Tech feature: Inside Continental's tyre factory, June 17, 2005 All stitched up Maria Stolz works on a Competition tubular Photo ©: Gerard Knapp The red material is the Vectran layer Photo ©: Gerard Knapp The rubber tread then needs to be vulcanized Photo ©: Gerard Knapp And so begins the stitching process. Photo ©: Gerard Knapp The cotton layer helps protect the inner tube Photo ©: Gerard Knapp This is the difficult part - stitching the casing together Photo ©: Gerard Knapp Another view of Barbel's work. Photo ©: Gerard Knapp Here, the casing is finally hand-stitched with thicker thread. Photo ©: Gerard Knapp After the final stitching process, the tyres are inflated Photo ©: Gerard Knapp After checking the tubular was air-tight for 24 hours Photo ©: Gerard Knapp Then they end up here Photo ©: Gerard Knapp Continental's bicycle tyre division is a small part of what's now a huge company, but it's where the German rubber started out, and Conti is still fiercely dedicated to making bike tyres - as are its employees. Gerard Knapp met some of the people who craft Continental's tyres, and found out what goes into a hand-made tubular and why they're still the pro's choice. The paved, well-worn flooring rumbles underfoot, the mechanical clatter is so loud that hearing protection is required, giant steel rollers hiss with steam as they compress mysterious, raw black compounds into wide thin layers. And then there's the smell - the odour of baking rubber is over-whelming, carried by the high relative humidity and penetrating the nasal cavities so it remains for days after. You look around as burly men wearing rubberized aprons wheel large pallets of mysterious black materials among the giant machinery. Welcome to a tyre factory. I had waited some time for this, ever since seeing Fritz Lang's classic B&W silent science fiction film, Metropolis. I'd visited many factories, but none had ever captured the scale, sight, smell and sound of Continental's factory in Korbach, Germany. Clinchers versus tubulars - cycling's longest-running argument Continental makes both tubular and clincher tyres, but sales of clinchers massively outweigh those of tubulars. Aside from the skill and dedication of its staff, that's one reason why Continental's tubulars are still hand-made; there just isn't the volume in tubulars to justify the enormous capital investment that would be required to build the machinery needed to assemble these complex constructions. Ever since high-quality lightweight clinchers and rims began to appear in the 1970s, cyclists have argued about which design is superior. Clincher fans point to the repair issues mentioned in the main story, while tubular aficionados ask how far the clincher camp can roll safely on a flat tyre in a race. So what are the main issues? Rolling resistance. The available data seem to favour clinchers by a small margin. Conti says its Competition 22mm tubular rolls slightly better than its GP 3000 23mm clincher, but other comparative data - such as Jobst Brandt's figures from Japan, and tests conducted in the 1990s by Tour magazine - show the best clinchers roll slightly faster than the best tubulars. The difference, however, is a matter of a few percent in values that are already small. Weight. Tubulars still win this one hands down. The very lightest tyres are still tubulars, but for all-round racing use it's almost a draw. But rims for tubulars are still lighter because they are a simple rounded-rectangle cross-section with no hook, so a tubular wheelset can save a couple of hundred grams over clinchers. And if you have deep pockets, then all the very lightest wheels have rims for tubulars because it's relatively easy to make a light carbon tubular rim, considerably harder to make a carbon clincher rim. Practicality. You'd have to call this one a draw. For races with tech support, when you're not going to replace your own tubes, the ability of a tubular to be ridden flat till tech support finds you is a plus. For almost every other type of riding, the need to carry glued, reliable spares, and the hassle of repairs gives the nod to clinchers. Feel. Tubular fans claim they feel better on the road and have a rounder shape that corners better. Clincher users say they're dreaming and any tyre has a round cross-section where it's not attached to a rim. This very quickly becomes a religious war, but at least no oil-rich desert nations get invaded as a result. There's no clear winner, which is why pro teams still use either or both systems. You weigh up what matters most to you, and you take your choice! An example of the marketing materials featuring the factory staff. Photo ©: Gerard Knapp Given it was built around the same time as Lang made his film - at the height of the industrial boom in Europe - it's not surprising, but unlike Lang's film, there is no worker revolt. Indeed, it's something of the opposite as the company has employees with decades of service, still producing tyres for the company. The production of bicycle tyres is at the root of Continental's foundation. The company started business making bicycle tyres, even if the bicycle tyre department is now one of the smallest divisions of the German conglomerate. Nonetheless, the company is extremely proud of its heritage, as well as the service and expertise of its employees. Many of you may have seen the striking monochrome advertisements and marketing materials that Continental has released over the past 12 months, focusing on these extraordinary employees at its Korbach factory, nestled away, as they are, in this enormous complex that also produces motorcycle and some car tyres (Conti has other factories in Germany). The bicycle tyre specialists work in a somewhat more pleasant environment, two floors above the ground-floor raw materials engine room. But it was this combination of environment, people and expertise that struck senior Continental marketing executive, Jorg Malcherek, when he went to the Korbach factory. He thought of these typically German qualities as strengths, so he built a marketing campaign around them. He brought in pros like T-Mobile's Eriz Zabel and Credit Agricole's Thor Hushovd to pose in the factory with the (somewhat overwhelmed) workers who produce every tubular tyre that Continental sells around the world. (Zabel, in particular, was said to be very popular among the workers.) I suspect that for many readers, the whole 'tubulars experience' is foreign, but every cyclist should experience riding on a set at least once in their cycling life. No matter how good 'clincher' tyres have become, and they're very good, nothing beats a set of tubulars (and we have science to back this up, too). But for most of us that have used tubulars for any length of time, a flat is not fun; they're buggers to fix. (Quick quiz: what is the number one reason many professional riders still largely insist on using tubular tyres? Answer: Their 'run-flat' ability. That is, a tubular can go flat and it is still possible to ride on the wheel, at least until the rider is in a better position to receive service. Of course, this will probably damage the rim and tyre almost beyond repair, but in a race environment, such collateral damage is acceptable. If a clincher tyre goes flat, it is very dangerous indeed to keep riding, as the tyre can be dislodged from the rim and then all hell breaks loose as it wraps itself around the wheel. But because tubulars are glued to the rim - and we mean glued - they remain in one piece. Hence their antipodean nickname - singles.) Back to repairing them. It is when your prized tubular gets a puncture you appreciate the work that goes into making one. After removing it from the rim (gorilla-strength required. Okay, that's an exaggeration - but only a slight one) you have to locate the puncture by time-honoured method of pumping up the tyre as quickly as possible and dunking it in a bucket of water to find the bubbles. Then you remove a base layer tape (again - glued) and the casing is revealed, which is stitched together very neatly. Then, you unpick the stitching to access the inner tube, patch the hole, and cross your fingers you've done a good job. That's because you have to stitch the casing back up with industrial-thick needle and thread - and this is an art in itself, as you need to ensure the casing remains aligned and your tyre doesn't go out-of-shape. Then you re-inflate the tyre, and hope it doesn't go flat again. If it holds air okay, you can then re-glue the base tape. Then you have to glue it back to the rim. By now, you're probably saying "why bother?" Indeed, that's why modern clinchers are a revelation, but what clinchers can't do is offer the same comfort, feel, lower rolling resistance and run-flat capability of tubulars. I've always thought of tyres (and wheels, to some extent) as being like loudspeakers to a hi-fi system; there is no easier way to improve your enjoyment than spending up on good wheels and tyres. Smokes, or rubber tubes? Photo ©: Gerard Knapp And for this reason, there is still a market for the very best cycling tyres you can buy. Continental takes immeasurable pride in their product and it is hard to think of any other piece of the highest-end cycling kit where you can learn the names of the core group of four women who make every one of them. They are: Maria Stolz, Androniki Mpontia, Barbel Disterheft and Margit Halle. And as a hapless repairer of tubulars in the past, I dips my lid. Love your work. See also: Vectran keeps Conti inflated - Conti talks tyre tech