Tubeless for the road - Ultremo ZX
It’s not only the fastest tire Schwalbe has ever produced, but also the safest: The Ultremo ZX tubeless raises rolling resistance and puncture protection to a higher level. Schwalbe is the first leading supplier in the racing bike sector to put a tubeless tire on the road.
“We’ve had the idea of applying the tubeless technology used for mountain bikes into racing bikes for ages”, says Christian Lademann, Schwalbe’s Product Manager for racing bike tires. “But in spite of our experience with tubeless in the MTB field it was technically quite challenging to produce a high-pressure tubeless racing bike tire.” With the special carcass design and development of the carbon bead, Schwalbe engineers broke new ground in bicycle tire technology. After three years’ development, hundreds of test rides in training and competition, as well as numerous prototypes, Schwalbe is now enthusiastic about its tubeless tires for racing bikes – and with them, aims to reach the top step of the podium.
Christian Lademann: “We have been able to further develop the system and overcome challenges such as high pressure and ease of fitting. The Ultremo ZX tubeless is the fastest tire we have ever produced! It is even faster than the mere 160 gram Ultremo ZLX, the lightest tire in our product range.”
Advantage of the tubeless system: No sudden loss of air
The advantages of tubeless technology have been undisputed for years as far as the mountain bikes are concerned: In case of a defect, there is no sudden loss of air or the valve shearing off, the air escapes only very slowly. Since there is no tube inside, the tires roll more easily. In addition, the bike can be ridden with slightly lower air pressure – all advantages that have been firmly established for decades as far as motorbike tires and car tires are concerned. So why not simply apply the system to the racing bike?
The challenge was the high air pressure
“The crucial point was the high air pressure needed with racing bike tires”, admits Christian Lademann. Were it not for the high pressure of over eight bar, there would have been top-class tubeless racing bike tires long ago. Although there has been a tubeless tire for racing bikes on the market since 2006, the breakthrough to a new system took a long time.
“The prerequisite for us was that, with a pressure of nine bar, the tire had to sit firmly on the rim“, says the Product Manager. Such high pressure meant the system had to be absolutely air tight and remain so. At the same time, fitting had to be easy for an amateur. Therefore, the bead core mustn’t be too thick, because racing bike rims are far narrower than MTB rims. Furthermore, it had to be possible to inflate the tire with just a track pump, i.e. without a compressor. And finally, the weight of the system had to remain definitely less than 300 grams. 295 grams per tire doesn’t sound much like a light weight, but it’s exactly the total weight of the Ultremo ZX with a standard tube.
These problems could only be solved after Schwalbe adopted completely new approaches, both as far as the design of the carcass was concerned and the material of the folding bead. For the first time, Schwalbe used carbon fibers in the bead core in order to achieve the necessary tensile strength and prevent the tire jumping off the rim. The complete carcass not only has an inner tube vulcanized into the tire, the so-called inner liner, but it has also been additionally reinforced all round. The all round protection also increases the puncture protection, because the tire shoulder and side wall are now much better protected against cuts.
Optimum results in terms of rolling resistance and safety
“Above all, the tire is really fast”, stresses Christian Lademann enthusiastically. The fact that it rolls so lightly is due to the tire and tube being vulcanized to form one complete component. This saves a great deal of unnecessary friction and lowers the rolling resistance dramatically. The tubeless Ultremo has a rolling resistance even lower than the lightweight Ultremo ZLX.
“Just as much or perhaps even more, cyclists will appreciate the excellent safety”, adds the former professional racing cyclist Lademann. Puncture protection is considerably higher than in the case of folding tires or tubular tires. The dreaded sudden loss of air due to a burst inner tube is a thing of the past. Because the inner tube has been vulcanized into the tire, it can’t burst – consequently, in case of a puncture, the air escapes only very slowly. Burst inner tubes as a result of overheating on long, steep descents are therefore completely impossible! In addition, the reinforced carcass has doubled snakebite protection.
Schwalbe recommends using the tubeless racing tire with 30 ml sealant (Doc Blue Professional). It makes the tire even more impervious to typical damage as a result of shards, thorns or flints, and has no negative affect on the rolling resistance. If the tread or side wall is pierced, Doc Blue Professional seals it, even at high pressure, within a fraction of a second. “The interaction between sealant and tubeless tire makes riding safer than any protective belt!” according to Lademann.
In order to be able to fit the tubeless version, special wheels are necessary. The rim flanges must form a hermetic seal with the tire. There must also be no spoke nipple holes in the rim well. The valve is directly inserted into rim. “Although fitting takes a bit of practice, it is by far not as time consuming as gluing tubular tires. A compressor is not absolutely necessary, but a good floor pump is.”
Tubeless tires are usually run with slightly lower air pressure. As a result, the tire has much better road contact and provides the cyclist with better traction and cornering grip.
Tubeless for racing bike tires? Schwalbe puts its faith in a sea change!
Will there be a sea-change as far as racing bike tires are concerned? The test results have been absolutely convincing. The Ultremo ZX tubeless gained the confidence of the test cyclists and some of the professionals in the Radioshack Nissan Trek WorldTour Team that is equipped with Schwalbe tires. Fabian Cancellara tested them during the Tirreno-Adriatico tour.
Christian Lademann is convinced that “the tubeless technology on the racing bike solves the age-old tire technology conflict between rolling resistance, puncture protection and wet grip at the highest level. We are absolutely confident that tubeless technology will become established in the field of professional, amateur and everybody cycling.”
Ultremo ZX Tubeless will be available in the specialized trade as of June 2013. Schwalbe’s Ultremo ZX tubeless introductory offer: A pair of tires with Doc Blue and Easy Fit.