I’m no stranger to wider tyres for commuting and Mountain Biking, but on the road bike with the higher speeds and aerodynamic demands, tradition has dictated narrow tyres. Over the past two decades this tradition is being gradually eroded and there is a slow creep to wider road cycling tyres. When Pirelli returned to bicycle tyre production in 2017, there were no 19mm or 21mm tyres, the P Zeros Velo’s were available in 23, 25 and 28mm widths.
In the 1980’s Pirelli disappeared completely from bicycle tyres production though historically have been connected with legendary and victorious riders. Event after a 30 year absence, the brand name has remained so well known through car tyres and association with performance and speed that it feels as though they were never gone. Part of successful reintroduction was being immediately adopted and distributed globally, it didn’t appear that they had the struggle of building up their network of distributers and dealers.
In selecting a tyre side for review, I decided to go all the way to the extreme and opted for the wide 28-622 clinchers. I assumed they would deliver increased comfort and handling over narrower tyres. I was also curious whether they would fast because new generations of wider rims paired with wider tyres tend to reveal better aerodynamic capabilities than narrow rims and tyres.
Modern day roads cyclists demand wide tyres, which Pirelli offer in the P Zero Velo range. But modern cyclists also want tubeless-ready tyres which these are not. In my case, this is not an issue as I am still happy to avoid sealant and have been able to easily swap them to other rims during the review. For some riders however this could be a deal-breaker. Tubeless has long since become a standard for Mountain Biking and as this ‘trend’ continues to makes its way into road cycling, riders tend to assume that new tyres and wheels will be tubeless ready.
Wider tyres come with a small weight penalty over thinner tyres, but again road cycling trends have moved beyond the weight-weenie era and Aero beats weight (to a certain degree). The P Zero’s in 28mm weigh 220 grams placing them at 30 grams lighter than Continental GP5000’s in 28mm. And at a retail price of around $69 in Australia, the P Zeros will also save you $20-30 per tyre off the cost of the GP5000’s.
Before diving into the tech and riding qualities, a few words on the other Pirelli bicycle tyres. In the P Zero range there is a TT model that has lower rolling resistance and the 4S model which is optimised for cooler temperatures and all-weather riding including wet weather. Earlier this year they released the Scorpion series of MTB tyres and this month Pirelli launched the Cinturato range of Gravel Tyres. There are urban tyres as well though these are not carried by the Australian distributor for Pirelli bicycle tyres.
Unpacking and Tyre tech
The packaging lends these tyres a stylish look compared to the competition and each tyre is neatly presented in a box with a black rubber band which reminds me of those yellow Livestrong wristbands that were in fashion a decade ago.
I had the standard versions which have P Zero Velo text and graphics printed in white on the sidewalls. For a few dollars extra, there are colour versions (in some sizes) with pink, red, yellow and anthracite if you want to match them to your wheels and bike.
The rubber compound used to mould the P Zeros is named SmartNET Silica and is a compound derived from their car and motorcycle expertise. The idea behind the SmartNET Silica is creating a fibrous network within the rubber that improves grip and puncture resistance but without limiting rolling resistance. An interesting detail is that Pirelli manufacture the rubber compound in Italy and ship it to their French manufacturing partner where the tyres are made.
Hidden beneath the surface of the tyre is a layer of Aramid fibers which forms synthetic barrier in the tyres called a ‘breaker’ which improves puncture resistance.
The tread is smooth (slick) though has indentations with a lightning both pattern on the edge. It is a cool feature and I assumed it serves to disperse water. I was on the right track though this wasn’t the whole story. Samuele Bressan from the Bicycle Division of Pirelli in Italy explained that these grooves help with grip and the tread pattern was designed so that edges warm up faster to improve grip while cornering.
Overall, the construction of the tyres are neat and tidy so it is time to get them on the bike and get going.
I tested the P Zeros on both a 50mm deep carbon wheelset as well as a 30mm deep aluminium wheelset and was able to install and remove the tyres without tyre levers. Sometimes this approach requires a little more massaging however this is my preferred approach. I also continue to massage it while inflating to ensure the tube and tyres are correctly and evenly seated.
Fitting the Pirelli’s on carbon rims, I got one nice ‘pop’ for one tyre during inflation to let me know that the bead was properly seated while on the other carbon rim and on the Aluminium rims, there was a noticeable stretching and settling into place. My target tyre pressure is 100psi (6.8 bar) though after inflating I feel that these could comfortably be set at 90psi (6.2 bar).
Inflated, I measured the 28mm wide tyres with vernier calipers and I recorded an actual width of 30mm. On my comparatively narrow carbon fiber wheels (with an outside width of 24mm) the P Zeros looked pretty bulbous. The aluminium rims I used in comparison have an outside diameter of 27mm and the tyres appeared to have a more natural fit. When fitted, I could see that the P Zeros appear to have a more rounded and less angular profile than other road tyre brands.
The spews are numerous and long… Spews are the tiny hairs on rubber wheels and these play an important part of the moulding process to ensure that the rubber is properly distributed. I will explain the ‘issue’ I encountered with these spews a little later.
Before you can start to ride, you first have to get the wheels with the fresh tyres onto the bike. If you have disc brakes… then you will be ready to roll in no time. If you have rim brakes, to have to get these wide tyres past the brakes first. Even with the rim brakes released, I found it was too narrow to slip the wheels on. I released some slack in the cable and adjusted then brakes allowing me to now squeeze the tyres through and into place… Depending on the width of your rims compared to tyres, there may be no quick wheel changes. A tip is to release the air from the tyres and simply pump up the tyres are the wheels are on the bicycle. You should also check to ensure that you have enough tyre clearance on your bike frame to be able to fit the 28mm, for most road bikes however, it shouldn’t be an issue.
From the first ride I also noticed that the P Zeros 28-662 tyres felt grippy and comfortable, particularly when turning and riding through curves. While testing these tyres I never felt as though I was pushing to close to the limits and could comfortably and confidently reach downhill speeds of 75kmh. The more I rode, the further I could lean into the curves.
100psi with the wide, grippy tyres delivered confidence on smooth hotmix surfaces as well as rough and crackling bitumen. Sticks, gravel, patches of sand and debris on the roads and sealed paths were all easily overcome. I also had the chance to ride in wetter conditions, not pouring rain but wet roads and puddles and felt happy with the handing and grip. I naturally moderate my speed in poor wetter conditions but recognised that the grip was also reliable across changing conditions. Both the carbon wheelset and aluminium wheelset I used with the P Zeros mounted each have their own traits but didn’t feel that the tyres behaved differently.
In contrast to the grip and comfort, from the first ride, the P Zeros gave me the feeling of being a little slower. My ride data was still fairly ok and testing over a few months meant that I could filter through good-days and bad-days but overall they didn’t feel quite as speedy as my regular GP4000’s (with innertubes). A likely contributing factor is that my 50mm deep carbon wheels are a bit narrow so are not perfectly coupled, I would expect current generation wide and aerodynamic carbon fiber wheelset would be a better match if competitive performance was important. But also the narrower 23mm and 25mm tyres would be lighter and better coupled to my current rims so would be more suitable for criteriums.
I feel the 28mm are at home for longer distance rides such as Gran Fondo and Audax rides where the pace can be more relaxed and comfort and handling takes priority.
What’s that noise?
I appreciate a completely silent road bike and immediately recognise noises, typically it is a dirty drivetrain or something with the gears. When I put the P Zero’s on I got a constant whirring hum when I rode. One of the traits that Pirelli promote is a low road-noise but they were far from quiet.
It wasn’t at all difficult to identify the culprit, the hairy rubber spews from the tyre were touching the frame as the wheels spun both at the rear wheel near the bottom bracket and on the front fork. Blackened rubber stripes appeared on the frame from the spews and it wasn’t long until I was fed-up with the noise and the extra cleaning duties.
Attacking bike tyres with scissors is usually something I do after the tyres are worn-out and I want to look inside. So with care, I gave the Pirelli P Zeros a haircut. Front and back with neatly trimmed hairs for that freshly shaven look.
No more noise, no more marks. Bikes that already have a lot of clearance, especially road bikes that are edging into cyclocross and gravel territory may not face this at all. Trimming was an extra and necessary step for but it is easily remedied so is not a big criticism.
The grippy P Zero tyres work well in dry and wet conditions. On rougher surfaces with sand or debris, even when I was caught momentarily unaware, I felt in-control. Chasing the KOMs, the P Zero Velo tyres in 28mm felt slower compared to my narrower 25mm GP4000s. For more competitive performance with the Pirellis’, pairing with the right aero-carbon wheels and scaling back to the 23mm or 25mm would make sense.
The comfort level in these tyres will depends on the tyre pressure and at 100psi (6.8 bar) the micro-vibrations are nicely absorbed by the tyres, wheels and bike. A lower pressure of 90psi (6.2 bar) will increase comfort even further. Longer distance riders who want good handling and grip plus suitability for varied road surfaces and weather conditions will be well served by the 28mm Pirelli P Zero’s. The retail price as well as the weight saving is more attractive than the Continental GP5000’s though at a cost of a speed.
Pirelli Tyres are distributed in Australia by FE Sports and are available in bike shops across the country.