($90) in security, which will be repaid when the bike is returned unharmed. It's a great deal offered by the local Agenda 21 office in collaboration with Irma.

Then we were off to Glostrup, about 10 km west of Copenhagen. It was nice to get some fresh air, although it was a cold and rainy day. See map of route here.

In Glostrup we passed Harald Nyborg to pick up some tools for the Bicycle Innovation Lab workshop. We got a small drill press, a cordless drill and a heap of drills and bits.

After that we visited the friendly guys at Metalcentret. There we bought 24 meters of 25x25x2 mm aluminum square extrusions, weighing around 12 kgs and costing a 1.162 dkk ($207).

We secured it to the bike with strips and headed home. If anyone wants to do the same, some rope would probably be a better idea. Also remember to tie the extrusions to the bike in a way that they do not scratch the frame. Also remember that Metalcentret accepts cash only.

Sunday, December 11, 2011

First steps

Last week the HubJohn took its first shaky steps into physical reality. It included a couple of stumbles.

Setbacks included Søren running into a tight dealine at work, forcing us to postpone our shopping trip to Metalcenteret. Secondly the nice man at SKF revealed that the bearings we'd hoped to use for the front hub steering mechanism cost 1300 dkk / $230 a piece, which is about what we hope to pay for the entire frame. In order to make any sense the hub must be both cheap and easy to build, so it was back to the drawing board. We are now considering both off-the-shelf car-components and a CNC cut bolt-together sandwich assembly with roller bearings. Concept sketches for the sandwich are shown below. Let's see what happens when these new ideas hit reality.

Since we were not able to get the aluminum for the full scale bike this week, I picked up some balsa wood at the local hobby shop, which Søren turned into a 1:100 scale model of the lower frame. Balsa is a very soft and bendy wood, but the model proved to be nice and rigid. This seems like a good sign of the strenght of the Czech Hegehog assembly method that we are using.

Czech Hegehog

Based on the N55 XYZ SPACEFRAME VEHICLES building system - www.n55.dk

On tuesday we'll be at it again:)

Tuesday, November 29, 2011

First day at the Lab

Last week we formalized things with Lasse Shelde, Manager at Bicycle Innovation Lab. From now on we'll be working on the project every Tuesday.

So, today was our first day at the Lab.
We spent the morning scrutinizing the 3D-model. Conclusion was that the overall frame seems solid and ready for a full scale test. The upper part of the frame, including the seat-post and the steering would probably work with a bit of adjustment, but we don't think it looks quite right yet.

Based on the N55 XYZ SPACEFRAME VEHICLES building system - www.n55.dk

Then there's the front hub. We have a basic concept which seems good. The details of how to actually build it are still pretty foggy, but we're optimistic.

Our current concept for a double axis in-hub steering mechanism with disc brake. We'll explain it properly in a future post.

As explained earlier we owe a lot to the 1921 Ner-a-car when it comes to the hub.

After poking at the model for a while, we got on our bikes and headed for the Lab, paying a visit to N55 on the way. One of the space frame bikes was parked outside. After having worked on the 3D-model for a while, it was nice and reassuring getting hands on with a similar bike.
The N55 workshop is always an interesting place to visit. These day, they are working on some pretty cool construction methods. We got some tips on where to buy materials, and continued to the Lab.


At the Lab we had a meeting with Lasse and did a bit of planning. Our plan for next week is basically to go shopping, so we can start building before christmas.

Tuesday, November 22, 2011


What we're doing is building D.I.Y. cargo bikes with hopefully no welding needed. This is based on the N55 XYZ SPACEFRAME VEHICLES building system - www.n55.dkWe've got several designs on the drawing board, but the first to be built will be the HubJohn. It's a two-wheel cargo bike with a bolt-together aluminum profile frame and center hub steering. Here's what we've got so far:

Based on the N55 XYZ SPACEFRAME VEHICLES building system - www.n55.dk
Based on the N55 XYZ SPACEFRAME VEHICLES building system - www.n55.dk
Based on the N55 XYZ SPACEFRAME VEHICLES building system - www.n55.dk
Based on the N55 XYZ SPACEFRAME VEHICLES building system - www.n55.dk

Credit where it's due
Here's our inspiration:

Constrution method: The N55 XYZ SPACEFRAME VEHICLES

N55 made the original aluminum XYZ SPACEFRAME VEHICLES and made their drawings open source. We've chosen to use this construction method because it's easy, and no welding is needed. We don't know how to weld yet, and we figure that lots of other people who might want a cargo bike don't either. Plus it provides the possibility to make instant changes and modifications. Other than that it's cheap, light and looks cool.


Bike type: The Long John and the Bullitt

There's a long history of two-wheel cargo bikes in Denmark. Traditionally they were for some reason called John. The main types were the Short John and the Long John.

The Long John formula has recently been updated by the guys at Larry vs. Harry in the form of the Bullitt. It is an absolutely amazing bike, but comes at a price. The cheapest version costs $2.500,- delivery not included.

The steering mechanism: Center Hub Steering

You might consider the frame design of a two-wheeled cargo bike a simple question of carrying a load between two points, just like a simple beam. The two supporting points are the front and rear hubs. In that respect the existing bikes are not structurally optimal. This is because the frame has to reach up above the front wheel at a pretty steep angle in order to grab the front fork.

Structurally we'd rather avoid sending the loads at play in the structure up through these angles, as they are awkwardly steep and require very strong joints. It is not ideal.

We'd like to just connect directly from the front to the rear hub. This could strengthen the structure, save weight and lower the center of gravity of the bike - making it more comfortable to ride and steer.

The thing is, you wouldn't be able to turn the front wheel, which would be a problem. The straight forward solution is to use the front fork, and end up with the situation shown above. There is however an alternative in the form of Center Hub Steering.

Apparently it hasn't been done on a bike before. Maybe it's been deemed too complicated, or maybe the standard front fork has always been chosen out of old habit. Whatever the reason, we'll give Hub Steering a go and see if we can make it simple enough to be viable. It'd be cool if we can pull it off.

Apart from the practical reasons, we're also doing it this way because we think it looks nice.

Based on the N55 XYZ SPACEFRAME VEHICLES building system - www.n55.dk

We're not exactly breaking new ground with this mechanism. It's been done successfully before as early as 1921 on the Ner-A-Car. Below is the 1925 model.

The following video gives a pretty good idea of how the steering works. The delight of the Dutch owner helps make it a good view:

You might say that we're being in-consequent by choosing Hub Steering, as it will probably make it more difficult to build the bike. You would of cause be right, but for us this is where much of the fun comes from, and if we succeed we might actually bring something new and useful to the world of cargo bikes.
If not, we already have designs for a regular front fork-version, which we plan to build as well.

The DIY spirit: Copenhagen Suborbitals
A lot of our inspiration for starting the project comes from Copenhagen Suborbitals. We don't know much about practical bike building, but we figure that if those guys can build a man-carrying space rocket using plate steel, pipes from the local hardware store and a hairdryer, we should be able to build a cargo bike.

Copenhagen Suborbitals doesn't have much to do with bikes, but here's their launch vehicle Sputnik with one of their rockets and a cargo bike.


We're doing this for several reasons:

- to have fun
- to contribute to the DIY spirit
- to learn how to build stuff
- to make cargo bikes less expensive (we want some ourselves)
- to spread cargo bikes around world. Bike mobility and transport is the future, especially in urban centers
- to share our experience
- to hopefully inspire others


We're building the bike at the Bicycle Innovation Lab. The Lab will also cover some of our expenses for materials and lend us their expertise. Thanks a lot to Lasse and the other Lab rats:)

The Bicycle Innovation Lab is a brand new project and we're among the first to make use of their facilities. Check out their wide variety of activities, including exhibitions, lectures, debates, workshops, film nights and bicycle library.


We're two friends sharing an apartment in Nørrebro, Copenhagen, Denmark. We're doing this as a spare time project.

We are:

Søren Schaumburg

I'm a master student in Urban Design derived from studies in landscape architecture and city planning as an undergrad. I have a special interest in the mix of design and ecology that affects the public realm as well as peoples mindset. The DIY and Open Source spirit inspires me, and I hope to do the same and contribute with this project. Furthermore I, as an avid biker, can attest, cycling isn't just a form of transportation.

I just spent a half year in San Francisco as an apprentice at Rebar Art & Design Studio, working on a wide range of different project from exhibitions to reachable and highly visionary bike infrastructure with Gary Fisher. Currently I'm working at the Danish City Plan Laboratory (Dansk Byplan Laboratorium) as a part time student employee lay-outing their news magazine.
Some urbanism studies from the university - here.
A San Francisco blog - Urban Interim.
Flickr page - here.

Photo: Mikkel Munch Mortensen

Andreas Hammershøj

I'm an architecture school dropout, with a keen interest in all things involving bicycles, especially physical and social infrastructure in city planning and urban design. I plan to apply for a Master in Sustainable Urban Design at Lund University.

I once worked as an intern at Gehl Architects, but now I divide my time between the Danish Architecture Center where I work as a guide, and the Danish Cyclist's Federation. At the Federation I work as an OpenStreetMap Community Manager, working to improve the map used in our route planner Cyclistic.dk.
I also occasionally blog at Copenhagenize.com and CopenhagenCycleChic.com.