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Why choose Challenge? What’s the point in training till you drop if you’re going to be losing efficiency and speed in your tires? Ride quality is paramount, and no other tire offers the supple, responsive traction of a Challenge tubular, eliminating barriers in achieving your maximum speed and potential. Supple tires not only offer a sublime ride, they reduce rolling resistance, and enable more precise handling and a greater range of pressures. They adapt quickly as the tire changes shape while cornering and rolling, which increases road surface contact and grip while cornering, plus shock absorption as you pass over irregularities in the road. When searching for a handmade tubular or handmade clincher, consider the following factors, all of which play a role in the tire’s performance. Tire Construction Basics (#) To understand what makes Challenge Handmade tire construction special you must first understand the basics of bicycle tire construction. 98% of the world’s bicycle tires are wire bead clinchers made with a nylon casing saturated with synthetic butyl rubber and a synthetic butyl rubber tread. Those components are cooked or vulcanized into a horseshoe or U-shaped circle to be mounted on a steel or alloy or carbon clincher rim. This system maximizes the durability and long life and minimizes the cost of the tire. Car tires, motorcycle tires, airplane tires and giant truck and tractor tires are all made much the same way. Repeat, this is the cheapest, most cost efficient way to make a tire. Butyl Rubber (#) Butyl rubber is that material you find in bouncy playground balls, bladders of footballs, basketballs and soccer balls (to make them bounce) and cheap, standard bicycle inner tubes. The main attributes of butyl rubber are its inexpensive price and ability to bounce. Vulcanized Clinchers (VCL) (#) To make a standard Vulcanized Clincher (VCL), nylon mesh is dipped in a bath of butyl rubber and then calendared (squeezed) between big steel rollers to create the casing. Because the thread count is so low, there are big spaces between threads to fill with bouncy butyl rubber. The final casing is about 50-70% nylon and 30-50% butyl rubber (higher thread count, less butyl rubber). The casing is combined with the butyl tread rubber and vulcanized into the clincher shape. VCL is durable but not comfortable or high performance. Strong, cheap standard nylon/butyl rubber tire systems for cars, trucks, airplanes, tractors and motorcycles may be attractive when you have a sophisticated suspension system and padded seats separating you from road shock. When you have a lightweight, high-performance bicycle where only six or eight kilos of super stiff carbon fiber (wheels, fork, frame, bar, stem, seat post and even saddle shell) highly optimized for efficient power transmission separating you from the road or trail, a bouncy (at low pressure) or stiff (at high pressure) VCL tire system delivers a painful, exhausting and inefficient ride when it is dry - and a quite dangerous ride when it is wet. Vulcanized Tubeless Ready (VTR) (#) The highest level of performance offered by car, truck and motorcycle tire manufacturers is a vulcanized tubeless system. While this is an old technology for cars and trucks, for bicycles it is relatively new and did not even have an internationally accepted design standard (ISO or ETRTO) until this year. By eliminating the inner tube it is possible to lower the weight and theoretically create a softer, more comfortable, more efficient, lower rolling resistance tire system by running lower tire pressure. The reality is a little different as extra rubber needed to seal the air lower pressures tends to defeat the concept of “high performance” tubeless. A tubeless system has a super tight fit on the rim to maintain the seal and can be run without sealant. Most tubeless tires are actually tubeless ready (TLR), able to run tubeless by adding a sealant but also able to be run with an inner tube when assembled and sold to make test rides and a quick sale possible. Regardless of which tubeless system is used, two concerns arise: A tubeless system requires more maintenance than a system with an inner tube. This is not a big problem in a car or truck or motorcycle that you take to a shop for service, but can be a big problem for cyclists out on the road or trail, It is still impossible to make a tubeless system perform like a handmade tubular system. This is why top pros in every bicycle segment still use tubulars. Challenge started introducing Vulcanized Tubeless Ready (VTR) tires this year because the ISO and ETRTO standards for proper VTR tire and rim fit have finally been completed. These standards ensure your safety and your ability to fit and service the tires with hand tools. Road (or Trail) Shock and Rolling Resistance #1 (#) Understanding how road shocks are propagated through the bike is critical. Rolling down the road or trail it impacts cracks, holes and rocks perpendicular to the tire surface. The force of these impacts is split into two components - vertical and horizontal. The vertical force is passed up through the wheels, spokes, fork, frame and into the hands, feet and backside of the rider. This force creates pain, fatigue, poor traction and cornering therefore reducing control especially in the wet. Twenty years ago steel or titanium or alloy forks, frames and components would have absorbed some of these shocks. Now with all these parts made in carbon fiber optimized for efficient power transmission, all the shocks are passed into the rider. For 15 minutes these shocks may be OK but after an hour or more, the cumulative impacts are both painful and fatiguing. The compliance of a properly inflated tire has been measured to be 20 times greater than the entire rest of a modern carbon bike – bringing back some comfort and control where only pain existed. A soft, supple tire (especially a tubular) will protect the rider keeping the tire on the ground to optimize traction and cornering. The horizontal force of impacting these bumps pushes the wheel and bike backward, forcing the rider to apply more power. This force is rolling resistance (Crr). On a polished indoor track with slick tires at high pressure this rolling resistance is quite small but it grows quickly as even small imperfections on an outdoor concrete track, asphalt road or dirt or gravel trail grow. Crr doubles or quadruples on poorly maintained roads full of cracks and potholes, gravel roads and rocky mountain trails. Why Challenge Handmade Tires? (#) Challenge Handmade Tires combine attributes to create the most comfortable and low rolling resistance tires: Soft, supple casings Soft natural rubber treads with special compound Unique, seamless latex inner tubes Special puncture protections Sidewall sealants Challenge Handmade Tubulars (HTU) and Handmade Clinchers (HCL) (#) We make Challenge Handmade Tires 100% in our fa mily-owned factory in Thailand, 90 minutes down the coast from Bangkok. We are in Thailand because that is where our natural rubber and latex is sourced, where we can control the raw materials and where the world’s rubber and latex experts work. Challenge Handmade Tubulars (HTU) (#) Our Handmade Tubular (HTU) tires perform better than any tubeless system! This is why they are raced by all of the top athletes and teams in every cycling segment. The latex inner tube us cradled inside the high quality casing that is sewn shut, forming a soft protective layer for the delicate tube. A base tape is glued over the sewing for protection and to absorb the adhesive later applied to hold the tubular on the rim. The carcass is mounted on a rim, inflated and a special natural ru bber tread is precisely glued on top. Puncture protection layers and sealants can be applied to the finished casing, depending on the tubular’s use.
- Challenge Criterium SC Open Tubular vouwband-Zwart-700x25 Adviesprijs € 59,90€ 44,90