Tannus Armour Tire Inserts
Size Tested: 29” x 1.95” — 2.5”
Blister’s Measured Weight (one insert, no tube): 324 g
MSRP: $40 per insert
- Maxxis Minion DHF 2.5” (DH casing)
- Maxxis Highroller II 2.3” (Exo casing)
- Maxxis DHR II 2.3” (DD casing)
Reviewer: 5’9” 155 lbs
Locations: Whitefish, MT
Duration of Test: ~2 months
The mountain bike industry is in the midst of something of an experimental phase regarding tires. Bikes have gotten more capable, suspension has gotten better, and people are riding faster, all of which means that the demands on tires are increasing. The result of this is, among other things, a lot of flat tires.
So different companies are offering different solutions. The tire companies are coming out with all kinds of new and different technologies in their casings. Wheel companies are building compliance into their rims and adding things like protective rim strips that are supposed to ward off flats. And assorted companies have released variations on a theme of foam inserts that go inside the tire and cushion against impacts.
The Tannus Armour falls into the latter category … sort of. It’s a foam insert that goes inside the tire, but it functions quite differently than any of the other inserts I’ve seen.
Most foam inserts wrap around the rim in a tubeless tire and essentially cushion the tire when it bottoms out against the rim. The primary idea is to prevent the tire from being sliced when it gets pinched between the rim and the ground, and a secondary effect (which, depending on who you talk to, may be a benefit) is that the tire has a lower air volume, and thus “ramps up” more quickly when compressed.
The Tannus Armour insert is different in two significant ways.
First, the foam sits up against the tire, rather than down against the rim. Second, it uses a traditional tube, instead of being set up tubeless.
Now, a lot of people who’ve been around long enough to have made the transition from tubes to tubeless may be extremely skeptical already. But it’s not that simple — read on.
Design & Construction
The basic premise of the Armour inserts is that there’s a traditional tube in the center, then the Armour foam wrapped around that, all tucked inside the tire of your choice.
There’s a couple of noteworthy aspects of the Armour. The first thing that sets it apart from other foam inserts is that the foam wraps around the entire inside of the tire. There’s a stated 15 mm of foam cushion directly under the tread, and there’s also 2 mm of foam that runs down along the sidewalls to the tire bead.
So the idea is that the thicker foam under the tread protects against impacts and resultant pinch flats, and since that foam is right up against the tire, it can also protect against punctures from pointy things. As an added bonus, the foam along the sidewalls will offer some protection against tears and slices in an area that can be pretty vulnerable. So if you hack sideways into a sharp rock, that rock would have to make it through the sidewall as well as the foam before it gives you a flat.
And, of course, the Armour isn’t set up tubeless — it still uses a traditional tube (albeit a slightly smaller one than you’d normally run for any given tire size). So if you slice a tire or puncture it with a pointy stick, as long as that puncture doesn’t make it through the foam and into the tube, you’re fine. There’s no waiting for sealant to try to plug the hole, and there’s no plugging or patching the tire. In other words, it takes a somewhat significant event to get a flat tire with these.
The big downside of the Armour setup is the weight. My 29” Armour inserts weigh 324 grams each. The tubes that Tannus included are standard 2.1” tubes, which weigh 207 grams each. So that’s roughly 530 grams per wheel, not including the tire.
Now, there’s no tubeless sealant, so there’s some weight saved there — a normal tubeless setup might have ~75 g of sealant. And the 200-ish gram tubes are pretty heavy — I’m sure you could get away with a much lighter tube in there, especially since it’s protected by the Armour insert. A 29” CushCore insert weighs around 270 grams, so the Armour inserts aren’t that much heavier (although there are quite a few tubeless inserts that weigh less than CushCores). But excuses aside, no matter how you look at it, the Armour setup isn’t light.
Setup and Installation
Before we can get into riding impressions, we’ve gotta get these things mounted up. And yeah, it’s not an insignificant task.
Mounting up any tire with an insert in it is a bit more difficult than mounting a tire without — there’s just more stuff inside the tire that you’re fighting against. The Armour inserts are slightly easier in that the main part of the foam isn’t at the rim and around the tire beads, so it’s a little easier to get the beads to drop into the center of the rim.
The problem is that the foam still makes everything quite tight, so I still (definitely) needed tools to get the tire on, and it took some force. The problem comes with the fact that there’s a tube in there. Wrangling a tight tire + a foam insert onto the rim, all while making sure your tools don’t pinch the tube can be a handful. I’ll admit to pinching a tube twice before I successfully got both of my tires / Armour inserts mounted up. Less ham-handed mechanics may fare better.
Overall, I’d rate mounting these as more difficult than any of the foam inserts I’ve played with, including large ones like CushCore.
A note on sizing: I mounted these into a 2.5” Maxxis DHF in the front and a 2.3” Maxxis Highroller II in the rear. Tannus says this insert will fit a 1.95” to 2.5” tire. I’d say shoehorning them into a 1.95” tire would be a biblical struggle, but theoretically possible. I’d also say that they’d work fine in a slightly larger tire — I wouldn’t hesitate to put them in any of the 2.6” tires I’ve tried. I’d probably wouldn’t put them in a 2.8” (or larger), though.
On the Trail
It’s pretty immediately apparent that the Armour rides differently than anything else I’ve ever tried. And the reason for that is clear — on every other tire or insert combination I’ve tried, the tire is supported by air. When I push on the tire’s tread, I’m compressing that air within the tire.
With the Armour, there’s foam immediately under the tire’s tread. So while that foam is supported by the air in the inner tube, when I push on the tire, I’m mostly compressing foam. In large part, it’s the density of that foam that dictates how “squishy” the tire is.
Anyone who’s ever played around with tire pressures and noted the effects on traction (which, I hope, is most of us) will know that this makes the Armour inserts very, very different.
To a large degree, air pressures with the Armour don’t matter nearly as much as they do with a “normal” tire setup. I found that I used the pressure in the inner tube to dial in “bottom-out resistance,” but changes in air pressure didn’t affect traction or rolling resistance all that much. So if I felt like I was bottoming out the tire and hitting my rim, I could add an extra 5 psi in the tube. But adding that pressure had a relatively minor effect on cornering and braking traction, at least compared to making a similar change with a normal tubeless setup (where 5 psi would be a pretty big change).
So it’s really the foam insert and the density of that foam that dictates the ride quality. And I’d describe that ride quality as fairly muted.
It’s a difficult thing to describe, so I’ll come at it from a couple different angles.
First: speed. Air compresses progressively, so a normal tire that’s only filled with air is easy to compress at first, but gets harder the more you try to compress it. The foam in the Armour insert is much more linear, so it feels fairly firm on small bumps at lower speeds. If you’re someone who’s extremely critical / particular about traction (especially at lower speeds), this is worth keeping in mind.
But as speeds pick up and you start running into things harder, the foam starts to feel more “right.” It feels like it’s absorbing impacts and rolling more smoothly through roots and rocks. Generally speaking, I’d say that mellower Trail-bike speeds were a bit too low, but the inserts felt better at higher bike-park speeds. There comes a point at very high speeds where it can feel a bit like the foam is getting overwhelmed on big bumps, but in large part, you can tune that out by increasing air pressure in the tube.
Cornering is somewhat similar in that there’s a certain speed, and a certain amount of force where the tire feels good. Speeds and forces above or below that can feel a bit less dialed — it’s harder to maintain traction compared to a normal tubeless setup with the right amount of pressure. That sweet spot is going to be a little different for everyone, but as with straight-line speeds, I was happiest with the tire’s cornering performance at the higher speeds I’d hit on lift-served, more DH-specific trails. Particularly at lower speeds, the issue is that the foam imparts some stiffness to the tire, so it doesn’t feel like the tire wraps around bumpy obstacles in a corner quite as well — it’s more inclined to skip off of mid-corner chunk rather than ease through it. I wouldn’t say the Armour is terrible in this regard, but it clearly gives up some traction compared to a perfectly dialed tire setup that has just the right tire pressure.
But on the topic of cornering, one nice thing about the Armour is that it provides more sidewall support. I found that I could get away with running fairly low pressures, even with tires that had thinner casings (e.g., Maxxis Exo). With the Armour, I could run an Exo-casing tire with ~23 psi in the tube, whereas with a normal tubeless setup I would (1) almost immediately pinch flat that tire with that setup, and (2) I’d roll the tire off the rim in the first corner. That’s also an area where the Armour distinguishes itself from a normal foam insert — I don’t find inserts like CushCore to do all that much for sidewall support, whereas the Armour definitely keeps even thin tires from getting squirrely in corners, which is fairly noticeable in bermed corners where it’s easy to generate a lot of sideways force.
Another way to describe the muted quality of the Armour is that it, quite literally, sounds muted. Tannus put out a few (really good) videos of some of their fast guys riding the inserts called “The Soundtrack of Tannus Armour” (see below). And they’re not kidding — tires do sound different with these inserts installed. The best way I can describe it: if you’ve ever ridden a properly loamy trail, and the ground sounds kind of hollow, where every impact sounds like it’s off in the distance. That’s how it sounds all the time with the Armour inserts installed. This isn’t really a noteworthy plus or minus in terms of ride quality, but it’s kind of cool.
In my opinion, the main downside on the trail is clearly the weight. It’s noticeable, and it makes the wheels feel slower. For reasons that have been covered extensively by pretty much everyone who has ever written about bikes, rotating weight and unsprung weight matter a lot, and they’re more noticeable than, say, extra grams in your water-bottle cage. The Armour inserts add quite a bit of weight that is both rotating and unsprung, which isn’t ideal.
The silver lining here is that, more so than other inserts I’ve used, you can actually get away with running a lighter-weight tire with the Armour inserts. The Armour inserts offer more protection against sidewall tears, they offer more protection against punctures, and they offer better sidewall support — all of which make them better suited to be paired with a lightweight tire than any of the other foam inserts I’ve seen.
The other downside is that I think they roll slower. I have a really hard time quantifying this in any kind of numerical way, and it could just be that they’re heavier and thus accelerate more slowly. But riding these back to back with a “regular” (insert-less) setup, they feel slower, and I think that may just be due to how the foam allows the tire to roll along the ground. But again, I can’t back this up with numbers, and this is a pretty tough thing to pin down with certainty, so file this under “maybe?”.
I haven’t gotten any flats while running the Armour inserts. The rear tire is clearly where the most abuse happens, and for most of my time with the Armour inserts, I was running a 2.3” Maxxis Highroller II with an Exo casing. Normally, I’d need to run around 30 psi in that tire to keep from flatting, and even then, I’d expect to pinch or slice the tire if I was riding anywhere rocky.
With the Armour insert, I could run somewhere in the low 20’s psi without issue. As I said above, I’d generally run higher pressures to make the setup handle big impacts more gracefully, but regardless of the pressure I was running, I didn’t get any flats when using the Armour inserts.
Now, I was mostly riding these through the spring, and the higher, rockier trails that are a better test of flat protection were still under snow. So I’ll report back after further testing, but I’m fairly comfortable saying that, if flat protection is your main goal, the Armour inserts are arguably the most compelling option on the market, primarily because they protect against two kinds of flats (punctures and sidewall tears) that aren’t really addressed by most other inserts.
As I just mentioned, I haven’t had enough time in legitimately rocky terrain with the Armour inserts to really test their long-term durability. But so far, they’re holding up well.
Plenty of foam inserts will noticeably deteriorate over time — when the foam gets pinched on impacts, it gets sliced up. Eventually, the foam just kind of falls apart. I expect that the same thing will happen with the Armour inserts eventually, and there’s already some minor evidence of a few hard impacts in the foam. But that evidence isn’t a significant tear — it’s more of a minor dimple. So while I’m sure the foam will eventually deteriorate and need to be replaced, I’m not seeing any evidence that that’s happening exceedingly quickly.
The fact that the Tannus Armour insert setup weighs somewhere in the neighborhood of 500 grams (with the tube) will take these out of contention for a lot of people. The fact that these things even use a tube will probably mean a lot of people are going to rule them out. And, of course, plenty of people happily get along just fine without any kind of extra flat protection. The Tannus Armour setup is not for those people.
But then there are the people who have resorted to running 40 psi in a DH-casing tire. There are the people who never wear out the tread on their tires because they always gash the sidewall before the tread’s done. There are the people who aren’t that concerned about weight because they’re mostly riding lift-served or shuttle laps, and they just want a bomber setup. These are the people who should be looking at the Armour inserts.
There’s also the fact that the Armour inserts are fairly cheap compared to the competition. $80 for a pair of Armour inserts starts to look pretty attractive when you consider Cushcore inserts will run you $149. You can, however, get for a bit less money a less protective (although much lighter) option, like Huck Norris.
The Armour inserts offer better sidewall and tear protection than any other insert I’ve seen. And while the traction provided by the foam isn’t quite as good as a normal tubeless setup at normal tire pressures, if you’re the kind of person who needs to resort to super high pressures to keep from flatting, the Armour insert might be your ticket. It’ll provide better traction than 40 psi in a DH tire while also offering better flat protection.
So no, the Armour insert isn’t for everyone. But for the people who are the hardest on their equipment and just want the air to stay in their damn tire, the Armour insert might be their best bet.