All Mountain? I Don’t Think So! The New Michelin Force AM Tire, Reviewed

Photo: Wil Matthews

Michelin is an absolutely massive tire company. On a global scale, Michelin nets €21 billion per year in revenue, and last year this French behemoth spent €700 million on R&D alone. While Michelin has had a line of mountain bike tires in the past, in 2017 they’re signaling their re-entry into the mountain bike market by bringing four completely new lines of tires–totaling 16 different tires–to market.

Launching 16 tires in one year (with more on the way next year) is a massive undertaking, but when you have the weight of a company like Michelin behind you, the prospect starts to look a bit more achievable. While all of these new mountain bike tires were designed by one engineer, Vincent Ledieu, he had the research and tire compound knowledge of a vast array of Michelin scientists at his behest. Many Americans love to talk about supporting small businesses and local companies, but often times there are very real benefits to working within a major corporation.

The four tire lines that Michelin is launching this year (available at retailers soon) are the Jet XCR, the Force XC, the Force AM, and the Wild AM, listed in ascending order of gnarliness. The Force bridges the XC and AM spectrums, with the XC version offering much lower profile lugs than the AM. Check out this graphic to visualize how Michelin’s new offerings are arranged across the spectrum of mountain biking (Michelin claims their tires cover 80% of riders):

Screen Shot 2017-03-10 at 9-2

While I had the opportunity to test the Jet XCR, the Force AM, and the Wild AM at Michelin’s launch in Santa Barbara, CA, I’ve spent the most time on the Force AM so far, so I’ll focus in on this tire.

Force AM Specs

Photo: Will Matthews
Photo: Wil Matthews

The Force AM comes with two specific Michelin tire technologies: Trail Shield Technology and Gum-X3D Technology. In layman’s terms, the Gum-X3D technology is a combination of three different rubber compounds to offer an excellent combination of traction and fast rolling speed. The Trail Shield Technology is simply anti-flat robustness built into the tire.

This tire features a fast center tread pattern with somewhat aggressive side knobs for cornering prowess.

I tested the Force AM in the 29×2.35″ model, which weighs in at a claimed 770g.

While the Force AM claims the term “all mountain,” apparently that means something different in France, where Michelin is based, than what I think of when I hear “all mountain.” I questioned the Michelin folks about how they differentiate “all mountain” from “enduro,” and they said that in their opinion, enduro is basically just going downhill. Michelin does have some enduro tires in the works, which we’ll hopefully see in 2018.

In my opinion, based on my first glance (and backed up by my testing, below), I’d label the Force AM as a fast rolling, light duty trail bike tire. An all-mountain tire or even a competent trail tire, it is not. Here’s how the test went down.

Out on the Trail

Starting off on the Jet XCR. Rider: Greg Heil. Photo: Will Matthews
Starting off on the Jet XCR. Rider: Greg Heil. Photo: Wil Matthews

The good folks at Michelin wanted us to test all of their various tires on back-to-back shuttle runs. While the forest service officials had other plans and closed our shuttle road, we improvised… which meant lots of pedaling! Our first test was on a mellow XC trail on the Jet XCR. XCR stands for cross country race, which is undoubtedly not my forte. This tire is ultra lightweight, has extremely minimal knobs, and I found the light casing to be very squirmy while landing even small jumps.

Next up was the Force AM. For this test, we began with a set of the Force AMs mounted both front and rear. Our test course featured a steep 6-mile loop with 1,500 feet of climbing and 1,500 feet of fast, technical descending. On the first ride, despite the mechanics setting the tire pressures at a very exact recommended pressure, I took some air out of the tires, down to roughly my standard preferred pressure.

On the initial climb, the Force AM found purchase in the sand, gravel, and bouldery slickrock sections, rolling fast and keeping the train moving right along.

Those fast rolling, low profile characteristics proved to be extremely unsettling while pinning down the mountain. The top section of the trail was flowy, with a gravelly loose over hard surface, but the tires didn’t hook up nearly as well as I was expecting, sending me into a two-wheeled slide toward the edge of the mountainside in just the third turn. Thankfully I was able to self correct, preventing myself from going over the precipice. In the presentation earlier that day Michelin claimed that they tried to engineer tires that drifted as reliably as possible, and I think that reliability in the transitional zones saved my skin!

Holding on for dear life through a ledgy section. Rider: Greg Heil. Photo: Will Matthews
Holding on for dear life through a ledgy section. Rider: Greg Heil. Photo: Wil Matthews

After realizing that I wasn’t going to get the traction I wanted out of these tires I backed off the gas significantly, yet I still found that the front tire completely failed to hook up in some looser sections, creating an out-of-control careening-down-the-gulley effect. While this could be expected based on the Force AM’s leaning towards “Hard/Dry” conditions in the chart above, finding a trail that’s both hard and dry all the time is a rare feat.

As the trail descended, the rock gardens grew rapidly in size, and we funneled into some gnarly chutes and long stretches of chunder. While already backed off the gas, as I dropped into the sharp-edged rocks I smacked my rims several times. Time to back off the gas yet again! While I thought the tire pressure set by the techs was way too high, apparently that pressure was chosen to guard against flats and blowing up wheels. Thankfully, I found the Trail Shield technology to do its job, and I lost no air pressure and didn’t pinch flat the tires.

Another tester on our ride wasn’t so fortunate. His Force AM rear tire sprung a leak on the climb, so he tubed the tire at the top. Within the first three turns of the descent, where the trail was almost butter-smooth and uber-fast (where I almost drifted off the side of the mountain), he somehow managed to pinch flat his tube–in a zone with absolutely no obstacles. Another tube in the tire, we pumped it up to about 35 PSI to hopefully prevent this from happening again on the remainder of the descent. While the Trail Shield held for me personally, I was also trying to ride as gingerly as possible after seeing my friend’s flats up high.

Gavin Godfrey getting feisty on an XC trail. This guy can style any little lip! Photo: Will Matthews
Gavin Godfrey getting feisty on an XC trail. This guy can style any little lip! Photo: Wil Matthews

For lap #2 on the Romero Canyon trail, the techs set us up with the Wild AM tire up front and kept the same Force AM tire in the rear. After my drifty out-of-control ride down earlier, I quietly asked a mechanic if they could set me up with the Wild AM on both front and rear. Word got back to the higher ups, and they asked politely but firmly if I could test it the way they wanted me to test the tires, with the Wild/Force combination. According to Michelin, this is a “playful” tire combination. I acquiesced, but made sure that the techs reset the tire pressures exactly where the Michelin folks wanted them to be. Those pressures turned out to be way higher than I generally prefer for optimal traction, but I did not feel like changing a flat.

The Michelin folks were adamant about mixing and matching the Wild AM with the Force AM. In fact, in their press release they state: “Riders will be able to combine front and rear tires of different ranges in order to fully customize their ride experience, a first for the market.” I’m not quite sure what market they’ve been watching, but mixing and matching different front and rear tires is extremely common amongst most mountain bikers that I know and ride with. In fact, I almost never ride with the same front and rear mountain bike tire. While I appreciate their approach, calling this a “market first” is a serious stretch. Even calling this a first for Michelin is a stretch, because there was nothing that prevented riders from doing the same thing with Michelin’s previous offerings.

Cam Zink rode with us in California, and he had a Wild/Force tire combination mounted on his own YT Jeffsy. Michelin developed these tires in close partnership with riders like Cam. During testing, the engineers emphasized trying to think like a general consumer as well as a pro. But even at his mellowest, Cam Zink is 10x the rider I'll ever be. Photo: Will Matthews.
Cam Zink rode with us in California, and he used a Wild/Force tire combination mounted on his own YT Jeffsy. Michelin developed these tires in close partnership with riders like Cam. During testing, the engineers emphasized to the pros that they should try to think and ride like a general consumer during some tests, as well as a pro in other tests. But even at his mellowest, Cam Zink is 10x the rider I’ll ever be. Photo: Wil Matthews.

The climb flew by yet again despite a burlier front tire, and I dropped into descent #2 much more aggressively and confidently than before.

While calling the Wild a “burly” tire isn’t accurate, when compared to the Force AM the handling in these gravelly, technical conditions was night-and-day better. However, that improved handling was only happening up front–my rear was even more out of control due to the higher tire pressures.

If calling a tire combination “playful” means “it slides all over the place in even slightly loose conditions,” then “playful” is the perfect descriptor. However, as before, I found the Force to drift very predictably, but with the high pressures, it was drifting all the time in the rolling rocks. As I descended, I quickly reached the point where instead of just trying to corner and expecting my tires to hook up and actually work, I’d grab a handful of brake in order to initiate the slide under my own terms instead of waiting for the tire to break free later.

In no way is this the fastest way to corner, and it generally isn’t good for the trail. But when it’s a decision between sliding off the mountain or finding that drifting sweet spot and riding it out, I’ll choose the integrity of my body over the integrity of the tire tread every time.

Russell getting airborne. Photo: Will Matthews
Russell getting airborne. Photo: Wil Matthews

As we reached the rock gardens, the increased tire pressures and the confidence of the Wild AM up front allowed me to take my preferred point-and-shoot approach, with the YT Jeffsy feeling like way more than 140mm of bike! In fact, getting to ride the Jeffsy for the first time was one of the highlights of the day for me–more on the Jeffsy in a separate review.

Upgrading the tire combination to the Wild in the front and the Force in the rear made for a much more confident and enjoyable ride. However, would I have had more fun riding this trail with the Wild both front and rear? You bet. How about a Maxxis Minion up front and a High Roller II in the rear (my current tire setup)? Even better.

Gavin Godfrey can backflip seemingly anytime, anywhere. But if you were the first person in the world to throw a triple backflip on a mountain bike, that's kind of expected. Photo: Will Matthews.
Gavin Godfrey can backflip seemingly anytime, anywhere. But if you’re the first person in the world to throw a triple backflip on a mountain bike, that’s kind of expected. Photo: Wil Matthews.


However you choose to label the Force AM, “confident” and “reliable” are not terms that I would associate with this tire. Personally, I wouldn’t use this tire in any of the terrain that I ride here in Colorado. Even on flowier trails in hardpack conditions with some decomposed granite on top, based on my experience in California I’d expect this tire to break traction very easily in those classic Colorado conditions. I considered that this might be a good choice for the rear of a hardtail 29er, but thanks to the singlespeed drivetrain on my own personal 29er I have to put down a significant amount of power when climbing out of necessity, and I need a tire that won’t spin while doing that. The Force AM is not that tire.

would feel confident using the Force while riding the hardpacked clay trails of Georgia (when dry), especially the trails that are rootier and not as rocky. The fast rolling profile of the Force AM would would pair well with those conditions. That said, I used to run a Kenda Small Block 8 tire in those conditions. So maybe calling this a good Georgia tire really isn’t saying much.

Bottom Line

Despite the differences in terminology from one country to another, the Force AM is in no way “all mountain.” As you can see, I think that the Force AM failed to perform even on the trail that Michelin chose as the testing grounds for this tire.

If you do light duty trail riding on generally hard-packed and dry trails, with few obstacles, the Force AM could be a decent selection for you. But for anything more aggressive than light-duty trails, or when the soil gets even a little bit soft and loose, I can’t in good conscience recommend this tire.

I am, however, excited to test both the Wild AM front and rear. Due to the way the test was organized in Santa Barbara I wasn’t able to test this combination yet, but I do have several sets of tires en route to Colorado for long term testing. Stay tuned!

The Force AM will be available May 2017.

Thanks to Michelin for making this test experience possible.