In the growing market for tire insert systems, Tannus Armor stands out. In an age where tubeless tires have become accepted as the norm, the new foam insert wants you to bring back the classic tube.
Tannus Armour ditches tire sealant in favour of a foam insert that wraps around between a traditional tube and the rim/tire. The new system uses Tannus’ own Aither 1.1 foam technology, a proprietary material derived from Tannus’s airless road tires. Airless might not have caught on just yet, but the mountain bike-focused Armor is an interesting idea. Like many of mountain biking’s innovations, its a low-tech but novel approach to a long standing problem.
By wrapping almost all the way around the tube, Tannus protects against the main weakness of tube systems: pinch flats. The foam stays between the rim and tire on harsh impacts, and provides more sidewall support to help reduce the number of such impacts. That extra sidewall support, Tannus claims, will also let you run lower pressures for better traction on trail, but without your tire folding under hard cornering.
If you still balk at ditching sealant for a return to tubes, Tannus offers the potential to protect against the main weakness of tubeless: slashed sidewalls. While tire plugs are improving riders ability to stave off punctures, a long cut across the sidewall will still end most tires, even with a flat protection system installed. Tannus adds 2 mm of extra sidewall protection, in addition to the 15 mm of puncture protection on the top of the tire.
In addition to flat protection, which will likely be why riders might hesitate to return to tubes, Tannus claims the system will let you ride faster. Improved traction through the ability to run lower pressure than tubeless, added shock-absorption through the foam insert, and the ability to ride out a flat at up to 15 km/hr are Tannus’ claimed advantages to adding its foam insert to your tires.
Tannus Armour runs at $40 USD per insert. Compared to other insert systems, or the price of replacing a rim, it’s a less expensive option.
Installing Tannus Armour
Compared to tubeless systems, which can require an air compressor or special pump to get properly seated, Tannus’ tube-and-insert approach can be installed at home with just a pump and set of tire levers. The process isn’t much different than installing a normal tube, just with the extra layer of Aether foam.
Following Tannus’ simple instructions, I had the system installed in about 10 minutes per tire. The tube sits inside the foam, which provides some support as you install it into the tire, then onto the rim. On the rim, the foam wraps most of the way around the rim. This gives near 360-degree protection for the otherwise-vulnerable tube, keeping it away from the rim to prevent pinch flats, and away removed from anything poking through the tire while riding.
The foam does take up some limited real estate inside the tire, making install slower than just using a tube. Since you cant get the tire bead as deep into the channel in the centre of the tire, it makes getting the last bit of the tire mounted on the rim more difficult. Getting the last couple inches of tire onto the rim accounted for a solid third of the install time, and required a sturdy set of tire levers. Anyone with tougher hands could shave minutes off my time, per tire.
On the plus side, there’s no sealant to worry about sloshing around, or seeping out as you try get the tire to seat on the rim. Once the Tannus and tire were on the rim, getting the rubber to fully seat on the rim was simple and, with the foam holding everything in place, can by done with a hand pump if you want.
Riding Tannus Armor in #Gnarnaimo
After setting up the Tannus Armour on my Chromag Rootdown and taking a couple short test rides to make sure everything was working alright, I headed straight to the deep end. A big ride on Nanaimo, B.C.’s Mount Benson trail network would quickly sort out whether the tube-and-insert system would hold up, or go flat under pressure. Benson’s combination of steep, rocky technical trails and high speed root-strewn fun has left rims wounded in the past. Adding to the challenge, in my rush to get out the door that morning, I’d brought the wrong pedals, forcing me pull out an emergency set of flat pedals, which live in my vehicle for exactly this occasion.
Whatever grace I have on a bike went out the window. While I’ve gone back and forth between flats and clips with some frequency, the first ride is always a bit rough around the edges. The warm up trip down Üterbraten, the top section of Nanaimo’s Simpsons-themed trio leading into Max Power and Sexy Flanders, is a more natural trail mixing off-cambres, tight corners, deep holes and constant roots. Carrying any speed means staying light and skimming across long sections of roots. Instead, it felt like I slammed the Chromag’s back end into every hole and pinged off every-other root (there are alot of roots). I was sure I’d dented my rim and impressed I hadn’t flatted the tube at the core of the wheel system. Tannus Armor survived this first graceless test unscathed.
The next section would be more challenging. From the 1,050 m summit of Mount Benson, Chainsaw Ridge, Meatdraw and Rollercoaster string together 4.6 km of singletrack, losing 750 m of vertical elevation along the way. Starting with the exposed rocky chutes and slabs of Chainsaw Ridge that have helped the town earn the nickname #Gnarnaimo, the sequence of trails slowly builds from tech to speed ending with the fast paced berms and jumps of Rollercoaster.
While I was feeling more comfortable and finding my flow, Tannus Armor was still forced to survive being slammed into rocks, one unintentional drop to flat, and enough cases to keep a small law firm busy for months.
A couple rides isn’t enough to judge Tannus’ claims that the insert will help you ride faster, give you better traction and provide more vibration dampening. But it was a solid sign that the tube-and-insert system will survive being ungracefully slammed through roots and rocks at reasonably low tire pressures. The liner is flexible but, installed in the tire, provides a noticeable increase in sidewall support. It will be interesting to see how low tire pressure can go before the Tannus system starts feeling squirmy. Starting a bit higher, I kept dropping pressure until I was 4-5 p.s.i. below where I’d normally be by the end of the ride.
If you want more proof that Tannus Armor is just fine getting airborne and sideways, here’s pro rider Luca Commetti showing that the system can handle a couple 40 foot gaps and warp speed: