If you’re looking for performance and a ride feel similar to that of tubular tires, Specialized Turbo Cotton tires are among the very best on the market, offering low rolling resistance, comfort, and responsiveness—as we were able to confirm after riding 2,500 km on a variety of roads. 

By Guillaume Judas – Photos: 3bikes.fr

This was one of the major new developments spotted at the 2020 Tour de France: some pro riders are now competing at the highest level with clincher tires instead of traditional tubulars, starting with Julian Alaphilippe (Deceuninck–Quick Step), who won the second stage in Nice on Specialized Turbo Cotton tires. It’s true that in terms of rolling resistance and aerodynamics, tires have long since surpassed tubulars. This drag can account for up to 20% of the energy you put out during a ride, and it’s certainly worth paying attention to when performance is the goal. At 30 km/h, there can be a difference of up to 15 watts in rolling resistance between the best tires on the market and the worst. From an aerodynamic standpoint, the tire’s shape in relation to the rim also offers an advantage over the tubular profile and the drag it creates at the wheel junction. Tubulars still have one clear advantage in racing: they let you keep rolling for a short time after a flat while you wait for help, something that’s nearly impossible with a clincher.

Now, the choice of tires is no longer solely a matter of safety or practicality, but also a question of performance, as is the case here with the Specialized Turbo Cotton tires, which pair perfectly with the Roval Rapide CLX wheels recently unveiled by the American brand—and which we’ll discuss in detail very soon.

Specialized is no slouch when it comes to its tire lineup, starting with the S-Works Turbo RapidAir tubeless tires, which are quite comparable to the Turbo Cotton, but also offers a wide selection ranging from durable training tyres to the S-Works Turbo, often praised for their balance of performance and durability. But thanks to their color (the famous beige sidewalls that add a certain flair to any bike), their slim profile, and the road feel they promise, the Turbo Cotton tires stand apart—a fact confirmed on the road even after several hundred kilometers.

Weight and Dimensions Available in three different sizes—700×24, 700×26, and 700×28—they’re still within standard weight ranges. Our two 26 mm samples weigh 236 and 238 g, so they are slightly heavier than the lightest models on the market. At roughly the same width, they give away, for example, about 15 grams to the Continental GP 5000, which nevertheless have a thicker tread and are therefore more durable.

They also weigh the same as the Veloflex Corsa Evo TLR, which are models supposedly designed for endurance riding and, most importantly, are Tubeless Ready.

When mounted on wheels with an internal width of 21 mm, the tires actually measure 28.5 mm wide (for a 26 section) and 24 mm tall. On Roval Rapide CLX wheels—whose front rim is very wide on the outside—the tire stays narrower than the rim, which is a definite advantage in terms of aerodynamic drag. For narrower wheels, the 24 section is undoubtedly recommended, while the 28 section is really best reserved for those who prioritize even greater comfort. And yet, there’s already no shortage of comfort with our test setup, partly thanks to the very wide U-shaped opening where the tire meets the rim, which allows for slightly lower tire pressure without any sagging of the sidewalls or loss of precision when cornering. In 700×26, there’s no need to inflate beyond 7 bar, and 6 bar is more than enough for a rider weighing less than 60 kg, without any loss of performance. Design

The polycotton casing is very flexible and high-density at 320 TPI (threads per inch), with a tread made of a compound called Gripton, a smooth, thin tread (barely over 2 mm), and shoulders featuring diamond-shaped lugs.

Underneath the tread is a puncture-resistant reinforcement called BlackBelt, which, despite the tires’ thinness and flexibility, seems relatively effective. The main concern is the fragility of the cotton sidewalls, which could prove particularly susceptible to cuts or abrasion. Installation isn’t very difficult, but it also depends on the rims and the shape of the beads. Mounting on Roval rims is made easier by their internal width, but it still requires a steady hand, and you get the feeling that the tire won’t come off the rim easily in the event of a flat.

Finally, tires like these deserve to be mounted with lightweight inner tubes, such as Specialized’s “Light” models (70 g versus 100 g for a basic inner tube), or even latex tubes to gain just a bit more in comfort and efficiency, since disc brakes finally allow the combination of carbon wheels and this type of inner tube without the risk of bursting due to the heat generated by braking on the rims. So don’t skimp on this—it would be a shame! Exceptional Performance From the very first few hundred meters, we were struck by the comfort and road feel of the Turbo Cotton tires. To be honest, this isn’t the first time we’ve ridden with them—these tires aren’t exactly new. However, this is our first time trying the 26-mm width, and the difference is truly noticeable compared to most tires on the market, even high-end ones.

Any slight weight disadvantage compared with the competition is completely negligible, as we’re immediately won over by the comfort and responsiveness these tires offer. The road feel is smooth, and on the rough asphalt of a country road, you feel fewer vibrations and, above all, better traction than with more common models. Of course, tire pressure plays a key role here: at 6 bar, it feels as though your regular bike has moved up a category to join the ranks of “comfortable” bikes, and at 7 bar it feels a bit firmer under you, and above all, you hear a sound comparable to that of the good old tubular tyres of yesteryear, with a characteristic whistle as you pick up speed.

The contact with the road is smooth, and on the gritty asphalt of a country road, you feel fewer vibrations and, above all, better traction than with more common models.

But it’s not just about the feel—the Turbo Cotton tires are very fast, with some of the lowest rolling resistance on the market, on par with dedicated time-trial tires, which are lighter and more fragile, according to bicyclerollingresistance.com. Grip is excellent thanks to the quality of the rubber, the flexibility of the casing, and the shoulder tread patterns. On dry surfaces, you’ll find yourself taking corners aggressively, and in the event of a downpour, you’re never caught off guard by unexpected loss of traction. Braking with disc brakes—even in an emergency—also shows that the tire maintains good contact with the pavement, delaying the critical moment when the wheel locks up, which could cause you to lose control of the bike. All of this takes place in mild or summer temperatures, so with fairly warm pavement. Performance might be slightly different on cold pavement—as is sometimes the case with certain rubber compounds—but we weren’t able to test this.

In terms of wear, the Turbo Cotton tyres still have a soft compound and are therefore susceptible to abrasion. After 2,500 km, we’ve noticed few cuts, but uniform wear across the tread, which inevitably reduces its thickness. Durability depends on the type of road you’re riding on; smooth, well-maintained asphalt is, of course, less abrasive. And paradoxically, even though they’re more comfortable than most other tires on rough roads, you tend to avoid those roads—at least if they’re littered with potholes or gravel. As a result, you should expect their lifespan to be about half that of the GP5000 or Michelin Power Road tires, for example, and given the price of the Turbo Cotton, this might give frequent riders pause.

As for the famous beige sidewalls, it’s worth noting that they’re much less prone to getting dirty with disc brakes than with rim brakes. This makes sense: even in the rain, there’s no longer any brake pad debris from braking, and a quick wipe of the sidewalls with a cloth and a little degreaser makes them look brand new again.

Ultimately, even if they aren’t exactly a new product, the Specialized Turbo Cotton tires prove that they are exceptional models—and among the best-performing on the market today—whether in terms of low rolling resistance, responsiveness, traction, or comfort. Of course, all these qualities come at a high price and with durability that falls short compared to some other models on the market.

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