All open tubulars produced by Challenge are special products made by hand. Machines are not able to produce them and the manual skill required in each phase of production is very high.
Challenge's casings are produced with the latest materials like Corespun (a combination of cotton and polyester). Corespun thread is very fine and allows Challenge to obtain very supple and strong casings with low weight and high strength. Corespun casings have a high TPI count that can reach over 300 TPI. A special fabric is placed between the tread and casing to increase puncture resistance, what Challenge terms its PPS (Puncture Protection System) technology. Challenge's production processes avoid any vulcanization process to enable all materials to keep their suppleness and provide a very smooth ride with low rolling resistance.
What is a "Challenge Open Tubular"? An open tubular is produced like a sew-up and uses the same materials and production processes and provides the same ride quality, but mounts to standard clincher rims like standard clinchers. Instead of being sewed together with an inner tube inside at the end of the production process as sew-ups are, beads on open tubulars are made by folding the open Corespun casing around Aramid fibers. For this reason an open tubular gives a very similar ride to that of a sew-up. If you use a latex tube with an open tubular, the difference from a sew-up is nearly indistinguishable. Thus, the open tubular provides the ride quality and performance (except perhaps for weight) of a sew-up, but provides the convenience of folding clinchers. Mounting an open tubular on a wheel is the same as mounting a standard clincher, and repairing a punctured open tubular is just as easy as repairing a punctured clincher.
The tread on Challenge open tubulars is hand-glued onto a casing that was previously mounted on a rim and and inflated. By using this production method, the tread is relaxed on the casing and does not suffer any tension when the tire is inflated. The result is lower rolling resistance, increased comfort, precise handling, and better grip.
Challenge's open tubular design and method of manufacture are not radical and Challenge is not the only premium tire manufacturer to employ them. The superb Vittoria Servizio Corse uses an identical design, 320 TPI Corespun casing, and method of manufacture. This is not extraordinary. Nor is it some closely guarded trade secret. Rather, this is simply how premium bicycle tires are manufactured.
Sidewalls are natural latex in color to highlight the quality of Challenge's Corespun casings. Closely examine a Challenge open tubular, both inside and out. There is no seam. Look for imperfections in the Corespun. There is none. And the translucent latex shows everything. There is no attempt to hide anything because there is nothing to hide.
In recent years, some tire companies have tried to market and sell all-black tires to the consumer by claiming that such tires are "F1 technology". This is a joke. The vast majority of these all-black tires are junk tires with cheap casings hidden behind the outer black layer. The tread and sidewalls are hot-molded onto the casings, which stiffens the casings, reduces ride quality, and increases rolling resistance. If you ever see rubber "needles" on a tire, walk away. That tire is junk. You will never see rubber "stubble" on a Challenge open tubular.
Furthermore, all-black tires are hideously ugly, make your bike look terrible, and make you look like a Fred. Eddy Merckx never rode black tires. Neither should you.
The Criterium is a handmade tire designed for road racing, but is equally suitable for general road riding.
The Criterium is a 700x23C tire, which might look chubby on an older machine like John's old racing bike from the 1980s. Most road-racing tires from this period were 700x20C. However, a narrower tire is not necessarily faster. Challenge claims that the contact patch of a 23C tire is the same as that of a 20C tire. The difference in rolling resistance is minimal but in cornering grip the 23C has far more grip and stability. The result is that a 23C tire is actually faster overall than a 20C tire. At least this is what Challenge claims.
Another road option from Challenge is the Parigi-Roubaix open tubular.
Every spring in northern France, racers ride the toughest and most romantic bicycle race in the world: Paris–Roubaix. The race was first raced in 1896 and continues to this day. Only two world wars have stopped it.
Paris–Roubaix is raced over ancient cobblestone roads that test both man and machine to their limits. Each secteur of pavé has a distinct character and presents different challenges to the riders. Many of these secteurs are as famous as the hors categorie climbs of the Tour de France because numerous races have been decided on these secteurs. Names like Wallers-Arenberg, Mons-en-Pévèle, and Carrefour de l'Arbre are merely names of various secteurs of bad road, but they will live forever.
Roubaix champions live forever as well. Their names are even engraved into plaques in the Roubaix Velodrome's showers so that all of the riders are reminded of all of the champions who came before them. Shown above are the plaques for Francesco Moser and Octave Lapize. Both men are famous for winning Roubaix three times in a row; Moser in 1978, 1979, and 1980, and Lapize in 1909, 1910, and 1911. In the background is the plaque for Il Campionissimo Fausto Coppi, who won in 1950.
Two of Roubaix's greatest riders are Belgians Eddy Merckx (three victories) and Roger de Vlaeminck (four victories). These two men are also members of a very elite club of only three men in history who have won all five Monuments of Cycling (Milano–Sanremo in Italy, Ronde van Vlaanderen in Belgium, Paris–Roubaix in France, Liege–Bastogne–Liege in Belgium, and Giro di Lombardia in Italy). Eddy Merckx is the only man ever to win all five Monuments twice. Merckx also won all three Grand Tours 11 times (five Tours de France, five Giri d'Italia, and one Vuelta a España), won the World Championship Road Race three times, and held the Hour Record. If you think "Lance Armstrong is the greatest cyclist who ever lived", you might want to think about that.
Perhaps no other rider has delivered in Paris–Roubaix than Roger de Vlaeminck. de Vlaeminck holds the Roubaix record with four victories. He also finished second four times and third once. This record may never be surpassed. But much more than mere numbers was de Vlaeminck's total mastery of the pavé. "He had an amazing feel for this race, rolling over stones as if he were on asphalt", recalls de Vlaeminck's directeur sportif Franco Cribriori. "The evening of Paris–Roubaix, we threw out all of the wheels except those belonging to Roger, which were still serviceable. In fact, they were like new." de Vlaeminck's mastery and successes at Roubaix are impressive enough that this virtuoso of the pavé has become known by the moniker Monsieur Paris-Roubaix.
Roubaix champions Sean Kelly and Eric Vanderaerden force their way over the Arenberg pavé. The Paris–Roubaix cobbled secteurs are rough enough that the machines are fitted with special equipment like heavy-duty tires and Special Service des Courses rims to survive the pounding.
It was for these riding conditions that Challenge created its Parigi-Roubaix tire. This 700x27C is designed to provide a very compliant ride and severe puncture resistance over the roughest roads. Like all Challenge open tubulars, the Parigi-Roubaix mounts and repairs like any other folding clincher, but provides the ride quality and performance of a sew-up.
The Parigi-Roubaix features a fine herringbone tread. This is an excellent general-purpose tire if you want a very soft ride on asphalt or if you ride a lot of grated dirt roads. Just make sure your road frame has the clearance for 700x27C tires.
Even if you don't ride over pavé (almost none of us does), keep in mind that the Parigi-Roubaix is nearly identical to the tires used in the early Grand Tours. The early Grand Tours featured paved riding in town but dirt riding in the country. If you like to do this style of riding, the Parigi-Roubaix is ideal.
Contrary to popular belief, you don't require knobbies to ride on dirt roads. Generations of Tour riders rode with simple herringbone tread over dirt roads and so can you.
This is true even in the wet. A young Louison Bobet leads Gino Bartali over the Col de la Croix de Fer. This famous hors categorie climb links the French towns of Bourg-d'Oisans and Saint-Jean-de-Maurienne and is one of the most difficult climbs around. If these Giants of the Road can climb and descend a wet Iron Cross on herringbone tread, so can you. You certainly won't match their pace, but it will not be because of your equipment.
Yet another style of riding is over rutted and hardpacked trails. These trails have been severely rutted from rains, but are dry and hard for most of the year.
Challenge designed its Grifo XS tire for riding fast over dry/hard terrain. At 700x32C and 340g, the Grifo is both larger and heavier than the Parigi-Roubaix and will not fit most road-racing frames. This is an excellent general-purpose tire for all-terrain machines.
The center of the Grifo XS's tread is a coarse file tread,
with baby knobbies on the sides. This is an excellent general-purpose trail tire.
At road pressures, the Grifo XS' side knobbies do not wear down and stay nice and sharp for the trail.
If you actually ride to the trails rather than driving there in your wannabe team car adventure lifestyle mobile with your bikes on the roof, the Grifo XS is excellent.
For true muddy conditions or cyclocross racing, Challenge makes its Grifo tire. Multiple Cyclocross World Championships have been won on this tire.
The Grifo features a true knobby tread in a unidirectional pattern.
Like the other Challenge tires we sell, the Grifo is an open tubular design with all of its advantages over standard clinchers.
Whatever Challenge Tires you fit to your bike, pump them up with a Silca Pista Floor Pump. The Silca Pista is a classic in the cycling world and the floor pump by which all others are measured. Unlike other plastic and disposable floor pumps, the Pista features all-metal construction and is fully serviceable with readily available replacement parts from Silca. The Pista will last you the rest of your life (John still uses the 30-year-old Pista from his childhood). The Pista provides ample volume for inflating road and cyclocross tires. The wooden handle is comfortable and pleasant to use. When not in use, the hose clips to to the main shaft. This is a great pump and a joy to use.