Pirelli has released the P Zero Race 4S, a new tyre said to combine a “racing feeling” with the durability to be used all year round.
The P Zero Race 4S takes the place of the P Zero Velo 4S in Pirelli’s range of winter road bike tyres, and the brand says it has improved durability, smoothness and reliability while featuring a new casing design adapted for wider rims.
The tyre is the first to be made in Pirelli’s new factory, the renovated Bollate plant 10km from the brand’s Milan Bicocca headquarters. This also means it is the first tyre to be made entirely in Italy since Pirelli returned to the cycling market in 2017.
Pirelli says the tyre is currently available in 700x26c and 700x28c in a clincher version, with more sizes and a tubeless tyre option available later in the year.
The P Zero Race 4S costs £61.99 / $84.90 / AU$109.99 / €69.90.
Summer compound, winter tyre
Despite being a four-season road bike tyre, the P Zero Race 4S uses the same SmartEVO proprietary rubber compound as Pirelli's P Zero Race and P Zero SL tyres. This compound has been tested by Pirelli’s WorldTour teams UAE Team Emirates and AG2R Citroën.
Pirelli says this compound is designed to deliver “high levels of performance in terms of grip, conditions of use, rolling resistance and reactivity”, though any data supporting these claims hasn’t been provided.
The use of this compound is at the core of Pirelli’s claim that these tyres provide a race feeling, but Pirelli has had to employ a number of features to make the P Zero Race 4S suitable for riding through winter.
Most notably, Pirelli has worked to develop a tread pattern to improve grip on slippery or uneven surfaces. The P Zero Race 4S has siping cut into the rubber, which its summer tyres do not.
This helps with water dispersion, but Pirelli claims that more important than this is the fact the siping decreases the amount of time it takes the tyre to warm up.
In turn, this means the P Zero Race 4S – and specifically the compound – can work effectively even in colder weather.
The thickness of the rubber compound is greater than its summer tyres to provide extra protection and increase the potential mileage of the tyres.
Pirelli has put a nylon 'Techbelt' underneath the rubber compound to ensure greater puncture protection than its summer tyres. Pirelli says it chose to use nylon due to the material's flexibility.
Along with the siping and the tyre’s thickness, the nylon works to improve the contact patch of the tyre for greater grip.
Like Pirelli’s summer tyres, the P Zero Race 4S is said to be designed around a 19c rim width, following the trend for wider internal rim widths on road bike wheels. Consequently, each size has a wider footprint, which improves puncture protection and cornering control, according to Pirelli.
Pirelli says these changes make the P Zero Race 4S a “little less responsive” than the P Zero Race.
Made in Italy
Pirelli’s new Bollate factory on the outskirts of Milan started life as a car manufacturing plant, which opened in 1963.
The plant has been converted to support the production of Pirelli's “high-performance products”, and the factory is expected to be fully operational in 2023, with the production facilities growing over the next year, as well as aesthetic work being undertaken.
The brand has 18 factories around the world to support its production of bicycle and motorsport tyres.
Speaking to BikeRadar, Pirelli explained there are several reasons why producing products in Italy is a good idea.
Pirelli says many of its products are “90 per cent ours” because it develops the compounds in Italy but outsources production. By making the tyres in Italy, this percentage increases presumably to 100 per cent, as the brand oversees production and ensures quality control.
Furthermore, Pirelli says producing tyres in Italy allows it to develop better compounds than it would otherwise. It says that due to the difficulty of working with rubber, it has to make its formulas simpler when the production is more spread out and complicated.
Making tyres in Italy means Pirelli can therefore develop more complex, and consequently better-performing, compounds.
Having a factory only 20 minutes drive from its headquarters also means Pirelli can undertake product development more easily.
When producing tyres in factories on the other side of the world, any developments or adjustments made to the design of the tyres at Pirelli’s headquarters would result in long waits to see the results. However, having a factory up the road increases the speed at which Pirelli can tinker with its designs.
For an idea of the difference this makes, Pirelli says a tyre will typically go through roughly 100 different specifications, but the new P Zero Race 4S has gone through 600, with Pirelli making up to 12 changes a day over the course of a year.
The proximity of the Bollate factory to Pirelli’s headquarters in Milan does present some challenges. Tyre production is not particularly clean or pretty, with lots of heat, noise and dirt, and the resulting fumes would be nasty for the urban area around the factory.
To avoid this, Pirelli says the air coming out of the factory is cleaned in order not to subject the local residents to fumes laced with rubber dust.
Pirelli P Zero Race 4S specification, pricing and availability
The Pirelli P Zero Race 4S is available to buy now. Currently, it is only available as a 700x26mm or 700x28mm clincher. Pirelli says more sizes will be available later in the year, with a 700x30mm clincher in the pipeline. There will also be a tubeless tyre version available in widths up to 32mm.
Pirelli P Zero Race 4S clincher
- Available sizes: 700x26mm, 700x28mm
- Claimed weight: 240g (700x26mm), 260g (700x28mm)
- Casing (threads per inch): 120 TPI
- Colour: Black
- Pricing: £61.99 / $84.90 / AU$109.99 / €69.90
