We test the Pirelli Scorpion Trail and Enduro tyres. Picking the right tyre just got a whole lot easier!
Pirelli have been working with rubber for nearly 150 years, so when the Italian giant turned their attention to bicycle tyre manufacturing, it's certainly not by halves.
With PZero, Pirelli cater for the premium road going vehicles, Formula 1 and now road bikes while the Scorpion range will be familiar with those whom follow Motocross, Enduro or the coveted Dakar.
With over 460 championship wins across motorsport disciplines, the Italians sure do know a thing or two about rubber, and how to blend a wining compound. Pirelli launched their Scorpion mountain bike tyres in early 2019, and we've covered the concept after the media release on the slopes of Mt Etna. The range is much larger and now we've had the opportunity to test their Trail and Enduro range here at home in Australia.
Ben and I have been sent a range of Scorpion Trail and Scorpion Enduro tyres for this review from FE Sports, the Australian importers. The Pirelli Scorpion Trail tyres come in 2.4 inch and the Enduro in predominantly 2.6 inch along with a 2.4 inch options. Each range is available in 29" and 27.5".
Immediately it's easy to see these are high quality, with perfectly aligned graphics and tread that spins true when mounted. The tyres measure true to their size when inflated on the 30mm internal width rims they are designed for. Looking closely at the tread patterns, they are more complex in design than many of us may be used to and clearly show that Pirelli are serious about offering something high end.
Along with the Rear specific models, Pirelli have a tyre for Soft conditions, Mixed conditions, or Hard conditions. Their concept is that their single compound SmartGrip rubber provides the chemical grip you need, and selecting the right tread creates the mechanical grip.
The Soft conditions tyre has tall and aggressive tread knobs to pierce into soft terrain like loam, soft sand, wet soil and loose dirt.
Mixed conditions is a little less aggressive with a greater spread of tread knobs, aiming to cover the broadest range of conditions while still not giving up too much in terms of rolling speed.
The Hard conditions tread pattern has a lower and tighter spread yet again, to really be very fast rolling. There is no Hard conditions options for the Enduro casing, or in the eMTB range.
Comparing a Trail Soft model to an Enduro Soft tyre you can also see that the tread is deeper and more aggressive on the Enduro model - but the differences between the Trail and Enduro range runs deeper than that.
Pirelli Scorpion Trail tyres use their ProWall casing. The ProWall casing has sidewall reinforcement to increase puncture protection and improve handling at low pressure - which is something Pirelli do recommend trying. In addition to the regular 60tpi casing a layer of nylon fabric is applied over the casing sidewall for extra protection and improvement in cornering stability.
Pirelli's Scorpion Enduro range features the HardWall casing. This has extra bead to bead protection with an additional rubber insert directly above the bead for extra reliability and strength for aggressive riding styles. HardWall was developed for Enduro racing specifically, and these reinforcements embedded in the casing improve structural reliability as well as providing more supple support at lower pressures.
Sitting a Scorpion Trail (ProWall) and a Scorpion Enduro (HardWall) tyre side by side, both of them are equally stiff enough to hold the tyre up under its own weight. Most tyres from other brands tend to just flop over. This doesn't make the Trail tyres or Enduro tyres harder to fit, it just shows that the construction of the tyre isn't just marketing speak – they really are incredibly reinforced for their respective uses.
All the tyres we received weighed just about spot on the claimed weights. A 29x2.4 inch ProWall Scorpion Trail Soft terrain weighed 950g, while the Enduro 29x2.4 inch Soft terrain with HardWall weighed 1020g. Some early Enduro models featured a casing that had even more reinforcement up the sidewall, and it has become the HyperWall eMTB casing. We had one on hand, and a 29 x 2.6 inch Soft terrain tyre came in at 1330g. Its a simple message for riders, ProWall is tough, HardWall is tougher and HyperWall is really very tough!
Setup was a simple affair, we were mounting our Pirellis up onto Bontrager's new Line Pro and Elite 30 Carbon wheels which have an internal width of 29mm which is the sweet spot for both Trail and Enduro disciplines. Mounting the tyres dry and without sealant on the TLR (tubeless ready) rims they sealed without the need for sealant. We then installed a good 100ml of Ride Mechanic's Hoop Goop in each.
It is worth noting that Bontrager use a neat plastic “TLR” strip which makes fitting tight but means that a track pump can be used you have a seal almost 100% guaranteed.
On the Trail
It has been super wet on our local trails lately, uncharacteristically wet and mild which made the initial tyre selection pretty easy. Both Ben and I mounted up Soft Terrain tyres on the front and Rear specific tyres on the rear. I was using the Trail casing 2.4” tyres on my Forbidden Druid, while Ben was running the 2.6” Enduro tyres on the 2021 Trek Slash.
When comparing the Trail to Enduro tyres, the first impressions show that the HardWall casing in the Enduro tyres really does give the tyre a stiffer feel than the pressure might suggest and it therefore doesn't tend to wander around under you in turns.
Talking directly with Pirelli in Italy, they recommend to run lower pressures than you would normally use in other brands of tyres due to the incredibly stiff sidewalls and the way that they've made their tyres to be more supple over the terrain.
While we started off using our regular tyre pressures we did have to drop tyre pressures in order to maintain the grip that we were chasing. The Scorpions really do have incredible support via the sidewalls.
Ben's take on the Scorpion Enduro range
The Scorpion Enduro range has three tread options, with a Rear specific, plus the Soft conditions and Mixed conditions tyre. They come in 27.5” and 29” sizes, and in 2.4” and 2.6”, all using the HardWall casing.
The Scorpion Rear specific tyre has a tread pattern that was developed for use on the same wide range of trails as a Scorpion Mixed but with faster rolling and better braking. Being a specific design for the rear Pirelli pulled on their experience in the world of motocross to help increases grip and stability when braking and accelerating in a mixture of terrains and conditions.
The Scorpion Rear is an extremely fast rolling tyre and at first look the rubber does feel quite firm. I didn't see any real signs of wear on it but once dropping the pressures and getting used to the tyre it was really confidence inspiring. The Scorpion Rear features the same single compound as the Scorpion Soft and Mixed and the same casing.
You can use the Soft or Mixed conditions tyres on the rear if you think they're better suited to the conditions you're riding in – but Pirelli have made the Rear to optimise braking and acceleration while also rolling as fast as possible.
The Scorpion Enduro Soft tread pattern is made up of deep, widely spaced knobs that bite into the terrain to provide maximum levels of grip in soft and loose dirt - much like a cut down spike. The height and rigidity of the tread help to guarantee traction and braking on steeper trails as well as excellent support when cornering. The knob spacing of the Scorpion Enduro Soft tread pattern also helps to shed mud in these conditions.
It must be said that the Scorpion Mixed is the most versatile tread in the Pirelli range and in fact of all the models of tyres that we tested the Scorpion Mixed was the favourite. The Scorpion Mixed has a slightly lower tread pattern than you find on the Soft conditions tyre, but a slightly higher tread than you find on the Rear specific.
The shape of the knobs and tread layout certainly does offer grip in a wide range of conditions and it's probably going to be your go to tyre in this range, be it a 2.4 inch or a 2.6 inch. In the Enduro casing (HardWall) I did end up running the Scorpion Mixed on both front and rear as well as using it as a rear with a Scorpion Soft on the front. I found that the Scorpion Mixed on the rear was a real favourite in the conditions we had through the testing period.
Ryan's take on the Scorpion Trail
I opted for a Scorpion Rear specific and a Scorpion Mixed on the front and played around with pressures to find a point where the tyre was holding without deforming or hitting the rim too frequently. It took a few attempts to get this right as the casings are more robust than other manufacturers and provide more sidewall support while retaining a supple ride feel.
Both tyres certainly roll much better than what I was otherwise running on my bike, partially due to a 150g saving on the rear and roughly 100g on the front. But the main difference is the slight reduction in tread height and the profile of the knob on the Scorpion Trail tyres. The Pirelli Scorpion tread is less square and the knobs are much more tapered, so the mud and debris isn’t sticking to it as much. The compound does feel harder than I am used to but on wet rock the SmartGrip compound doesn't glance too much and tracks pretty well. This is despite hitting wet rock on an angle with dirt and mud covered tyres, which is often the downfall of tyres. Trying to take a compound reading was pointless on the trail as a Shore A durometer is pretty inaccurate on a mounted pneumatic tyre as the casing deforms when trying to get a reading.
The Scorpion Soft terrain is obviously the most aggressive pattern with huge 8mm proud side knobs and 6mm tall design of central knobs designed to bight into “soft terrain”. The addition of knobs compared to the Mixed terrain I had mounted on the front previously made a big difference to the mechanical grip of the tyre over the Soft terrain as it had more knob edges. Same trail, maybe 45 minutes later and the difference was noticeable.
In the wet and soft soil the Scorpion Soft and Scorpion Rear specific tyres were exceptional. But one of the tyres that may not gain a lot of exposure but should definitely be looked at in the Scorpion Trail range is the Scorpion Hard conditions tyre. The tread pattern of the Scorpion Hard is made up of low, densely packed knobs with reduced height to increase speed and limit deforming when cornering on hardpack terrain.
By mixing the Scorpion Hard on the rear with Mixed on the front I had a very, very fast combination allowing grip on the loose hardpack surface of Stromlo. I was absolutely flying in certain areas and would definitely look at this setup for racing, depending on the trail conditions as long as you did not require a lot of heavy breaking on steep loose terrain.
Again after some solid rides, little to no tyre wear was visible front or rear yet the Soft and Mixed terrain tyres felt softer than the rear but all had SmartGrip, it was time to reach out to Pirelli and workout what it all meant. Was it the same compound across all models? And why don't they use multiple compounds in one tyre like other tyre brands?
Zooming with Pirelli
We reached out to Samuele Bressan, Pirelli’s Bike Divisions Head of Marketing and were met with an extremely open and tech packed discussion.
Samuele went on to explain that Pirelli’s team blend all SmartGrip compounds in-house in Italy and it does vary tyre to tyre depending on the specific requirements. SmartGRIP makes it easier for the consumer by making the choice more focused on the type of terrain you ride rather than giving a Shore A Hardness figure.
Like we mentioned earlier, getting a Shore A Hardness reading on a pneumatic tyre is hard and pretty inaccurate, varibles such as tyre pressure, casing, knob height, knob size, temperature, how it was cooked, how many rings Saturn has, blah blah you get the idea. To sum up why we couldn’t get a clear reading, “mixing” a tyre compound and “cooking” a tyre is like baking a cake and we all know how Pintrest cake attempts go. This is the exact reason Pirelli mixes the “cake” in Italy and sends the mix to one of many manufacturers globally to bake it. The recipe is perfectly blended for purpose and a uniform product is achieved each and every time.
SmartGrip is nearly 150 years of tyre blending experience and requires trust in what Pirelli does to provide the rider with a compound that offers grip, control and durability.
Samuele noted that Pirelli reigned back the Enduro casing to what is now called HardWall as the original sidewall (HyperWall) was so tough that riders wanted something more supple that would provide more sensitivity to terrain. Throughout the casings, Pirelli have kept the top of the tyre as flexible and supple as possible and really focused on strengthening the sidewall and overall carcass of the tyre without it feeling like a 2 ply downhill tyre, which feels dead to ride. Even the HyperWall protection feels close to a downhill tyre on the sidewall thanks approximately 30mm of inserted protection, but it still feels sensitive on the trail.
We brought up the fact that our tyres are wearing very well, almost too well and that we would opt for a softer than SmartGrip compound even if it meant a big durability penalty. Pirelli after all make Formula 1 tyre compounds in C1 through C5 which are Hard, Medium, Soft, Ultra Soft and Hyper Soft which clearly states that it offers the highest level of grip with a shorter lifespan. Would that be something that Pirelli would offer in the Scorpion mountain bike range?
Samuele smiled, “We are working on a range of downhill tyres with softer race specific compounds, yes”. This was music to our ears, Pirelli aren’t stopping with XC, Trail, Enduro and E-Bike but going all in and chasing the Downhill podium too.
While he explained there have been major global challenges and setbacks, it is likely Pirelli will bring all bike tyre manufacturing home to Italy and work with local EWS and DH teams to further develop their offerings until ready.
Pirelli and the teams of riders involved are working closely with Andreani, the suspension behemoth that specialises in suspension servicing, prototyping, data acquisition and tuning from Formula 1 to Moto GP. So we expectd there is lots of data and Italian racing passion that is going to be exciting to see come to fruition.
We tested the 2.2" Scorpion XC tyres last year - but we also have the Pirelli Scorpion 2.4" Lite tyres, and the XC RC tyres being tested right now.
Pirelli have provided riders with a relatively easy range of tyres to choose from. The Pirelli Scorpion tyres come in 3 casings, pick the terrain you ride most and trust that a team of passionate Italians with 150 years of experience have jammed a heap of tech into it.
While SmartGrip was on the more durable side of the scale, we do applaud them for doing so as we had not one single flat or broken wheel on any casing during the testing period.
With Pirelli looking at doing a Downhill range of tyres using a slightly stiffer sidewall but allowing more compliance and a softer rubber compound, when these tyres come to market these will be the first tyres that you'll see coming out of their Italian factories.The Enduro casing is probably just as thick and stiff as we're finding from a lot of downhill tyres from other manufacturers, so it will be interesting to see if the use of tyre inserts sees a decline with tyres designed to be stiff enough to protect rims but also supple to ride.
Pirelli actually see tyres as suspension, being the first point of contact with the ground and feel that wheels and tyres should be designed as a unit for the best performance. Right now the bike industry makes that hard with so many standards on the go, but perhaps further development of tyre and wheel systems is where we are headed.
RRP: Scorpion Trail $99.99 | Scorpion Enduro $119.99
From: FE Sports