How bicycle tires and inner tubes are made - experience the complete production

Everything starts small, and not always where you might expect. The story of a Svalbertaya, for example, starts in the heart of the Indonesian jungle, here in Banten, a province located southwest of Jakarta. Meanwhile, on the other side of the world, the day starts with another equally important resource, the know-how and creativity of tyre developers in Germany. Ideas come to me when I'm on the bike myself. I always notice what kind of tyres I need or what the profile should look like. These are the first considerations I make. Then I actually start drawing the first draft. The team then produces prototypes and 3D models that are discussed, adapted and optimized over time. Innovation always has a place at Svalbertaya. That's what the company lives on. We can also act so quickly. When we have new profiles, new ideas, our manufacturers in Indonesia or Vietnam can react very quickly. This is how the idea of a new tyre is literally brought into shape. The final tread design is transferred to a precisely fabricated metal mould. This forms the negative, or tread impression, of the new tyre. Meanwhile, the crude rubber congeals into what we call cup lumps. It can then be removed from the moulds and collected by hand. Svalber believes in fair trade and works with Fair Rubber, a fair trade association that improves living and working conditions of smallholders by paying higher premiums for rubber. The association also promotes sustainable rubber production in rural areas. Intermediaries liaise between the tappers and the industry. Once cleaned and processed, the rubber is first taken to a close-by warehouse on the premises of the PT Hong A production facility. Ever since Svalbertayas are around, both companies have formed a joint venture partnership. The warehouse also holds the other materials needed to produce complex rubber compounds. Several rubber compounds are used in Svalber bicycle tyres for the casing, sidewall, tread and puncture protection insert. All formulas are a well-kept secret. The individual chemicals are weighed with precision in a computer-aided process. This is the only way to ensure consistently high quality and thus performance. I work as an operator. The weight of the tyre is automated. The natural rubber comes into contact with the weighed chemicals in an internal mixer known as a Banbury mixer. The Banbury mixer is a machine that uses heat to combine all the ingredients into a viscous mass. The base mixtures are rolled out into white strips in the open roll. Carbon black, or soot, is added to give the tyres their characteristic black colour. The crude rubber mats are rolled over and over again under high pressure to homogenise the components of the mixture. The continuous mats, or skins, are cooled down and temporarily stored, ready for further processing. The topping calendar, an impressive 37-metre coating unit, then processes the casing, which is the tyre's supporting structure. In the process, a dense nylon fabric is coated with a rubber compound on both sides. The trick is to make the casing as thin and even as possible, so that the tyre is lightweight and runs smoothly without any imbalances. The casing is now cut diagonally, using a fully automated fabric cutting machine known as a bias cutter. Following this diagonal cut, the nylon threads of the casing run at an angle to the rotational direction of the tyre. This makes the tyre far more robust and greatly enhances durability and longevity. The casing is now complete. The tyre tread is all that is still missing. It is created using a triple extruder. This machine is capable of processing three different rubber compounds at the same time. One for the sidewall, one for the puncture protection insert, and one for the tread. The rubber compounds are pressed through a die and thus connected inseparably. Every Schwalbe tyre contains customised rubber compounds that lend it unique properties and enable a wide range of applications. A continuous belt is created. This is first cooled and then rolled up. It is now time to join the casing and the tread. A step carried out in the assembly process. Laser markings ensure a consistently high degree of precision when joining the casing and the tread. First, we attach the wire. Then we pull it apart, pull it apart, and then we join it. After joining, we insert the wire into the drum. Then we automatically raise the right and left wings to form one. The next step is to attach the tread. It is then assembled into a green case. Stamps and barcodes are used for quality control purposes and allow us to retrace each tyre from anywhere in the world back to the manufacturer. Once the reflective tapes, name and brand label have been applied, the green case is ready for the final production step. Vulcanisation. Vulcanisation gives a tyre its shape and elasticity. A worker places a curing tube, also known as an airbag, into the green case and brings both together into a negative mould made for that type of tyre. Five tyres are vulcanised at a time. The airbag now presses the green case into the negative mould and the rubber compounds are vulcanised at a temperature of 170°C. After an average of six minutes, the moulds are opened. The rubber tyre now has its elastic properties. The curing tubes are fully recyclable and fed back into the process after cooling. At the end of the production process, every single tyre is subjected to rigorous quality checks. Tyre after tyre is carefully inspected by hand before earning its next quality control stamp. Trained staff spot check production batches for weight and true running. The tyres are now ready to be shipped to Reishof in Germany. So what needs to happen for serious production of the tyre to be realised? Teams are simultaneously engaged in research and development at both the production factory and headquarters. Here, countless prototypes are tested, while some are even battered without mercy. Thanks to the laboratory and the modern machine park we have here, we can bring a top product to the market, because we have previously tested it on hearts and knees. We have a abrasion test here, where we can rub off the tyre in accelerated time and evaluate whether the rubber compound is durable. When it comes to performance, it is often also about accuracy. For this purpose, we have the Snakebyte tester. With simple tools, we can check whether a tyre can satisfy the customer. The testing procedures not only determine what a tyre can withstand, they also establish the performance a tyre offers. This is extremely important in a means of transport that depends on muscle power. All these findings are applied to the formulas for new rubber compounds. My and my team's job is to investigate new rubber compounds to produce innovative tyres. In this way, innovation finds its way back to production, just like in tube production. To ensure air retention in fibre tubes, the high purity of the material is every bit as essential as the chemical composition. A machine called a strainer uses high pressure to force the rubber compound through seven different filters in order to purge unwanted particles. To this end, an intensive cleaning process is performed several times a day. An extruder forms a continuous malleable tube from the cut material. This is cut to the right length. Then fitted with a valve and given a number for quality control purposes. The intermediate product is then taken on a trolley to the splicer station, where the loose ends are pressed together precisely to form a tube. The bonding of the seams and the valve guarantees a high degree of tear resistance. Next, the tube arrives at vulcanisation. As in the case of tyres, this process gives the tube its elastic properties and its high resistance to external influences. Of course, the tube does not require a tread. Various quality assurance steps are then performed. Once inflated, each tube is stored for 24 hours to check for air retention. Random testing in a water tank also confirms air retention. Provided everything is in order, the air is extracted, the tube is printed on, wound up and packaged, ready for shipping. For many tubes and tyres, this is the start of the journey to Schweibe headquarters in Germany. Upon arrival at the Reichshof headquarters, warehouse staff receive the goods and organise their distribution. The warehouse holds millions of tyres, tubes and accessories. On the next floor up, final spot checking is carried out for quality assurance purposes. This completes the series of checks in line with the dual verification principle. When the products have passed these tests, they are finally ready to travel thousands of kilometres attached to our customers' wheels. All around the world.