Frame building course: Build your own bike frame in 5 days
Text: Juliane Schumacher
Are you still looking or are you already riding? Anyone who travels a lot by bike and has already owned more than one bike will probably be familiar with the difficulty of finding the perfect (suitable) frame. Compromises are often made when buying in terms of equipment, geometry and price, and it is not uncommon for the first long tours to be painful. I (see also radmaedchen.de) can also tell you a thing or two about this. How nice it would be to have a bike that is made entirely according to your own ideas and measurements!
One possible solution: Order the bike from a frame builder.
The second option: Building the frame myself, for example under the guidance of a frame building course in a fully equipped workshop. That's exactly what I did at the invitation of Big Forest Frame Works founder Robert Piontek during a cold winter week in January.
Five days frame building course - the preparations
Before I went to the Potsdam workshop, I had to think about my dream bike. Should the frame be lugged brazed or manufactured without lugs? Road bike or gravel bike, MTB or trekking bike? The choice of bike type is relatively free and basically only limited by the time frame available. Robert Piontek already takes you by the hand here and sends you a catalogue of questions in advance by e-mail, which you can use as a guide. On the basis of a bike fitting or a well-fitting bike, Robert produces the first frame design using special bike software (BikeCAD).
There is no standard geometry at Big Forest, because the bike should ultimately always suit the person riding it. After initially opting for a hardtail MTB, I ended up choosing to build a gravel bike with extra tyre clearance, aka monster gravel. At this point, it makes sense to get to grips with the other components, even if you don't build the bike yourself later on. Even if it is not necessary to already have a complete parts list, you should be aware that tyre clearance, bottom bracket type, gearing and the desired fork, among other things, can influence the frame planning. The details are finalised on site in the workshop.
What you learn in a five-day frame building course at Big Forest Frameworks, among other things:
- Defining the geometry and appearance of the frame
- Understanding the construction of a steel frame
- Make design decisions (eyelets, pulls ...)
- Cutting and drilling steel pipes
- Filing and grinding steel
- (Flame) soldering
Frame building course day 1: Get to work on the steel tubes
Can you build a bicycle frame in five days? I had my doubts at first, as I didn't have much prior knowledge when I entered the workshop on Monday morning. But my doubts were more than unfounded, because Robert and Konrad are professionals and have already accompanied many people on their way to building their own steel frames without any pressure or prejudice. The aim is always to realise every piece of work on the frame themselves.
Up to three people can work on their frames at the same time at three fully equipped workbenches with 3D-printed tool holders. That's a good thing, because I completed the course at the same time as podcaster Johanna Jahnke ("Die Wundersame Fahrradwelt") and her husband Timo (Benu Bags). It's much more relaxed working in good company. Numerous small and large machines and devices make exploring the workshop a little adventure. What do you need for what? Will you use everything for your own frame construction? The drill bit here, the frame jig there, various cutting attachments - everything is well organised and within easy reach.
Getting to know and preparing
The first day at Big Forest Frameworks was like a discovery tour and was entirely dedicated to familiarising ourselves with the workshop and the preparations. After a short introduction on Monday, pipes were marked, cut, drilled and filed. Each workstation had a long wooden box labelled with a name. Inside: the main tubes required for the respective bicycle frame. Over the course of the week, it took several steps, tools and expertise to turn the steel tubes in the box into a complete frame.
At Big Forest Frameworks, a frame is built from steel (chromoly = chrome-molybdenum steel or stainless steel from Columbus or Reynolds) using the so-called fillet-brazed method (see glossary below). The choice of steel tubes and their diameter depends on the size, weight and type of bike. The selected tubes were all butted, i.e. the wall thicknesses within the tubes are different for the same outer diameter. In order to be able to cut them accurately, the material was first measured.
The following was also on the programme for the first day
- General bike fitting on the fitting bike based on the measurements sent in advance
- Adjustment of the geometry in BikeCAD by Robert
- Discussion of details such as the number of eyelets and pulls (inside/outside)
- Measure and mark pipe set
- Initial cutting, drilling and filing work on the pipes, including angle cutting
Frame building course day 2: Drilling begins
It was eight o'clock in the morning on Tuesday when we set off for the Potsdam workshop. After the first day was all about preparation, pipe cutting and filing, day two offered a variety of new tasks. Above all, holes were drilled, lots of holes! Depending on how many bottle holders and eyelets you had generally decided on, the more often the drill had to be used. But water outlet holes were also planned. I had to prepare ten holes on the main tubes alone (top tube, down tube and seat tube), but I was also allowed to do some trial soldering.
How good that the drill bit made the work a little easier! The narrower and more moulded the pipe was, the more difficult the drilling became, and it requires a lot of concentration and precision to avoid drilling completely through the pipe, for example. This step was followed by filing and deburring.
A highlight of the frame construction course
We were already working with fire on Tuesday. What a contrast the finer work with the torch offered compared to the somewhat brutal work with the loud drill! Robert showed all the participants how soldering works using a test pipe, and then they were allowed to try it out for themselves. Firstly, the area on the steel was ground and a flux applied. Then the burner (gas-oxygen) was lit, the soldering material (silver solder) was taken in the hand and the tube with the thicker wall thickness was heated first at the connection points. The soldering material was then slowly poured in.
Incidentally, silver solder is often used because you can work at lower temperatures as it lowers the working temperature of the solder. It flows better than brass, but is also more expensive. After the test soldering, all the course participants got their hands dirty and tried to break the solder joint. It took some force and jolting before it gave way. The purpose of the test is to recognise how the pipes are joined together by soldering (see glossary below). On the same day, the flame soldering iron was allowed to work on the final steel pipes for the first time. After the holes had already been pre-drilled, the first eyelets were now firmly joined to the top and down tubes.
The tasks of the 2nd day
- Filing/deburring the interfaces on the pipes
- Cutting and adjusting the transitions from the down tube and seat tube to the bottom bracket
- Design decision: eyelets and type of cable/tension routing (inside/outside, with tubes or inserts)
- Drill holes for eyelets and cables
- Soldering eyelets with silver solder
Frame building course day 3: Filing, drilling, filing
The third day was dedicated to intensive filing and sanding. Drilling was also very important and became increasingly challenging, as the rear triangle and chainstays are relatively narrow, sometimes flat and of different widths. It is therefore much more difficult to set up the drill than with a uniformly shaped tube.
Filing, drilling, soldering
In the case of my frame, lightweight tubes were used to guide the internal cables. Drilling with a hand drill and some dexterity were required to insert the tubes, which look like large drinking straws. After Konrad had demonstrated the process once, I also dared to use the machine. Together we then pulled the tubes through the holes in the steel pipe. In contrast to soldering, which I was more than enthusiastic about, drilling was not as intuitive for me. It was a relief to always have someone nearby to support me in case of difficulties. I had no idea how many drillings would follow. But one thing was certain: I hadn't finished them all yet, and there were still plenty of opportunities to practise!
On Wednesday, however, not only filing and drilling were on the programme, but also soldering the dropouts. Everyone made clear progress in soldering. Over the course of the week, they gradually developed an understanding and feeling for how much heat was needed when and how much silver was needed where. The highlight of the day was certainly the first assembly of the main tubes (top tube, seat tube and down tube) with bottom bracket and head tube in the frame jig. The transitions were checked and filed again if necessary. The frame was clearly taking shape. At this point, you could almost have thought it was almost finished. But there was still a long way to go with filing, grinding, drilling and soldering.
Day 3 Included
- Cutting the rear end
- Drill holes for cables
- Bending and positioning tubes for trains
- File
- Solder dropouts
- Clamp the pipes in the frame gauge and check the transitions
Frame building course day 4: Making a frame
On the fourth day, everything already felt very familiar: the small talk in the morning and the first coffee immediately after arriving at the workshop, the first look at the previous day's progress and finally the curiosity about the day's events to come. It was hard to believe that this was already the penultimate day! The previous days had passed so quickly, immersed in the work and with so many new impressions, that the idea of being on the verge of completing the frame building course seemed very unreal.
The final work on the exits for the trains was carried out on Thursday. There was sawing and filing. The individual tubes in the box that had been given to the course participants on Monday had been turned into something that looked more and more like a finished frame. In reality, many small steps were still needed before it was really ready. Robert and Konrad coordinated these so skilfully that in some cases everyone was doing the same work on the frame at the same time, sometimes at different times throughout the day.
Soldering the frame together
In this way, they ensured that each person received the support they needed for the challenging tasks. At this point, the soldering was already going really well. The many small soldering tasks of the previous days ensured that they were now a little more confident about the main work: assembling the tubes. Timo was the first to complete this step, earning admiring glances and the desire to take his turn and give his own frame a solid shape! I was the next to tackle this. The principle was simple: you work your way round the frame piece by piece.
The first step was to tack weld. This means that the joints are first soldered at certain points to create an initial connection between the pipes and prevent them from slipping. The soldering material that has already been applied is then further distributed around the joint by heating it again. More solder is then injected to create a durable joint. A lot of silver solder was used and the concentration was high. It was really exhausting, but at the same time a lot of fun! The result was impressive, because at the end of the fourth day, everyone had an (almost) finished frame in their hands!
Day 4 in brief
- Filing the rear drawbar outlets
- Assemble tubes in the frame gauge
- Tacking pipes
- Shaping and shortening struts
- Solder tubes together = frame is created
Frame building course day 5: The first own frame is almost finished
How quickly can a week go by? The last day at Big Forest Frameworks was approaching - in theory. Because even though everyone managed to complete the frame, it still needed a bit of finishing touches at the end - in the truest sense of the word. The soldered joints still had to be worked on with files, Dremel and sandpaper in order to achieve beautiful transitions at the joints of the tubes. Depending on how precise and fine you want this to be, the more time you can spend on it.
Basically, I think I made it through the course very well, especially when you add in the time that was needed for content production, such as photography and filming. Still, at least one more day of grinding at home would be needed to finalise the work on the frame. Before this final step, however, there were a few other tasks to complete on Friday. My frame still needed the seat stays and the small bridge between the stays, which first had to be moulded and soldered on.
At this point, it was also necessary to check whether the wheel was centred in the rear triangle or whether it needed to be corrected. As a reward for this full week's frame building course, each person was then allowed to solder the small Big Forest Frameworks logo tree to a desired position on the frame. Those who wanted to personalise the bike frame even more could think of a maximum nine-digit serial number, set it and then also solder it on. That was it! Five intensive days in the frame building workshop at Big Forest Frameworks were over. My finished frame: a monster gravel bike made from Columbus steel tubes.
The last day summarised
- Cutting and drilling struts
- Soldering bridges and struts
- Saw and file seat tube hole and slot
- Milling the bottom bracket, seat tube and head tube
- Soldering the Big Forest emblem
- If necessary, set serial number and solder (Doro or Devin?)
- Filing and grinding
- customised to your own dimensions with suitable geometry
- Total number of eyelets: 11 (3 bottle cages and luggage rack mount)
- Completely internal cables possible for shift and light cables
- Tyre clearance up to 50 mm (700C)
- Ready for 1-fold and 2-fold switching
Conclusion on the frame building course
Frame building for everyone?
What I definitely learnt during the five days in the Potsdam workshop is that you can build a customised bicycle frame under precise guidance in a well-equipped workshop, even without any previous knowledge. The course is clearly practice-orientated. After a short introduction and a few safety instructions, you get straight to the materials. The most important prerequisites for taking part in a frame building course: motivation, the ability to listen and watch, as well as the desire to get stuck in and do it yourself!
Robert and Konrad impart the necessary knowledge so that every person who takes part in the course can build a bicycle frame independently on site. Nevertheless, you should be aware that it is helpful to have a basic understanding of the parts that make up a bicycle. You shouldn't be afraid of fire and you shouldn't be afraid of using a drill. If you really get involved in the course, you can have a very good time in the workshop. The time flies by with the sometimes very concentrated work and in the end you have the frame of your dreams, which is certainly not perfect but unique!
Who is the frame building course suitable for?
For anyone who wants to better understand the construction of their favourite means of transport and get creative. However, the course is particularly suitable for people who are unable to find a suitable bike on the broad bicycle market due to their dimensions (very large, very small, somewhat heavier, etc.) or personal characteristics. At the end of the course, the participants not only take home a frame that they have built themselves. They also take home new knowledge, countless impressions and experiences that make this week a unique experience. Although... who says it has to be just once?
FAQ: Who is behind Big Forest Frameworks?
Robert Piontek, founder of Big Forest Frameworks, came to frame building via a few detours. Born and raised near Detroit, USA, where he learnt to screw cars in his father's garage as a hobby, the craft has always been close to his heart. He initially completed a doctorate in astrophysics and worked in science. At some point, Robert ended up in Germany, and after a stopover in Hamburg, he moved to tranquil Babelsberg in Potsdam near Berlin.
Not entirely satisfied with his career choice, he took a detour into wedding photography before dedicating himself to frame building after a visit home. Big Forest Frameworks was founded in 2012. Today, Robert's company is one of the largest providers of frame building courses in Europe. Konrad Lenz has been supporting frame building since 2022. He brings many years of experience in the bicycle industry to the company.
How much does a frame building course at Big Forest Frameworks cost?
Currently, in spring 2024, a five-day frame construction course without sleeves costs 2350 euros plus material costs (steel on average approx. 600 euros, stainless steel approx. 1400 euros).
Glossary
- Flux: The flux keeps the steel clean during soldering, and the soldering material can wet the work material (steel) and flow better. Most of the silver solder used in the course is also coated with a flux.
- Fillet Brazed: The frame is soldered with brass/silver, i.e. the tubes are joined together with a solder seam. The transitions are ground and filed smooth so that the finished frame looks as if it were made from a single piece with flowing tube transitions. You can build any type of bike this way and are free to choose the geometry and angles.
- Lugged Brazed: The frame is held together by sockets. The look is classic and can look very elaborate and elegant thanks to the differently designed sockets. In principle, this variant is easier to build, but the finished sockets impose restrictions in terms of the angle and geometry of the frame. Additional material costs are incurred.
- Soldering: Welding and soldering are both techniques for building a frame and joining pipes together. They differ, among other things, in the temperatures used, the type of joint and the durability. At Big Forest, silver solder (metal alloy) and a torch (gas-air mixture) are used for flame soldering. This means that an additional soldering material is used, which is heated and applied to the material to join it together at the transitions. The tube is only heated so that the solder can flow better and bond with the steel. The steel tubes of the frame do not bond directly to each other, but the brazing material does bond to the steel. Temperatures above 450 to 1000 degrees Celsius are referred to as hard soldering, below that as soft soldering.
- Welding: In large frame production, the bicycle frames are usually welded, i.e. the tubes are joined together directly by heat and/or pressure (possibly with additional material) at temperatures above 1000 degrees Celsius. The usual weld seams (beads) vary in size and thickness depending on the technology and are often not smoothed out to any great extent in mass production. The technique is more complex to use, harbours a greater risk of damaging the material due to the high temperatures and requires more equipment.
