Vittoria Air-Liner Tubeless Insert - MTB, X-Large (2.8-4.0") Foam-Based Run-Flat Protective Insert with Rim & Tire Shielding, Enhanced Grip, Puncture Prevention, and Bead Lock Technology

Each kit only installs on ONE tire. If you're setting up your wheels for the first time you'll need two kits. Biggest thing to pay attention to with these. It takes longer to install a tubeless tire than to install the Vittoria Air liner and doesn't require any special tools. Except maybe for a nail to make the hole that allows the zip tie to connect the two ends. Amazingly simple install- size/cut/cable tie together/mount on the rim (with a one tire bead already installed) and that's it. IF it takes more than 5 minutes it's because you spent that time drinking a beer.

My wheels are 29 x 3.0 and I ride them at 8 and 13psi since the install without a problem. I have better traction climbing now than before and especially in the corners (since the tire can't roll around as much as much). I also haven't heard my rims sing out once on the square edged rocks that infest my riding areas. There's no point in carrying a tube since these can be ridden out with a flat tire (claimed 100 miles) if a Stans Dart can't cure the problem. Impressive for the money and worth it.;

I'll keep this as short as I can and still give the big picture: I have these on three bikes and am about to buy one more for my final tire. They absolutely make a difference and do exactly what they're supposed to do. I'm a pretty heavy rider at 220lbs or so and these let me run a solid 5psi less than I normally would. The biggest point now is that I'm running a big 2.8" tire and they're notorious for squirming at the bike park. The air-liner stops that.

Now as far as installation: yes the first time you install these you'll learn all kinds of new and offensive four letter words. Still nowhere near the faff with cushcore. Not even close. And once you get the hang of how to get the tire sat in the right place on the rim it's literally no different than installing the tire without an insert. That was the real turning point for me.

One of the coolest things they do (and it's very subtle) is dampen the feel of the tire. It's **almost** like getting your suspension tuned better. It's not drastic but it's quite obvious.;

Must have for plus hardtails like the Trek Stache on the rear. Gets rid of the bounce on plus tires smoother ride less squirm more grip awesome rim protection. Only downside is the weight and it's not that heavy.

Wanted to use this to keep my 20x4 tubeless tires from losing their bead on cold mornings on my commute it may work to keep the rim from getting damaged... but the width of the foam is maybe 3" wide not nearly wide enough to fill the tire more than 1/2 way. Also the diameter is not wide enough even if I cut it in half lengthwise to "rim lock" the beads from the inside. Returned because it advertised for 4" wide tires but clearly is not designed for that and I'm not going to rig something together and use $80 of foam that doesn't work and I would not be able to return if it failed. I'm sure it works amazing for narrower rims.

Ended up using some rubber / silicone weatherstripping on the inside of each rim trimmed down with a 1/4 or so gap between the rubber edge and the rim edge for the tire to fit snug. Push it in with tire spoons pour some tire sealant in inflate hear the "pop" of the tire bead seating. That tire bead is locked in now! 3 months of commuting with my 90 lb loaded bike and no bead loss at low pressure/freezing weather.;

I have the medium size 2.5 model to fit in my Stans Baron (35mm internal width) with Rocket Rons 27.5x2.8 size tires tubeless on stans sealant. The insert has about 4-6mm gap between the tire. Its a perfect fit and insert doesn’t flap around inside once you strap it to correct size. Each insert weighs in at 213 grams cut to fit 27.5 (or 650b) size rims. I ran my tires at 0 and 5-8 psi to see if it can be used as run-flat tires and yes you can! The tire stayed seated on the bead and I was able to climb up the hill in slow motion. Going down the hill was slow motion too since it was squirmy around the turns but you can use it as run-flat tires without hitting the rims. My normal psi is 12 to 14 and I use this on my Guerrilla Gravity Pedalhed 27.5+. Those squre edge rocks and roots doesn’t scare me anymore. I don’t ever hear/feel the rims bottoming out whenever I hit those obstacles. The weight is noticeable especially if I go lower psi where I’m pretty riding on the inserts. It is draggy but if I inflate to 13+ psi the tire doesn’t feel draggy at all. I put my psi at 12 and by the end of the ride my psi is up at 14 especially on warm days. Without insert the psi only goes up to max 0.6psi more so it would only be at 12.6 psi as opposed to 14 psi with insert. I chose the Rocket Rons in the rear because it only weighs 777 grams + 213 grams for the insert and I get a lot of braking and cornering traction since I have low psi but its doesn’t feel draggy like my Purgatory 2.6 (960 grams) without insert at 16 psi. The front tire I have Butcher Gripton Grid 2.8. Psi are low because I’m lightweight at 145 lbs and I ride light on my bikes.

Update: 10/29/19 - I tried this insert in my Full Suspension bike 2019 Stumpjumper Expert 27.5 and noticed that the rear end bounces a lot. I didn’t notice this on my hardtail (Pedalhead) because it’s expected to be bouncy (Hardtail). The bounce is coming from the very densed foam and I’m pretty running on the foam itself and not the air in the tire at 12 psi (rear). I compared the riding characteristics with this vs the Huck Norris and Huck’s are better in terms of traction because you can run 12 psi without it feeling bouncy. It just feels like running 12 psi without insert until you bottom out the tire and you feel that foam protecting your rim/tire.

Air Liner is better protecting your rims and tires from pinch flats but suppleness (riding performance) I would go with thinner liner such as CushCore or Huck Norris.;