As with many Vision wheels, the Metron 40 -is available both in a clincher, here and…
… the tubular version. Each have the 40mm section rim, but of course each has the correct rim profile for the appropriate tire type.
In general, there are three tire widths on road bike wheels: 23mm, 25mm and 28mm. Traditionally, 23mm was used for racing with 25mm and 28mm employed for rougher roads. That’s particularly true of 28mm-wide tires and is why they’re often used at cobbled classics like Paris-Roubaix.
However, recently 25mm tires have grown in popularity for racing, too, because studies have shown that they actually have a lower contact point than 23mm tires. They also perform better on rough roads. This means that a 25mm tire has lower rolling resistance than a set of 23s and is more comfortable. Just check that your frame and brake clearances will allow 25mm or 28mm widths.
A 25mm tyre width would suit a wheel like the Team 30, which is a great training wheel and entry-level racing choice. With a top-end race wheelset like the Metro 81s, you could play around with 23mm upfront and 25mm in the rear. This will provide a good balance of aerodynamics, speed and comfort.
Every tire features a maximum tire-pressure figure on its sidewall. Traditionally, clinchers should be well inflated, so around 8 bar (116psi). This reduces contact area and, in turn, friction. Then again, tires are a rapidly evolving component and there’s an argument that if you pump them to this figure, the tire will in reality be ‘bouncing’ slightly along the road and reduce efficiency. Then again, if it’s not inflated enough – anything lower than 6.2 bar (90psi) – there’s an increased chance of a puncture (though this pressure’s not a bad choice on wet roads because of increased grip). So try around 6.5-7 bar (95-100psi) and see how you get on. It should strike a good balance between comfort and speed.
Also consider rider weight, as a heavier rider will need greater tire pressure than a lighter rider. A good starting point is to take your weight (in kg) and divide by 10 to give the correct tire pressure in bars.
Finally, which tire for which season? In the winter, where roads are filled with detritus and punctures are more common, you want something with increased puncture protection. Yes, this increases weight but it’s worth it. Lower-end models will simply feature an extra later of rubber. More expensive models will use a stronger material – Kevlar is common – down the center and reinforced sidewalls.
Also, fight intuition and go for a slick tire. While there are models with deep tread, slick tires actually present more of a surface area to the road so grip better. (Cars need tread to prevent hydroplaning, which is common at speeds approaching 100mph!)
Come the summer, when punctures are rarer and you’re after more speed, look for a tire that has a high TPI (threads per inch) count. A high number refers to finer nylon threads used in the casing, which results in less rolling resistance and more speed. Just bear in mind that finer threads are weaker so the chances of puncturing are higher.