Adrenalin is pumping through my veins. This must be how hunters must have felt in the Serengeti just before they fired a fatal arrow at a nagging warthog. I am fully focussed and block out everything: no thoughts, no distractions. My lips are pinched together under my breathing mask. There's no way I can afford to make a mistake now. Very slowly, I direct the poisonous green flame onto the metal. The fire hisses at 1000 degrees Celsius. I can feel the heat on my skin. I can hear the orange glow of the steel through the jet-black lenses of my glasses. Now it's time! Leo is standing a few centimetres away from me, watching my timing. I'd be lost without this man!
Pioneering work
Two hours earlier: Leo holds out his hand to me with a grin. He wears thin glasses. Long black hair falls over his shoulders. Thick woollen socks are tucked into his strappy leather sandals. A tiny pistol dangles from his left earlobe on a chain. The 39-year-old is a quiet, gentle but determined type. On his body: a boiler suit, his personal trademark. At the last Eurobike, his freaky look immediately caught my eye and I could hardly tear my gaze away from the delicate, colourful tubes of his exhibits. I quickly realised that I wanted to build a 32-inch bike in one of his frame building courses. There was still nothing available off the shelf for the new wheel size. However, this also meant that I had zero experience with suitable geometries and material requirements. Leo was one of the first to build a 32" chassis, but my customised frame was to be his first project with a suspension fork.
"I've got one here for you too," says Leo and hands me a second boiler suit. Although I haven't done anything yet, I already feel like the king of craftsmen. But first Leo pulls a simple bike fitting frame out of the corner. He wants to take another look at the geometry sketch from his CAD programme, which we had already agreed on in advance, on a living object. I climb into the saddle and immediately feel that it fits like a glove! Leo also seems satisfied, walks around me and murmurs: "This thing is going to be really big!"
Just like in grandpa's day
Next, Leo explains the radius grinder to me, a screeching beast that eats its way through steel with rotating sandpaper. Only now do I realise how complex it is to join two round pipes together. All connections need precisely fitting mitres. There is a maximum tolerance of half a millimetre. "No messing around" Leo increases the pressure. The tube set for my chassis is very thin-walled in places, sensitive and valuable. The down tube is the longest and most stable tube available from Reynolds in the UK. The top tube was specially commissioned by Leo from Columbus in Italy. The precisely machined bottom bracket shell comes from Hanover. The seat tube went to a specialist in Luxembourg, who bent it into shape so as not to get in the way of the large rear wheel.
We can determine the tube lengths and angles at the frame construction gauge using a digital protractor, ruler and caliper. Leo has got himself a new model from Cobra. "The Lamborghini of frame building gauges" smiles Leo and adds: "My old one was too short for your monster frame." Transferring the dimensions to the machines is a science in itself. I first have to develop a feel for the tools and am initially completely at a loss in the small workshop. Reamer, centre punch, scriber and Dremel: I had last heard these vocabulary words in my grandfather's garage. "Er, where does this thing come on?" I blurt out. Fortunately, Leo helps me. After his apprenticeship as a two-wheeler mechanic, the Freiburg native went travelling. This old craftsman tradition had almost died out among his colleagues, but Leo stuck with it and spent four and a half years travelling between the studios of various frame builders.
1200 degrees
Leo specialises in brazing steel frames. In contrast to welding, this requires less heat. However, "less" is relative in this case. The main joints of my frame are soldered with brass at 900 to 1200 degrees. This is much more beginner-friendly than welding and gives the frame more flexibility. Soldered frames are considered to be less susceptible to breakage but also less rigid than welded frames. Where stainless steel components are used, such as the dropouts, 700 to 900 degrees are sufficient to melt the softer silver solder. A mixture of oxygen and either acetylene or propane flows through the torch. Various fluxes are added to protect the steel from oxidation. These are highly toxic and the flame is blindingly bright, which is why Leo hands me a respirator and soldering goggles. He shows me how to set the right mixing ratio at the rotary knobs using my ear and a lot of dexterity. When I light the gas and the fire cuts through the concentrated silence with a loud roar, I am shocked to the core.
My first test object is the head tube. This is to have two reinforcement rings soldered onto it to cope better with the forces when biking. Leo shows me the technique for a soldering point: "First flame the thicker material nice and close until it glows. Always preheat the solder straight away. Then squeeze in more distance and material. Adjust the angle slightly, let the solder sink in and away". He lets the flame dance across the metal with smooth movements. I am fascinated and excited at the same time. The heat, the poison, the protective equipment: it all gives me the creeps.
Art made of steel
When Leo hands me the burner, I'm super nervous and highly focussed. "Yay, great heat management, a natural!" Leo says happily. I'm delighted that he's standing right next to me and guiding me through the process: "Here now, let's take the point. Let the centre melt properly and then give it another go." Leo is both a free spirit and a perfectionist. His creations are bike-turned-works of art with an almost exuberant attention to detail: a little heart here, perfectly rounded edges there and silhouettes to kneel on. Fine structures, hollow, light and graceful like the skeleton of a bird, are his speciality. So much sophistication takes time. Leo himself also needs five full days to transform the 30 large and small metal parts into a frame.
Once the head tube has cooled down, the flux can be washed off with boiling water. Leo shows me how to grind off the excess solder. As in any metalworking shop, the file is the most important tool and, like any moderately talented apprentice, I immediately file a few notches into the workpiece. To get them out again, I have to grind even more. I'm slowly getting the hang of it and file in a flow to Leo's Latin American music. It's a wonderful contrast to my office job in the media industry! Reach, digital transformation and influencer behaviour seem miles away to me right now. I'm making a statement about my love of mountain biking with my own hands. My mobile phone is blocked from the Swiss network and there's no Wi-Fi here at the workbench. Instead of screen time, it's a holiday for the brain: in the madness of the current world, it's a gift I'm giving myself. The sun shines into the workshop on the site of the former Thomy mustard factory in Basel, where the frame builder recently moved. It is located on the second level of an old garage, which Leo built himself. Downstairs, a Swiss artists' collective is at work. During our coffee break, we philosophise about the future of mountain bikes and the rebellion against the system.
Setbacks
The next day, the down tube gets a reinforcing casting set and is married to the head tube. Today Leo is not entirely satisfied with my soldering technique: "Oh man, point by point, it's burning everything here. If it doesn't pull in properly, it can be really dangerous!" My learning curve has peaks and troughs. Euphoria and stress alternate throughout the day. I find drilling holes in the frame particularly scary. Once again, I'm grateful that Leo offers one-to-one support in his courses.
In the late afternoon, a drama is brewing. The down tube has warped under the heat and won't budge even with gentle force. "Fuck!" curses Leo. "I think we'll have to do that again." Excuse me? I think I've misheard him: "Again? All that?" Panic rises inside me. "My perfectly polished pipe!" I start to moan. "I'm afraid so, otherwise I wouldn't be able to sleep well. I'll start very early tomorrow," Leo replies with a furrowed brow. It bothers him, I can see that in his face. Whenever he takes a step away from me, he apologises. Leo wants course participants to do as much as possible of the work on their frames themselves. It's part of the concept: it's the only way to create an unrivalled bond. This is the only way to turn the bicycle frame into a consistent extension of your own personality.
Bending and crimping
In the workshop, Leo had been on the accelerator since the early morning. Fortunately, he had ordered a second down tube as an exception. We are now working in parallel at the two workstations in order to finish on time. Soon the future chainstays will be in the vice. The 32-inch wheels pose space problems for the frame. The long steel rear triangle could twist under load. To create enough space for the rear tyre and the chainring, we have to bend and squeeze the stays. Leo made the special tools for this himself from wood and an old spoon. We repeatedly hang the rear wheel from his 32-inch "El Grandito" in the jig. When it is inserted into the soldered rear triangle for the first time, we give each other a big high-five. The tyre clearance is on point and the tubes look like part of a bike for the first time. I can already feel the binding.
Nevertheless, this part is far from finished. It still needs a fitted connecting bar for stiffening as well as a bottle cage mount and the internal cable guides. In the meantime, I have become more experienced, know how to deburr cuts and which tools are best suited to which jobs. The foreman also trusts me so much that he leaves me alone in the evening. I work late into the dark with an angle grinder and metal drill. That night I dream of filing down the brass seams.
Pride and honour
It takes us almost the first half of the fourth day to meticulously align the brake mount. My fingers are thick and rough, my shoulders ache from the unaccustomed amount of manual labour. When the heavily butted top tube is finally in the jig, Leo lets out a relaxed: "Wow, that's really good. Really a statement!" I can literally see a load off his mind. Thursday evenings are "workshop hangarounds" in a weekly changing studio of the Basel steel frame builders. I'm invited, after all, I'm now a frame builder too - an honour!
The crowning glory of the week is a real soldering marathon. Everything is inseparably fused together. I confidently put on my equipment, light the torch, nod to Leo and grab a brass rod. I know exactly what I have to do, trust our team, put the gun on and shoot. The warthog no longer scares me. It hisses, roasts, smoulders and glows. When the still-warm frame finally lies in front of us, I'm exhausted. At the same time, I feel a heavy sense of calm spreading through me. And there's something else: pride. This beautiful piece of metal is one of the first 32-inch frames in the world. Unique, handmade, by myself!
Conclusion
I will never forget this frame building course at Leovelo for the rest of my life. How could I? After all, I'm bringing home the best possible souvenir. Artistic, hand-built and individual: I already have a very special bond with my 32-inch customised steel frame. I also did half a metal construction apprenticeship - brilliant! - Jan Timmermann, BIKE editor
Curious to see what happens with the 32-inch frame? The paint job and the dream build with matching parts will follow. You'll find all the articles here on BIKE soon.
Jan Timmermann
Editor
