I’ve been riding Bontrager CX0s for a few years now, and literally have thousands and thousands of miles on them. I burned through two sets of 700x38c tires on the Vaya (both sets going completely down to the threads, after rotating front to rear), and have burned through 2 front tires and 3 rear tires on my Moots (I’m now on my 2nd front tire and 3rd rear tire on it), and closing in on my 4th rear tire. On the Moots, I run a 38c up front and a 34c in back. All told, I’ve gotten into 5-digit total mileage on these tires, which is saying something.
In all that time, I’ve only really written about them once, now nearly 2 years ago…so with the amount of time that I spend on them, I thought it was time for an update and a proper review.
This front tire has about 1,500 miles of gravel on it, and still looks relatively new.
The rear tire has about 2,000 miles on it, and is starting to get that telltale slick stripe.
I’ve run them set up tubeless for nearly all of my mileage (the Vaya does have a tubed set on it right now, as it doesn’t see riding as often), and all of it has either been on Stan’s Crest rims or ENVE 29XC rims, both with Stan’s sealant.
If I had written this post a week ago, I would have told you that I had never flatted…even after pounding tire-first into a hard concrete lip during a creek crossing…but I flatted last Saturday. A nasty little stubby drywall screw went right through the tire. The Stan’s tried to seal it, but I hadn’t refreshed the Stans in about 6 months, so I limped home, thew some fresh sealant in (through the valve-stem), pumped it up and was good to go. Had I been doing regular sealant replacement, I wouldn’t have had any issues. (The Stan’s has now sealed and has been problem free for the past 100 miles).
With my current 38/34 setup, I vary pressure based on conditions. Up front, my pressures for wet or mud / gravel / road would typically be 30-35 psi, 40-45 psi and 50 psi, respectively. In the rear, it’s pretty similar, but usually 3-5 pounds higher than the front. Most of the time, I run 40 psi up front and 45 in the rear. I weigh about 150#, plus bike and gear.
Tire wear on these varies greatly by location. Up front, with the 38, the front tire will last several thousand miles and will outlast 2-3 rear tires. (When I was running 38/38 on the Vaya, I could rotate and stretch both tires out). In the rear, depending on conditions, they’ll last typically around 2,000 miles, and up to about 3,000 miles. Riding higher pressures on road wears them much faster. What I typically see is a very significant amount of wear in the first 500 miles, as the center tread on the rear wears quite rapidly, and then slow, even wear from then on in. I’ve been riding the Moots on a lot of surfaces lately, getting ready for some anticipated long rides next spring, and the pavement miles show with the stripe down the center. You can run lower pressure and even out the wear on pavement, but they’re not quite as responsive then.
These are, in my opinion, the best tubeless gravel tires on the market. For pure mud, I’d pick something more aggressive. For pure road, I’d pick something with a continuous center tread for better treadlife. But for a combination of speed, traction and durability, the CX0s are my favorite. There are tires that are longer-lasting, certainly. I’ll take the tradeoff of a little faster wear, in exchange for how light and quick rolling these are. In terms of durability, as noted above, other than an errant screw, I’ve never had a flat. They’ve been perfect running tubeless, and have never let me down. That includes doing some drop-bar single track, riding really rough gravel, and riding a lot of other varied conditions.
Even as the center tread wears, the side lugs are very helpful on loose gravel and sand/mud. In soft conditions where the tire sinks in, those side lugs help the tires self-clean and dig through to something solid. These are 38/34mm wide, so they’re not floatation tires, but at low pressures, they acquit themselves admirably under soft conditions, and show good conformity to uneven surfaces. Even at low pressures, the casings are durable enough to resist flatting or problems. I will say that on hard surfaces, at low pressure, the side lugs can get a little squirmy and cause some handling irregularities. That issue can be solved by either running appropriate pressure, or by backing off a bit in corners when running super-low pressures.
I can’t really say that there’s anything I’d change about these tires, nor is there a reason I’d try another tire. They’ve proven to be bomb-proof for my riding. They’re incredibly fast-rolling and efficient. They’re great in a wide variety of conditions, which is what I’m looking for in a tubeless gravel tire (because I’m not swapping out tubeless tires for different conditions). Would it be nice if they were longer wearing? Absolutely…but I wouldn’t want to sacrifice how fast they are or how good of traction they have in the name of longer treadlife. If I want maximum miles, I’ll run some Schwalbe Marathon Mondials…but on my Moots, I want something faster.
So if you write me and ask for a recommendation for a gravel tire, if you need something in the 34 or 38c realm, this is where I will point you. They’re truly a fantastic tire.