For Kenda's new Pinner Pro tire they wanted to build on a tire already in their line, the Hellkat. The drivers behind the development were a highly predictable tire with low rolling resistance and incredible cornering and braking traction. A familiar story for many aggressive MTB tyres.
Starting with competitor research, Kenda looked at what other brands were doing well and also where they could improve. Tread pattern design followed next in the development process, and they also conducted three different test sessions with Aaron Gwin in three different South California locations with slight adjustments at each stage before they were happy with the Pinner Pro now on offer.
Where the Hellkat is designed to penetrate the soil, the Pinner Pro is designed to be more stable and planted on hard pack, roots and rocks. If there's no need to really dig into the dirt to generate mechanical grip then the Pinner Pro should work well. Not digging in so far also makes it a faster rolling tire.
Pinner Pro DetailsWheel Sizes:
27.5" & 29"Width:
2.4" (61mm), 2.6" (66mm) available in AutumnCasings:
AGC (gravity) or ATC (trail)Compound:
RSR Dual LayerBead:
923g & 1178g for 27.5", 997g & 1297g for 29"Actual weight:
1262g & 1273g (29" x 2.4" AGC)Price:
€60.90 or $84.95 AGC casing, €57.90 or $79.95 ATC casingAvailability:
May 18thMore info: Kenda Tires
Design & Construction
The Pinner Pro has two casing options. The AGC casing is their downhill option and uses layers of woven aramid material, dubbed KVS or Kenda Vector Shield, under the tread area and along the sidewalls. There's further Apex reinforcement along the tire bead to help reduce pinch flats and burping.
The ATC casing is more for aggressive trail riding and uses a higher TPI layers of fabric along the sidewalls and a layer of K-Armour under the tread blocks. The higher TPI, more tightly woven casing material results in less rubber in the casing and so a lighter tire with more suppleness.
The AGC version uses Kenda's RSR dual layer compound idea sees the blocks have a stiffer foundation of stiffer rubber covered in a softer grippier rubber. While the ATC version uses dual compounds again but split differently, with the centre knobs using a harder compound and the side knobs using a softer compound.
There's a Kevlar folding bead and all the Pinner Pro tires are tubeless ready.
Tread pattern is definitely designed for more hard pack and dry conditions. The large block size gives a large surface area and in conjunction with the small spaces between blocks is designed to give a consistent contact patch through all lean angles. The large blocks also give large braking edges and there are alternating sipes in the centre and side knobs to provide more edges for braking and cornering grip while modifying the individual block stiffness to help in transitions between knobs.
Kenda quote 16% less rolling resistance than the Hellkat, with 40% higher puncture protection and 10% less weight to comparable DH tires - we'll see how those puncture claims hold up once we get more time on the tires.
Nothing to do with performance, but something unique to Kenda is their topographic side wall design.
Our 29" AGC test tyres came in at 1262g and 1273g, between 24 - 35g lighter than quoted but within the +/- 65g tolerance that Kenda quote on that particular tire. That's around 110g lighter than a 29" DH casing Schwalbe Magic Marys. A pretty sizeable weight saving at the extremity of your wheel.
Widths are 62mm at the widest point on the blocks at 25psi on a 30mm inner width rim, a touch wider than their quoted 2.4" or 61mm width.
9 Questions with Aaron Gwin About the Pinner Pro Development
Did the drive for a new tire come from yourself or Kenda?
The Pinner actually started before I signed on. It was great timing because they had an initial design concept ready so when I came in, I was able to get right to work.
How fine into the details did you get involved? Did Kenda provide options for you to choose from or were you specifically requesting certain changes in tread pattern, compound and casing?
With this tire they basically presented me with what they had and then allowed me to tweak it from there. It was still a computer rendering at the time so I was able to get in pretty early with my feedback. We worked on everything from tread pattern to knob spacing / sizing, tread compound, and casing etc.
Did you start from a blank sheet with this tire development or was there a foundation tire [in the Kenda lineup. -Ed.] that you took as a base for modifications?
With this tire, we knew we wanted a hard pack / all-around tire so there are definitely certain parameters that you've got to stay within in my opinion. There are only so many different tread patterns that work so for me, it's more about really fine tuning all the little details. The way you space the knobs and position the knobs on the tire has a big impact on the performance. There is also the size, width, weight, and construction of the casing which we really wanted to nail.
Was there a point in development at which you and Kenda both said, stop, that’s the one? Or, as I understand, you’re a fan of testing, so could you have carried on iterating and testing?
I guess you could test endlessly in theory, but there is definitely a point for me where I achieve the feeling and trust that I'm looking for on the types of tracks that we're aiming at. Whenever I get to that point then it's just making sure the tire is durable and able to withstand the abuse that we're going to put it through as much as is reasonably possible.
Are there other tires out there from other brands which you like and perhaps took inspiration from? Did you test these competitors?
I've pretty much tested everything. I like to know what else is working well and I've ridden and raced a lot of these other tires throughout my career. I've found that pretty much all tires have pros and cons so my initial aim is to keep all the things I like and eliminate the things I don't. We've usually got some new ideas that we want to incorporate as well so we just sort of blend all that together to get our initial base design started.
Once we have the renderings and specs dialled in on the computer, we'll make a 3D plastic prototype. This stage is super important for me because looking at something on a computer is way different than actually holding it in your hands.
From that point I could have more feedback on knob size or spacing, etc... that I want to tweak further. We might go through two or three versions of these 3D models before pulling the trigger on starting an actual tire mold. Once the mold is started, you're pretty much committed. There are small things you can change with the mold even after completion but it's definitely not ideal and kind of a last resort. With this tire we actually made multiple molds on purpose with slight changes so that we could test the finalized tires all back to back. That was cool because we were really able to eliminate the variables and prove certain theories that we had on the trail and not just in our heads.
Was there a certain tire pressure range that you’d like to operate in given as an input from you in development?
No not really, I think tire pressure is pretty unique to each person’s skill level and preferences. With that in mind, we try to design tires to work well with a reasonably wide variety of pressures. I've always run my tires pretty firm to avoid smacking my rims. Kenda's have a unique casing construction though and I've actually been able to drop down a few PSI without sacrificing durability which I've never been able to do before. I think our tires also weigh less than pretty much everything else out there and I've found them to be more reliable. It's hard to do both of those things at the same time so I'm really happy with that.
Are tire inserts something you consider during tire development? Does that consideration stretch further to things like wheel and chassis stiffness and suspension setup?
I normally always run the Flat Tire Defender tire inserts front and rear on my DH bike but when we test tires, we'll test with the inserts and without. The inserts can cover up certain weaknesses a tire might have so it's important for me to test the tires both ways. As far as everything else goes, I just try to keep my set up super consistent to eliminate the other variables as much as possible.
Is your racing head always on with tire development? Or do you also give feedback as a more casual every day rider, outside of the races?
I definitely try to think of both, but in my opinion there is not a huge gap there. I sometimes hear people say that the average rider should not be on the same equipment that a top World Cup racer is on and I tend to disagree most of the time. I might run my equipment set up differently but I think the base product can and should work equally well for both types of riders, for the most part. If an average dude was to get on my factory downhill bike and allow us tweak the set up to suit his abilities and riding style, I'd almost guarantee that he's not going to hate it. Ha-ha.
Is there a certain track on the World Cup or US circuit that embodies what the Pinner Pro was made for?
There are certain tracks like Leogang that I guess you could pick out as being ideal, but mostly it's just meant to be a really good all-around dry tire. I would probably race this tire on almost every World Cup track if the conditions were dry. Where I live in SoCal is also perfect so these are the tires that I ride personally every day.
Initial Riding Impressions
Tire installation and setup was easy. They're neither too tight to make it difficult to get onto the rim or too loose that they won't easily inflate with a few gentle pumps on a track pump. They've been installed on two different wheelsets now, one DT Swiss and one Newmen, and exhibited that same ease of installation both times.
Quite by chance, a long running dry spell in Switzerland had just ended when I received the tires, so riding in the absolute bone dry with sketchy levels of dust will have to wait a little. So far, they've been tested in conditions with a little more moisture in the ground and they still grip well, especially on the rocks and slabs that protrude the ground and dry up quicker than the dirt.
One local trail drops around 1200m through varied conditions from softer and loamier at the top to ever increasing amounts of rocks and harder ground the further down you get.
In the softer loamier conditions the tires do penetrate the ground a little less than something with a little more spike, but they still grip well enough and are predictable in these softer conditions. Once the ground gets more compact as you make your way down the trail, and more and more rocks poke their head out of the ground, the tires definitely exhibit really good grip, no sudden slips or pinging off of hard impacts and brake nicely. Leaning them over on flat corners also feels encouraging as you have good predictability even once you've leaned so far that you start to break traction. There is a nice amount of information on tap about what's going on at the contact patch for you to crack on and push hard with them.
The carcass so far feels nicely supple without smacking the rim constantly and I can run them at around 22psi front and 25psi rear set up tubeless with no inserts. Their compact tread pattern does mean they can hold dirt if you're not spinning them up fast enough. But again, for a tire so targeted at hard and dry conditions they've been holding up remarkably well in the softer and damper conditions we have at the moment.
We've got ever increasingly better weather coming our way in Champéry and summer will inevitably bring those dry, hard and dusty conditions that the Pinner Pro is aimed directly at. Once I've worn all the knobs off, I'll report back with a full review of how they perform in these dry conditions, and of course how they fair when they venture out of their dry comfort zone. But so far things are promising and that predictability at all lean angles is something that can definitely be felt.