Words by Trevor Mejia / Photos by Liam Woods
Tire inserts have become commonplace in how riders set up their bikes for particularly aggressive trails, racing applications and e-bike riding. A new tire insert we have been digging is the Vittoria Air-Liner Light Insert. The idea is that you can add protection to your wheelset while at the same time giving the ability to run lower pressures for more grip and not have the tire roll or burp air. If your tire does completely fail on you, you still may be able to ride down the rest of the trail without causing further damage to your rim. This has been a game changer for getting the most grip out of your tires and also decreasing the event of catastrophic failure of carbon rims. The downside to these inserts is that there is a severe weight penalty to rolling weight, which is a big deal to those who want to be able to pedal fast and efficiently. Some brands like Cush Core have created an “xc” version of their insert but with the weight at 150g per insert, these are still too heavy for those looking to keep rolling speed and cut weight. We have found that they work better in a front tire with a normal sized insert out back or on a bigger travel bike for some additional protection and confidence.
Vittoria has managed to create a lightweight insert with the Air-Liner Light at an impressive 55 grams aimed at xc racers and “down-country” trail riders. With this minimal weight penalty, riders can have more confidence in their wheelset and tires while being able to find the balance between a lightweight, thin casing tire and low tire pressure.
The Air-Liner Light is a lightweight foam insert that sits in the inner channel of the rim and is formed as a specific v-shape. This allows for protection for the tire bead, snake-bite punctures and hits from the side of the tire. The inner area of the V creates a high volume air-channel in the middle of the tread for better ride feel and compliance. Vittoria claims that the insert creates progressive compression for more stability under lower pressures and decreases the ability to burp air out of the tire. They also claim that in the event of a puncture, the insert will expand so that you can get to the bottom of the trail or finish your race run. While riding under normal air pressure, the foam insert actually shrinks to smaller than when it is uninstalled. The insert also does not absorb sealant which is important considering that some inserts out there are porous and will eat your sealant. Vittoria has worked with sponsored world cup xc racers and mechanics to this insert to meet the demands of what xc and trail bikes are currently capable of.
Something that deters many consumers from getting inserts is the installation. Tire inserts are historically a huge pain to install and take a lot of technique and patience to get right. Sometimes, if the installation is forced without good technique, the tire bead will warp and you will not have a true tire. Most of the time it is easier and saves frustration to just pay a mechanic to install it the right way. With Vittoria's new Air-Liner Light, this is not the case. It is as simple as installing a normal tubeless tire. Get one side of the tire bead on the rim, install the liner into the rim channel, get half of the other side of the tire bead onto the rim, pour in your sealant and finish installing. It is really one extra step and not much of a hassle compared to every other tire insert that we have installed. It is important to note that with this liner you will have to run a multi release valve so that the air can flow from the sides of the valve. The liner comes with one but we installed a Trail One multi-release valve stem as a replacement.
Out of the box, I could not believe how light the liner was. 50 grams is really not a lot of weight and from that aspect alone I can't see a reason to not run this liner in any cross country or trail bike. Along with the liner, we were sent a set of Vittoria Agarro and Mazza trail tires to test out. The liner was installed in the rear tire as this is where I see it as most important for protection but if we had a second one I would have put it in the front to be able to drop tire pressures with the light casing tire. I typically will run 28 and 24 psi regardless of bike and tire setup but with an insert I have found to be able to run 26 and 22 psi to find more grip without feeling the dreaded rolling sensation. Just 2 psi can make a big difference in how your bike rides and feels. It is hard to tell while riding that the insert is even in the tire and it definitely helps with traction and damping as a whole having the lower pressures. I have to say that during my second run on a rocky trail I sliced open the Agarro and lost all the air instantly. I dreaded a broken wheel but was surprised to see that it was fully intact. I am confident that if it were not for the airliner that the wheel would have failed as well. I have broken other carbon wheels in the same manner as before but the liner did its job as it should. The slash was large and not able to be fixed with a tire plug, so I had to take the liner out and replace it with a tube. This is a bit of a pain and can be messy but it comes with the territory of running a liner in the first place. A couple of us at the shop are doing the Downieville Classic XC/All Mountain Race and we will be equipped with the Vittoria Air-Liner Lights in all of our bikes as this is the perfect tool for the job.
There is something to be said about the material of this insert vs other inserts. While this is in a weight class of its own (55g), the material is a very lightweight and non-dense foam. When you have harsh rock strikes that could potentially damage your rim and tire, this will help that, but at the expense of damaging the liner as well. The image below is damage from after the Downieville Classic Race where a rock strike caused a snake bit puncture on the tire and it was ridden on a flat for a few miles to the finish line. There was significant damage to the insert and it will need to be replaced but it did prevent the rim from being damaged further! So it did do its job and the snake bite flat was due to bad line choice at the end of day 2 at the Downieville classic, without this insert im positive the rim would have been damaged. Other inserts like Tannus and Cush Core use a dense foam that is not easily damaged and are true "run flats". We see this Vittoria inserts being used primarily as xc race applications where weight savings is of the biggest concern.
Vittoria has knocked it out of the park with the Air Liner Light tubeless mountain bike tire insert. They have found the perfect balance for a rider who wants rim protection and peace of mind for their cross country/trail rides while also providing a superior ride feel and added traction, without the typical weight penalty of a tubeless insert. The only downside to having an insert, and this goes for all inserts, is that if you do flat and want to install a tube, you will have to find a way to carry the insert out either strapped to your bike or shoulders in a bandolier fashion. This is not the end of the world however and we think that the advantages of having this insert installed far outweighs the negative. Here at Worldwide Cyclery, we are big fans of this new insert and will be running it on many of our bikes in the future.