Tannus Fusion is the world’s first modular tubeless tire insert system. Made of two interlocking components, the system allows riders to select the exact amount of desired tire protection. Each portion of the Fusion insert can also be used individually, for applications ranging from road to trail riding. Spencer recently got his hands on a set of the new Fusion inserts, which are launching today, and set them up on a couple of his bikes. Read on for his review…

When Josh and I were at the Sedona MTB Festival last month, we noticed something interesting in the Tannus booth. The Fusion system combines two of Tannus’ existing tire inserts – Pro and Lite – to provide a total of 30mm of rim protection. Tannus has been expanding its product line in recent years, with Tire Armor for tubed setups like John reviewed, and tubless options that include the innovative new Fusion insert system.

Fusion consists of two interlocking Aither foam inserts, the Pro and Lite, which can also be purchased separately. The Lite can be used as a standalone road or gravel insert and the Pro can be used for general-purpose MTB riding. Combined, they create a Fusion insert with the highest level of protection Tannus offers.

There are many reasons to run tubeless inserts, though most people will use them to protect their rims from impacts. Additionally, tire inserts can help support tire sidewalls, minimize pinch impacts at the bead, and allow for a more tuneable air pressure. The Fusion system goes a step further, providing a customizable degree of protection through using one or both of the included inserts.

Quick Hits

• Lite
  • 10mm thick
  • designed for 700 x 33-45c or 27.5 x 1.9-2.1″
  • 50 grams
  • $29.95 per insert
• Pro
  • 20mm thick
  • Designed for 29/27.5 x 2.1-2.6″
  • 140 grams
  • $49.95 per insert
• Fusion (Lite and Pro combined)
  • 30mm thick
  • Designed for 29/27.5 x 2.1-2.6″
  • 190 grams
  • $69.95 per insert

Installation

In my experience, the bane of every tire insert is the installation process. Especially with tough casing tires. The past few carbon wheels I reviewed were so difficult to install an insert on that I simply gave up. I have cursed, yelled, and thrown things many times trying to get tire inserts installed. But, I’m trying again, so follow along below, and let’s see how this goes…

I jumped into the deep end and installed a Pro insert on my WTB CZR rims first. It took a bit to make sure all the “teeth” of the interlocking inserts fit together before wrapping the insert around the rim. The Tannus Pro did seem to be initially more compliant than other inserts I have installed in the past. Installation still required wrestling to get the bead started and finally roll the tire all the way on.

Pardon the plug for a competing company, but I was gifted a Cush Core Bead Bro at Sedona MTB Fest. I had been using wood clamps to try and hold the bead on for that final push, and the Bead Bro proved to be a lifesaver. I highly recommend getting one for all tire installation. In the end, my Tannus Pro install went smoothly with no swearing or yelling at all.

The combined Fusion insert was the most difficult to install, understandably, with the two halves (Pro and Lite) being much less stressful to install individually.

Insert Permutations

I haven’t had any issues with flats or rim dents on my front rims, so I’m not sold on installing a front tire insert. After installing the Fusion combo in my rear wheel I had an extra Fusion combo left over. So, I decided to split the two modular parts for use with two additional bikes (and for testing purposes, of course).

The Lite insert is installed on my Specialized Sequoia with 700x42c tires. While this bike is mostly a road bike for me, it occasionally gets underbiked so this small amount of protection will be appreciated for the errant baby head rock or curb hop.

The Pro insert will be going on my Crust Scapebot touring rig. Tire inserts can truly shine on a hardtail or rigid bike, so onto my rigid 29er touring rig it goes. Having that extra bit of protection will be welcome for the rough two-track down in Southern AZ while running more comfortable tire pressures.

First Ride

Right after installation, I did what any good reviewer might do – remove all the air from my tire and run it into some curbs. The Pro insert, which offers the most individual protection of the system, felt fine being rammed into a curb.

The Fusion model claims to be “run flat capable.” I pedaled with no air in the tire and, while I wasn’t riding on the rim, I wouldn’t want to pedal very far on just the insert. It is better than nothing, but the sidewall creasing of extending riding like this would probably significantly wear out a tire. But again, it could get help get you out of an unpleasant situation.

Pros

• Modular inserts offer options and customization
• Tantrum-free installation (for me)
• Lite and Pro models are priced reasonably

Cons

• Fusion insert is expensive, but most people don’t need that level of protection
• Still relatively difficult to install

Initial Impressions

I like the modular aspect of the Fusion system. You could buy a set of the inserts and use them for one to four separate bikes. Combine the Lite and Pro for a fusion system when you need it or split them apart for lighter duty on other bikes. While the full-on Fusion system seems great for its super high level of protection, I’m most excited about optional ways to utilize the two halves. The Lite piques my interest for many applications, from gravel riding to touring.

The installation was smoother than my past experiences with installing tire inserts, but I had the proper tools finally. With some proper tools, most people should be able to install these inserts on their own, especially the Lite and Pro models with the fusion needing a bit more skill and gumption.

I’m looking forward to smashing these inserts into the plethora of rocks Arizona riding will have in store for me!

Check out all the info and options over at Tannus.