What makes a good tire?
What do riders mean by a good tyre? It rolls smoothly and quickly, rides comfortably, grips and handles well, and resists punctures. Every cyclist, from élite professional to ecominded commuter, can agree on these qualities.
These qualities depend almost entirely on how well the tire’s casing is made. And the most important factor here is the quality of the fabric used to make the casing. The fabric may be made of nylon, Corespun, aramid fiber, polycotton, or a mixture of these. The finer the threads, the denser the weave.
We express this as TPI – threads per inch. The greater the TPI number, the higher the quality of the tire. Why is this?
The casing is more flexible, so more of the tire’s surface is in contact with the Tarmac, giving better grip.
Fabric with a higher TPI count is thinner and more flexible, so the tire’s casing conforms closer to the surface the tire is being ridden on, with less shock and smoother rolling.
High TPI count means lower rolling resistance. Most of a tire’s rolling resistance is caused by the rubber deforming. Because there is less rubber, tires with a higher TPI count convert more of the rider’s energy into forward motion.
Vittoria tires are classed by their TPI. Nylon casings range from 26 to 220 TPI. Cotton and Corespun casings range from 220 to 320 TPI. (See in the diagram how the TPI count maps against our range.)
The 320 TPI of our top Evo models is the highest thread count currently available in a bicycle tire. These are the tires sought out by riders who must have the very best.
The different textile structures, making the casing’s soul: the more dense the net is, the more flexible the casing.
What is a tubular?
There’s no mystery about tubulars. The inner tube is fully enclosed by the casing, which is secured to the wheelrim by glue. By contrast, a clincher is open – the bead at the opening hooks on to the inside of the wheelrim to secure the casing.
Technically, a tubular is a toroidal form – think of it as a very skinny donut. The outer surface carries the tread, which may be attached to the casing by vulcanising – a mechanical process– or glued by hand. Hand-gluing avoids the high temperature of vulcanising and, though expensive, is preferred for top-quality work.
The tubular is completely round in section – we say it has a constant casing radius. This gives it two big advantages over the clincher.
What is a tire?
The familiar pneumatic tyre consists of three parts: casing, tread, and bead (plus, usually, an inner tube). Casing is made of a fabric coated with rubber. Nylon is the fabric most commonly used. The number of threads per inch (TPI) gives an idea of how finely woven the fabric is, and how the supple the casing is. The casing fabric of Vittoria’s top tyres is a mixture of polycotton and aramid fiber exclusive to Vittoria.
Tread provides the contact with the road surface. A high-performance tread compound is a mix of rubber, silica (SiO2), carbon black, and other proprietary ingredients. For extra performance, Vittoria’s top tyres utilize a compound with an admixture of finely-chopped Kevlar® fibers. Tread pattern depends on the tyre’s intended use: from slick for dry, smooth surfaces, to grooved for wet, rough ones.
What is TPI?
TPI stands for Threads Per Inch (2.54 cm) referring to a one inch length of casing. The casing is the heart of the tire or tubular and is made of Rubber + Threads (Nylon, Cotton, Kevlar, Corespun…). TPI is calculated by counting the number of threads contained in one inch (2.54 cm) length of casing.
What do the sidewall inscriptions mean?
Tire sidewalls carry on the following informations: maximun and minimum pressure (always check rim max pressure which is not rarely less than tire’s max), country of origin, sizes of the tire in French form (700×23) and ETRTO form (23-622).
What is the ETRTO?
ETRTO means European Tire and Rim Technical Organization and is the tire and rim standard. An ETRTO size of 37-622 means 37mm tire width and 622mm tire bead inner diameter.
The primary purpose of the ETRTO is to give an unequivocal match of rim and tire mounting compatibility.
What is the Pit Stop Road Racing and how does it work?
Pit Stop road racing is an “inflate and repair” cartridge latex based, ideal for either tubulars and clinchers and tubeless tires systems. The universal head is compatible with Presta, Schrader and Regina valves so it is able to inflate almost every standard of the market.
The Liquid latex contained in the can is injected in the tube (both tubulars or clinchers) as a foam, filling the tube and repairing holes up to 1mm. It turns back to liquid after a couple of minutes, especially if riding immediately after the injection. In liquid form it will keep on protecting against possible punctures and the typical pressure loss of latex tubes which are commonly used on high-end tubulars.
The mixture between latex and CO2 contained in the cartridge is optimized to inflates a 21-28″ tubular up to 6 bars, far enough to get home or finish the race.
Latex density is a compromise between an easy erogation (it needs to enter inside the valve) and repairing strength.
A few key points to remind:
- The repair is definitive, you don’t have to change the tube or the tubular.
- You can use the Pit Stop before having a flat as a preventive.
- The Pit Stop seals the porosities of the latex inner tubes resulting in reduced typical air loss of latex inner tubes.
- It offers a minimum of 3 months prevention after injected.
- Inflation pressure can be normally fine tuned with a floor pump after Pit Stop has been injected.
Do you have a factory outlet?
While we do not have a factory outlet, you can find Vittoria products in quality bike shops all over the world! Please refer to our Dealer Locator to find the nearest shop that carries our products.
How can I set the real tire circumpherence on my computer?
The most accurate method to measure the real tire outer circumpherence is by measurin it on the ground: jump on your bike, take the valve as reference and make a mark on the ground, do a complete rotation of the wheel moving forward in a perfect straight trajectory and mark down the valve again. Measure the distance between the two marks and that is the real circumpherence.
Any other way to measure it doe not take into account the lowering given by rider’s weight (which effectively decrease wheel radius on the contact point with the ground) and the different shapes given by each rim width. Different rims and different pressures do result in different circumpherences in fact.