Frame building course: Build your own bicycle frame in 5 days
Text: Juliane Schumacher
Are you still looking or already on the road? If you cycle a lot and have already owned several bikes, you probably know the challenge of finding the perfect frame. When buying, compromises are often made in terms of equipment, geometry and price, and the first long tours can be painful. I (see also radmaedchen.de) can also tell you a thing or two about it. How great it would be to have a bike that is made exactly according to my ideas and measurements!
Option number one: Commission a frame builder with my dream bike.
Option number two: I decided to build the frame myself and took the opportunity to take part in a frame building course in a fully equipped workshop. Robert Piontek, the founder of Big-Forest-Frame-works, invited me to this exciting experience. The week in cold January was an exciting challenge for me.
Preparations for the bicycle frame building course
Before I visited the Potsdam workshop, I had to think about which bike I wanted. Should the frame be lugged or lugless? And should it be a road bike, gravel bike, MTB or trekking bike? The choice of bike type was quite free and was only limited by the time available. Robert Piontek helped me in advance by sending me a catalogue of questions by e-mail that I could use as a guide. Based on a previous bike fitting or a well-fitting bike, Robert designed the first frame with the help of a special bike software called BikeCAD.
At Big Forest, there is no standard geometry for bikes, as each bike should be customised to the rider. Although I initially considered a hardtail MTB, I ultimately decided to build a gravel bike with extra tyre clearance, also known as monster gravel. It's important to consider the other components at this stage, even if you're not assembling the bike yourself. Although it is not necessary to have a complete list of parts at this stage, bear in mind that factors such as tyre clearance, bottom bracket type, gearing and desired fork can influence frame planning. The details are then finalised on site in the workshop.
The following are just some of the things you will learn on the five-day frame building course at Big Forest Frameworks:
- (Flame) soldering
- Filing and grinding steel
- Cutting and drilling steel pipes
- Make design decisions (eyelets, pulls ...)
- Understanding the construction of a steel frame
- Defining the geometry and appearance of the frame
Day 1 of the frame building course
Is it possible to build a bicycle frame in just five days? At first I had my doubts, as I had hardly any previous knowledge when I entered the workshop on Monday morning. But these doubts turned out to be unfounded, as Robert and Konrad are experienced professionals and have already successfully guided many people on their way to building their own steel frames. The aim is always to carry out every job on the frame themselves.
At the three fully equipped workbenches with 3D-printed tool holders, up to three people can work on their bike frames at the same time. I completed the course together with podcaster Johanna Jahnke ("Die Wundersame Fahrradwelt") and her husband Timo (Benu Bags). Working in good company is simply more fun. The workshop offers a variety of small and large machines and devices to explore. It is interesting to find out what each one is needed for and whether you will use everything for your own frame building. Everything is clearly organised and easily accessible - from the floor drill to the frame jig and various cutting attachments. It feels like a bit of an adventure!
Frame building course Day 1: Preparation and familiarisation
The first day at Big Forest Frameworks was all about familiarising ourselves with the workshop and getting ready. We also started marking, cutting, drilling and filing tubes on Monday after a short introduction. At each workstation there was a long wooden box with a name on it containing the main tubes for the bike frame. It took a whole week and required several steps, tools and expertise to turn the steel tubes in the box into a complete frame.
In the frame building course at Big Forest Frameworks, the fillet-brazed method is used to make a frame from steel (either chromoly - an alloy of chromium and molybdenum - or stainless steel from Columbus or Reynolds). The choice of steel tubes and their diameters depends on the size, weight and type of bike. All selected tubes are butted, which means that the wall thicknesses within the tubes are different, even though they have the same outer diameter. In order to be able to cut them precisely, the material was first measured.
Tasks of the first day summarised
- Angle cutting
- Initial cutting, drilling and filing work on the pipes, including angle cutting
- Measure and mark pipe set
- Discussion of details such as the number of eyelets and pulls (inside/outside)
- Adjustment of the geometry in BikeCAD by Robert
- General bike fitting on the fitting bike based on the measurements sent in advance
Drilling on the second day of the frame construction course
On Tuesday morning, the day began at eight o'clock in the Potsdam workshop. After spending the first day mainly on preparations, cutting tubes and filing, the second day involved a variety of new tasks. In particular, many holes were drilled - depending on how many bottle holders and eyelets we wanted to use in total. But water outlet holes were also part of the plan. I alone had to prepare ten holes on the main tubes (top tube, down tube and seat tube) and was even allowed to try out the test soldering.
The standing drill was a great help at work! The thinner and more moulded the pipe was, the more challenging the drilling became. It required a lot of concentration and precision to ensure that the pipe was not accidentally drilled through. This step was followed by filing and deburring.
Highlight: Soldering for the first time
On Tuesday, we had the opportunity to work with fire. It was interesting to see how different working with the torch was compared to the noisy drill. Robert showed us how to carry out soldering on a test pipe and then we were allowed to try it out ourselves. First we ground the spot on the steel and applied flux. Then we lit the torch (gas-oxygen) and heated the tube with the thicker wall thickness at the connection points. We then slowly injected the soldering material (silver solder).
Incidentally, silver solder is often used because it works at lower temperatures and therefore 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 tried to break the soldered joint. It took some force and movement before it gave way. The purpose of the test is to find out how the pipes are joined together by soldering (see glossary below). On the same day, the flame soldering iron was used for the first time on the final steel pipes. After the holes had already been pre-drilled, the first eyelets were now firmly connected to the top and down tubes.
Tasks of the second day summarised
- Design decision: eyelets and type of cable/tension routing (inside/outside, with tubes or inserts)
- Drill holes for eyelets and cables
- Filing/deburring the interfaces on the pipes
- Cutting and adjusting the transitions from the down tube and seat tube to the bottom bracket
- Soldering eyelets with silver solder
Drilling and filing on the third day of the frame building course
On the third day, the focus was on precise filing and sanding. Drilling also played an important role and became increasingly challenging, as the rear triangle and chainstays are relatively narrow, sometimes flat and of different widths. Positioning the drill is therefore more difficult than with a uniformly shaped tube.
Soldering was also on the programme again
Lightweight tubes were used on the inner cables of my frame to allow the cable routing. To insert these tubes, I had to drill with a hand drill and be careful when doing so. Konrad showed me how to do it and then I dared to use the machine. Together we pulled the tubes through the holes in the steel pipe. In contrast to soldering, which I was very enthusiastic about, drilling was not so easy for me. It was reassuring to know that there was always someone nearby who could help me with any difficulties. I didn't know exactly how many drillings were still to come, but one thing was certain: there was still plenty of opportunity to practise!
On Wednesday, not only filing and drilling were on the agenda, but also soldering the dropouts. We all made progress with soldering. Over the course of the week, we learnt when and how much heat and silver is needed. The highlight of the day was definitely the first assembly of the main tubes (top tube, seat tube and down tube) with the bottom bracket and head tube in the frame jig. We checked the transitions and filed them down if necessary. The frame was slowly but surely taking shape. At this point, we almost thought that we would soon have made it. But there was still a long way to go - with filing, sanding, drilling and soldering.
These were the tasks of day 3
- Solder dropouts
- Cutting the rear end
- Drill holes for cables
- Bending and positioning tubes for trains
- Clamp the pipes in the frame gauge and check the transitions
- File
This was the fourth day of the frame building course
On the fourth day, everything already felt familiar. The morning began with small talk and a cup of coffee in the workshop, followed by a look at the previous day's progress. The anticipation for the day ahead was palpable. It was hard to believe that this was already the penultimate day of the frame building course. The past few days had been so intense and full of new impressions that it seemed hard to imagine that the course would soon be over.
On Thursday, the final work was carried out on the exits for the trains. Sawing and filing were carried out to create a finished frame from the individual tubes in the box that were given to the course participants on Monday. Although many small steps were still required to achieve the goal, Robert and Konrad coordinated these tasks so skilfully that all participants worked on the frame at the same time and sometimes at different times throughout the day.
Soldering the frame together
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 had made it a little easier to get down to the main work: assembling the pipes. Timo was the first to complete this step and received admiring glances. This made the rest of us want to take our turn and give our own frame a solid shape! I was the next to take on this task. The principle was simple: you worked your way around the frame piece by piece.
The first step was to tack weld by soldering the joints at certain points. This prevented the pipes from slipping and created an initial connection. The soldering material that had already been applied was then distributed around the joint by further heating. More soldering material was also used to create a stable connection. A lot of silver solder was used and the concentration was high. This work was exhausting, but also very satisfying! At the end of the fourth day, every participant had an (almost) finished frame in their hands.
Tasks of the fourth day
- Assemble tubes in the frame gauge
- Tacking pipes
- Shaping and shortening struts
- Filing the rear drawbar outlets
- Solder tubes together = frame is created
The last day of the frame building course
How quickly can a week go by? The last day at Big Forest Frameworks was approaching - at least in theory. Although everyone managed to finish the frame, it still needed a little fine-tuning at the end - in the truest sense of the word. The soldered joints had to be worked on with files, a Dremel and sandpaper to achieve nice transitions at the joints of the tubes. Depending on how precise and detailed you want it to be, this can take more time.
Basically, I made good progress with the course, although I had to spend a lot of time on content production, such as taking photos and filming. Nevertheless, I still need at least one more day to finalise the work on the frame. Before that could happen, however, there were a few other tasks to complete on Friday. My frame still needed the seat stays and a 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 intensive week on the frame building course, each participant was allowed to solder the small Big Forest Frameworks logo tree to a desired position on the frame. For those who wanted to personalise their bike frame even more, there was the option of choosing an individual serial number with up to nine digits, which could also be applied by flame soldering. And with that, the five intensive days in the Big Forest Frameworks workshop were over. My finished frame: A monster gravel bike made from high-quality Columbus steel tubes.
This was on the agenda for the last day
- Saw and file the seat tube hole and slot
- Milling the bottom bracket, seat tube and head tube
- Soldering bridges and struts
- Cutting and drilling struts
- If necessary, set serial number and solder (Doro or Devin?)
- 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
- Ready for 1-fold and 2-fold switching
- Tyre clearance up to 50 mm (700C)
- Filing and grinding
- Soldering the Big Forest emblem
Conclusion
Evaluation of the framework course
In the five days I spent in the Potsdam workshop, I definitely learnt that you can build a customised bike frame in a well-equipped workshop without any previous knowledge and with precise instructions. The course is very practice-orientated and starts directly with a short introduction and safety instructions. Then it's straight onto the materials. The most important prerequisites for taking part in a frame building course are motivation, the ability to listen and observe and the desire to get stuck in and get things done!
In their course, Robert and Konrad impart specialised knowledge that enables participants to build their own bike frame on site. However, it is advisable to have a basic understanding of the parts that make up a bicycle. You shouldn't be afraid to get to grips with fire and a drill. If you fully commit to the course, you can have a fantastic time in the workshop. The time flies by during the concentrated work and in the end you have a customised frame that may not be perfect, but is definitely unique!
Frame building course suitable for everyone?
This is an ideal course for anyone who is curious to better understand their favourite means of transport and wants to express their creativity. This course is particularly suitable for people who find it difficult to find a suitable bike on the market due to their size (very large or very small) or special needs. At the end of the course, participants can not only proudly take their self-built bicycle frame home with them, but they will also be rewarded with new knowledge, numerous impressions and valuable experiences. This week will be an unforgettable experience! And who says it has to be a one-off experience?
Who founded Big Forest Frameworks and why?
Robert Piontek, the founder of Big Forest Frameworks, found his way to frame building via an unconventional path. Originally born and raised near Detroit, USA, he developed a passion for craftsmanship at an early age by working on cars in his father's garage. Although he initially earned a doctorate in astrophysics and worked in science, Robert eventually moved to Germany. After a brief stay in Hamburg, he settled in the tranquil town of Babelsberg near Berlin.
Not entirely happy with his career choice, he decided to take a brief foray into the world of wedding photography before discovering his passion for frame building during a visit home. In 2012, he founded Big Forest Frameworks and today his company is one of the leading providers of frame building courses in Europe. Konrad Lenz joined the American company in 2022, bringing with him his many years of experience in the bicycle industry.
Cost of the frame building course at Big Forest Frameworks
In spring 2024, the price for a five-day frame construction course without sleeves was 2350 euros. In addition, material costs are incurred, which amount to an average of approx. 600 euros for steel and approx. 1400 euros for stainless steel.
Glossary
- Flux: The flux has the function of keeping the steel clean during soldering. This allows the soldering material to adhere better to the material (steel) and spread evenly. In the course, we use silver solder, most of which is coated with an additional flux.
- Fillet Brazed: The frame is joined by soldering with brass or silver. The tubes are joined together seamlessly and the transitions are carefully sanded and filed. The result is a finished frame that looks like it is made from a single piece, with smooth transitions between the tubes. This construction method enables a wide variety of bicycle types and allows flexible design options in terms of geometry and angles.
- Lugged Brazed: The frame is held together with the help of sockets. This gives it a classic look and makes it possible to achieve an elaborate and elegant effect with differently designed sockets. Basically, this construction method is simpler, but there are certain restrictions regarding the angles and geometry of the frame due to the prefabricated sockets. This results in additional material costs.
- Soldering: Welding and soldering are two different techniques for building a frame and joining pipes together. There are some differences between them, such as the temperatures used, the type of joint and the durability. At Big Forest, silver solder (a metal alloy) and a torch (gas-air mixture) are used to flame solder. This means that additional brazing material 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 are not connected directly to each other, but the brazing material is connected to the steel. If temperatures above 450 to 1000 degrees Celsius are used, this is called brazing; if lower temperatures are used, it is called soft soldering.
- Welding: In the mass production of bicycle frames, these are usually joined by welding. In this process, the tubes are fused together at high temperatures of over 1000 degrees Celsius either by heat and/or pressure (sometimes with additional material). The resulting weld seams can vary in size and thickness depending on the technique used and are often not completely smoothed in mass production. This method requires more effort, carries the risk of damaging the material due to the high temperatures and requires additional equipment.
