This where it’s won and lost as cornering is often the defining line between having fun and hitting the ground. The Bontrager XR4 corners like a champ. It is consistent, predictable and it grabs a hold of the trail with authority. We ride a lot of loamy, bermed singletrack so we actually had to make the effort to ride loose terrain for the sake of tire testing. For hero dirt singletrack, these tires grab with more to spare. In fact, we actually preferred putting the more XC XR1 tire in the rear just so we could slide the rear a bit and throw the bike around more.
On loose fire road, these tires hooked up. We used the Team Issue as the gummy side knobs were really able to find side traction where it was scarce. We believe that the supple casing also helped this tire hook up in the rocky, loose trails of the Kennedy trail in Los Gatos, CA. The siping or cuts on the knobs of the tire seemed to help too as this tire was hooked up as we pushed it a little on some off camber turns.
Wet and Mud abilities
Again, this tire did very well. The open block pattern of the tire allowed it shed mud pretty well. Wet rocks and roots are pretty daunting but this tire with the soft casing and soft side knobs kept us upright.
Again, it seemed to roll pretty well. It’s not a race tire for sure but it never felt like a slow tire like the old Nevegal. For fast Strava runs, we put the Bontrager XR1 in the rear for speed and the XR4 in the front for traction. Braking and climbing traction was excellent in all conditions for us.
Durability and Tubeless.
The tires came through with flying colors for us but we don’t have a ton of sharp rocks here in Norcal. For tubeless, Michael Browne sent us some TLR (tubeless ready) versions and we pumped those up tubeless with no issues whatsover. We put some Stans fluid in and the setup never leaked.
We’re pretty darn impressed so far. The tires will definitely bring the best out of any Trek bike and we believe this can be a great component choice for any bike brand. If you have an All Mountain ultimate bike build, definitely take a look at these. If you want a balance of speed and grip, put these in the front and put the XR1s in the rear. 29er or 26er, these tires are a good choice.
We’ll keep riding them throughout the season and update this review.