Pirelli P Zero Tubeless Review: Before I was ever a bike guy, I was a car guy. I’m talking from when I was a kid in grade school. And the cars I’ve always loved most were Formula One or Grand Prix cars (I can still remember going to see the movie Grand Prix in the theater for a friend’s birthday party). They represent the pinnacle of motorsport. Fans of modern Formula One (F1 for short) know that the Pirelli P Zero is the official tire used by all the teams. The P Zero moniker is also used for Pirelli’s top of the line of clincher bicycle tires. Just as F1 tires come in different compounds for different track and weather conditions, the P Zero Velo tires come in different flavors:
- P Zero Velo is an all-around race tire
- P Zero Velo TT is a “go fast” tire that places a premium on low rolling resistance and aero drag
- P Zero Velo 4S is a wet/cold weather tire with high puncture resistance
Now, Pirelli has upped the ante on the P Zero Velo lineup with the introduction of the P Zero Velo Race TLR tubeless tire.
PEZ readers probably know that I was seduced by the Dark Side and went tubeless last November. I readily admit that I was previously skeptical about the benefits of road tubeless (“a solution in search of a problem” is one phrase I used), but I’m since a convert. The Pirelli Cinturatos I originally mounted on Irwin AON TLR wheels just before Thanksgiving were good until almost Memorial Day (nearly 3,000 miles!) What was truly impressive (and one of the reasons I’m sold on road tubeless) is that I rode the last 300-400 miles with a zillion (OK, maybe not that many — but a lot nonetheless) little “micro” cuts in both the front and rear tires. Any one of those cuts would likely have been a flat tire riding clinchers with tubes. But I survived them riding tubeless.
All of Pirelli’s motorsports experience is applied to their bicycle tires
Those Cinturatos were subsequently replaced with another pair of Cinturatos, which are still perfectly good. But I wasn’t going to wait until they wore out to have a go on the tubeless P Zeros. One of the reasons my first pair of Cinturatos lasted so long is because they’re more of an “endurance” tire designed for puncture resistance and high mileage. In terms of construction, they’re probably on the “beefy” side for a road tire since they’re designed to withstand the rigors of gravel riding. But when Pirelli offered up the opportunity to ride a pair of “go fast” tubeless tires, it was an offer I couldn’t refuse. As a road tubeless convert, I wanted to see what riding tubeless would be like on a set of tires that are all about minimizing rolling resistance and going fast (even if I’m not so fast these days). So even though it’s a bit of a hassle and mess to change out tubeless tires, I’m now rolling on the P Zero Race TLR tubeless tires.
Here’s what Pirelli has to say about the P Zero Race TLR tires:
- Developed in collaboration with two World Tour teams, the Mitchelton-SCOTT of the reigning RR world champion Annemiek Van Vleuten and the Trek-Segafredo of the reigning RR world champion Mads Pedersen and of Vincenzo Nibali, the new P Zero Race TLR tires can call themselves World Tour Ready tires.
- P Zero Race TLR is an all-around tire, ideal in competition as well as in training. It’s almost a four-season tire, with a TLR casing reinforced by Pirelli TechWALL+ technology. It offers excellent grip, high smoothness and, above all, great puncture protection, at a low weight.
The TechWALL+ provides multiple layers of puncture protection. Based on cutaway pictures on Pirelli’s website, the two innermost layers are bead-to-bead (you would expect that in a tubeless tires for sidewall protection). The Cinturato uses a nylon belt, but Pirelli doesn’t specify the material for the P Zero Race TLR. There is an additional layer underneath the tread (the Cinturato uses an aramid fiber belt, but Pirelli doesn’t say if that’s what they use for the P Zero Race TLR).
Speaking of weight, Pirelli claims the P Zero Race TLR in 700×28 (what they sent to PEZ — other sizes are 700×24, 700×26, and 700×30) weigh 295 grams. Mine was slightly overweight at 299 grams. If you want to go even lighter, Pirelli also make a P Zero Race TLR SL tire that weighs 20 grams less (for 700×28). But you’ll lose a layer of puncture protection under the tread for that 20 grams.
Subtract 5 grams for the fancy rubber band around the tire
The tire compound is what Pirelli calls SmartEVO that is an evolution of its SmartNET technology used in the Cinturatos I was riding previously. Presumably, SmartEVO is faster and grippier. To the touch, the P Zero Race TLR rubber feels marginally softer than the Cinturato.
Siping is supposed to channel away water for better grip in the wet, but I don’t really know how much of a difference it makes with bicycle tires. I do know that the little dimple is a tire wear indicator.
The casing of the P Zero Race TLR is 120 tpi, which is more supple than the 60 tpi of the Cinturato. More supple usually means a smoother, more comfortable ride.
All these comparisons to the Cinturato are meant to provide an indicator of how different a tire the P Zero is. Whereas the Cinturato is more of an endurance/all-season tire (as well as able to withstand the rigors of gravel — I’m not a gravel grinder, but can attest that the Cinturatos have held their own on extended non-asphalt stretches of road that I’ve ridden), the P Zero is definitely more of a fast training/race tire with the emphasis on low rolling resistance and grip.
There is no such thing as a “do everything well” tire, so going fast comes at some expense to tire protection and wear
Mounting the tires
Installing tubeless tires is fairly straightforward — essentially the same as clinchers but without having to insert a tube. The Pirelli P Zeros went on my rims relatively easily, but I still had to use tire levers to get the last bit of bead up and over the rim. (Pro tip: Spray a mixture of soapy water on the tire bead and rim to help get the tire mounted and it will also help get the tire seated on the rim.) As I noted in my previous PEZ article about going road tubeless:
I know this seems obvious but … If you’re going to use a tire lever to install a tire on a carbon rim, make sure the tire lever is a sturdy plastic/resin material and not metal. And I wouldn’t use a “cheap” tire lever. I’ve actually broken tire levers trying to get a tire with a super tight bead onto a rim.
Faites attention! The P Zeros are directional, so make sure you don’t put them on backwards!
One thing that was different this time around for me is that I didn’t take my wheels to my LBS to have them seat the beads with a tire compressor. Instead, I used a Canister Thingamajig (yes, that’s a technical term) that you pressurize using a floor pump and then release the air in the canister to seat the beads. If you’re going road tubeless and don’t already have a compressor, this is a worthwhile investment (assuming you already have a quality floor pump — if not, there are floor pumps with a built-in canister).
(1) Make sure the canister is fully empty. (2) Close the valve. (3) Attach the hose from the canister to the valve stem (requires removing the valve core). (4) Attach the floor pump hose to the canister. (5) Pump to 160 psi. (6) Open the valve to release the air into the tire to seat it. Voila!
Once the tires were seated, I injected sealant. I’m a fan of Effetto Mariposa Caffelatex sealant because I like that it “foams up” when agitated (like the spinning of the wheel) and is supposed to coat the inside of the tire more thoroughly — especially the sidewalls. After at rest for a while, it returns to its liquid state.
Pumped up to max pressure (101 psi/7 bar), the 700×28 P Zeros (mounted on my AON TLR38 wheels that are 25 mm external width and 18 mm internal width) measured exactly 28 mm wide. If being aero and making every watt count was of paramount importance for me (it’s not), I’d go with 700×26 so that the tires would be flush with the rims.
The Effetto Mariposa app specs 35 mL of sealant for 28mm tires
I was pleasantly surprised that I could pump up the tires without any sealant leaking between the tire and rim (which is perfectly normal as it’s filling any minuscule gaps that need to be sealed — just wipe away the excess). Once I was sure everything was copacetic and the tires were holding air with the sealant (make sure you really spin your wheels so sealant can coat the inside of the tires), I pumped them up to Pirelli’s maximum recommended pressure of 101 psi/7 bar and let them sit overnight. (BTW, expect to lose a few psi overnight, which is fairly normal with tubeless tires.) The next morning, I pumped them up to my desired pressures for riding. Pirelli recommends 75 psi for a rider of my weight (~60 kg), but based on my experience riding the Cinturatos tubeless, I decided on 72 psi for the rear and 70 psi for the front as my starting point.
I ride slightly lower tire pressures than what Pirelli recommends for my weight
A piece of Gorilla tape to protect my carbon rim from the valve stem nut
Of course, the most important thing is to make sure the manufacturer logo is centered over the valve stem for the EuroPro touch and make people think you’re riding tubulars
But how do they ride?
PEZ readers will know that I was immediately smitten when I switched from riding Pirelli’s Cinturatos with tubes to tubeless:
As this is written, I have just over 100 miles riding tubeless but I’m already sold on them. Not for their flat prevention (fingers crossed that I actually wear them out without flatting), but for their ride quality. I had previously ridden Pirelli Cinturatos with tubes since this June (about 2,600 miles). The difference riding them tubeless is nothing short of remarkable. It’s about as close to the ever elusive feeling of riding tubulars (what I used to ride exclusively way back in the day when I was still racing). The best way I can describe the ride is that it’s a sensation of floating on the tarmac.
My first ride on the P Zero Race TLRs was a 30-something miler just to shake them out over a variety of road surfaces. My initial impression can be summed up fairly succinctly … WOW! If I was smitten by the Cinturatos, I’m head over heels with the P Zero Race TLRs.
I don’t have any way to measure rolling resistance, but my seat-of-the-pants (or is that chamois?) meter tells me that the P Zero Race TLRs roll faster than my previous Cinturatos. Of course, I expected that (and would have been surprised — as well as disappointed — if the P Zeros didn’t feel faster). On streets in my neighborhood that I ride regularly warming up before and cooling down after rides, I found myself rolling faster without making a concerted effort to go fast.
I intentionally rode over as many road imperfections that I could find (not hard to do) — stuff like seams/cracks in the pavement, manhole covers, dips and bumps, uneven and broken up sections of pavement (just not potholes). The combination of wider tires and lower tire pressure made the hits less harsh and much softer — in some cases almost to the point where you didn’t really notice (or at least where they weren’t a bother). If you ride on a lot of chip seal roads, you’ll love the P Zero Race TLRs.
My riding also took me over some sections of bike path where tree roots have pushed up the pavement. You could definitely feel it, but it didn’t feel like you were getting bounced around as much. I could ride faster and never felt like I would get bounced off.
Another test of the tires was riding on wood boardwalk that creates a washboard-like effect with lots of road chatter. You could feel the constant vibration, but it was muted.
On the boardwalk (not under it as The Drifters sang)
And then there was some riding on cobbles at speed. The Pirelli P Zero Race TLRs really took the edge off. The best way to describe how it felt was like a dull buzz. The irony was that I really felt in contact with the road surface in terms of grip but didn’t feel the harshness of the road surface to the extent you would expect (it’s worth noting that I ride without gloves and my hands didn’t feel like they were getting jarred). Admittedly, these were “small” cobbles but the P Zero Race TLRs were confidence inspiring.
Not Roubaix and not Flanders, but cobbles nonetheless
Across all these varied road surfaces, the one word I would use to describe how the Pirelli P Zero TLRs ride is “composed.”
The benefit of all that comfort that wider tubeless tires afford at lower tire pressures is increased control. You don’t get bounced around as much. You’re not fighting to keep yourself balanced on the bike. You’re not having to hold onto the handlebars as tightly. Not only is it less physically demanding, but also less mental stress. And all that also translates into being able to ride faster.
Of course, where the Pirelli P Zero Race TLRs really shine is on smooth tarmac. They come up to speed quickly and roll super smoothly. Plush is a word that comes to mind. And I’ll double down on my previous description of tubeless tires having the “sensation of floating on the tarmac.” Another way to describe them is that they seem to glide effortlessly (OK, maybe not effortlessly — but with seemingly less apparent effort).
One silver lining to COVID is that a lot of streets in my part of the world have been recently re-paved and are now smooth ribbons of asphalt
If my first ride on the Pirelli P Zero Race TLRs was about seeing how they would ride on different road surfaces, subsequent rides (I now have over 200 miles on the P Zeros) have been more about seeing how they handle. I wish I could say I’ve taken them down twisty mountain descents at breakneck speeds, but alas … not. Such riding isn’t readily convenient — especially within the time constraints of getting this review written. But the Blue Ridge Mountains are within reasonable enough reach as an all-day affair and I hope to get there before the end of the warm weather riding season.
One of the first things I did was some parking lot riding where I could weave/snake around doing moderate speed left-right and right-left transitions, as well as U-turns. This provided some chamois/butt feedback on the grip of the P Zeros. It also let me know how easily/quickly I could flick them into a corner.
After that, I did my best to find as many fast corners (including downhill corners) as possible. The combination of wider tires and lower tire pressures means more contact patch area and the Pirelli P Zero Race TLRs felt planted cornering. So much so that I often found myself approaching corners with a motorcycling (from my days riding supersport sportbikes on the street and track) mindset (but without throttle control): choosing my line and apex point, adjusting my position in the saddle, inside shoulder down, inside pedal knee out, setting my entry speed, and then just getting my bicycle leaned over and letting it flow through the corner at speed.
I also have within easy riding distance some sections of downhill road with S-like bends and even hairpin turns. The Pirelli P Zero TLRs handled these with aplomb. At comfortably fast entry speeds (and I felt like I didn’t have to scrub off as much speed), they felt secure leaned over and transitioning from one edge to the other. And I’m pretty certain I wasn’t anywhere near approaching the limits of the tires (but discretion being the better part of valor, I wasn’t going to push them hard enough to find out).
In summary, I found the P Zeros to be fast, comfortable, and grippy. What’s not to like, eh?
Of course, what I can’t comment on is tire wear and puncture protection. I fully expect that I won’t get as many miles riding the P Zero Race TLRs as I did the Cinturatos (and I may switch back to the Cinturatos in the late fall for cold/wet weather riding since they’re better suited to those conditions). And we’ll just have to see how well the P Zeros ward off punctures. I know they’re not as robust as the Cinturatos, but … fingers crossed.
Once you go tubeless, you never go back
PEZ readers already know I’m sold on road tubeless. Never say never, but I’m never going back to clinchers. Or at least I’m not riding clinchers unless I absolutely have to.
As much as I loved riding the Pirelli Cinturatos tubeless, I’m loving the Pirelli P Zero Race TLRs even more. They’re definitely tires that emphasize performance/speed. Even though I’m no longer racing or training for anything (I just ride to ride and to be in the company of my riding buddies), who doesn’t want to ride faster? From a ride quality standpoint, they are a step (maybe two) up — so both smoother and faster. I just have to remember that no matter how good they are, I can’t ride them like this:
California Superbike School at Virginia International Raceway
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