Terrain Targeted Tires

What’s In A Name?

I wanted to start this out with some play on words, mixing up XTC’s debut album “Drums and Wires” with the words “valves and tires” because that is still such a damn good album 45 years later, and because it sorta almost works as a rhyme, and because this is a review of some valves and some tires, but I just couldn’t connect it in a way that would have made any sense to a search engine. Still, damn that was a good album.

Aaaanyway, what we have here are a couple new tires from Trek. For the longest time, Trek’s Bontrager branded tires have used an alphanumeric naming convention that did the job of differentiating each tire from the next in the chain, but was not very evocative in that descriptive way that marketeers like. So, this year the Bontrager mountain tires are undergoing not just a design change but a naming overhaul. This applies to the XC and trail tires, primarily. So, out go the old XR1, XR2, SE3 and SE4, and in come the new Vallnord and Sainte-Anne XC tires, and the new Montrose and Gunnison trail meats. The names of the tires are intended, presumably, to denote appropriate use-case terrain for each of the new designations. Living as I do now in the same soil type and relative geographic proximity to the Colorado towns of Gunnison and Montrose, it seemed like an opportune time to see how the new Gunnison and Montrose stack up.

Word Salad

Before we get into the individual tires, let’s dig around in the change in naming convention. Aside from the tire model descriptor going from robotic to romantic, there have been some changes with the casing and compound descriptors as well. The outgoing tire models existed in a three-tier Comp/Expert/Team “good/better/best” structure. That has now expanded to four tiers – Comp, Elite, Pro and RSL. Three prior constructions – XR (trail), SE (enduro), G (downhill) – have also been amended to four: XR (XC), XT (trail), SE (enduro), and G (downhill). XR casings are the lightest, featuring some sidewall protection. XT get 120tpi construction butyl apex pinch flat strips and bead to bead protection, SE uses a 60tpi construction, bead to bead protection and extra sidewall armor, and G is a full-on double casing DH carcass.

Bontrager sent out a pair each of the Gunnison and Montrose, both 29x2.4 and in the same RSL XT designation. These being their top flight offering in each model utilize a triple compound with a hard base (67a), medium center-top (60a) for climbing and braking grip/longevity, and soft (45a) outer shoulders for corner read and more traction. Both of these top of the pyramid tires retail for a reasonable $70US. Dropping down a level to the Pro XR model loses the butyl-apex pinch flat protection and goes from triple to a medium/soft dual compound, and also costs $20US less.

Both the Gunnison and Montrose were tested back to back alongside a couple sets of control tires – 29x2.4 Specialized Purgatory T7s, and a Maxxis Aggressor rear 2.3/Dissector front 2.4 combo – all at 25 psi.

Gunnison

This, in Bontrager’s words, is “an all-round trail tire that provides grip and speed in mixed conditions from rocky desert to high alpine.” Weighing in at 1024 grams for the 29x2.4 size, it sits squarely in the same size/weight/intended use landscape as the aforementioned control tires. The Gunnison is not designed to be a shore-centric tire, and as such I cannot comment as to how it might work anywhere wet or slippery, but the terrain I have been riding it in is exactly where it was designed to be ridden, so here goes.

Visually, the Gunnison profile is very similar to the Dissector and Purgatory and the side knobs look on par, albeit with slightly less sidewall height and overall volume, but the ride feel is rounder, for lack of a better descriptor. It took me a few rides to begin to trust the front when dropping into turns. There was just a tiny moment of vagueness when tipping in, especially on loose ground. But the thing is, it didn’t let go, and once I got used to it, I was able to push it into the ground and it would stay tracking just fine. When it did let go, it usually telegraphed what was happening well enough to react and correct. Comparing it to the taller, more aggressive Dissector up front is tough. That is to say, the Dissector was designed for/by an Australian DH pinner and is a really good cornering tire on dry, hard, skatey ground. What is it they say about comparison being the thief of joy?

Anyway, the Gunnison rolls on par with the Maxxis/Specialized competition, but the construction feels a little more cushioned/damped for a given pressure. This was a very pleasant surprise. While it might not be the most confidence inspiring at first in loose corners, it is super supple and calm when tracking through chunder and pulling traction on ledgy climbs, and it lends a feeling of control that enhanced the overall ride of my bike. The comfort level is welcome when riding in a landscape of chattery junk, and running Gunnisons front and rear made me feel like my suspension had gained a touch more small bump responsiveness. The trade-off to this supple smoothness is that the rear does squirm and flex a little bit when reefing up the face of slabs. The same could be said for most of the other super tacky high-grip compound tires in similar situations. No knobs tore off in five rides, though, so that’s a good sign.

Montrose

Pulling the words from the marketing horse’s mouth again, the Montrose is “a fast rolling trail tire with the trifecta of grip, speed, and durability for versatile performance in generally hardpacked dirt.”

Well damn howdy, they got the speed part right! Compared to the Gunnisons, as well as the control tires, these things feel like rockets. Okay, so at 985 grams the Montrose weighs about 40-50 grams less than the Gunny, or the Dissector, but it rolls out like it weighs a couple hundred grams less than that. Repeatedly, on a mile long stretch of slightly climbing dirt road, for a given heart rate I found myself riding a cog or two smaller, and between 1-2mph faster. It was noticeable wherever the ground pointed up and anywhere that quick acceleration was needed. The Montrose gets after it.

With smaller knobs overall, and less shoulder in particular, I was concerned that traction would suffer, and would totally negate all that awesome pedaling speed. To a small degree, this was the case in loose ground, whether sandy or kitty litter. On slabs and hardpack however, I came away impressed with not just the traction, but the readability of the Montrose. Smaller knobs meant less squirm and a more direct, more immediate communication between me and the ground. It also hung on admirably when smearing laterally across angled slabs. Smooth turns were similar – sharp handling, lots of read and surprising levels of grip. As the going gets looser and rougher, the limitations begin to show up. Even though it has the same casing and volume as the Gunnison, the Montrose feels smaller, harder, and less forgiving in rough terrain. It’s not designed as a high volume rock smasher, so expecting that is maybe going beyond the design intent, but I was very impressed with how well it behaved all the way up until that threshold.

TL/DR:

For high alpine singletrack that leans more toward smooth than gnarly, I’d pick the Montrose over the Gunnison all day long, and would rate it as very worthy of consideration when looking for a versatile, capable summer tire that pedals well but can handle a lot more terrain than the limited XC-oriented treads. If the diet is going to be primarily chunk and gnarl, then the Gunnison would be a better call than the Montrose. But that said, when it comes to chunk and gnarl, there are a lot of really good tires out there, and the decisions get tough. I’d say the Gunnison would be somewhat outgunned by the Minions and Dissectors and Butchers of the world, but it rolls better than them. And for the most part, it costs less too. Choose accordingly.

High Flow Valve Adaptor

Finally, check this little puppy out. It’s a high flow adaptor that screws onto the top of your existing Presta valve, replacing the core with a fitting that flows more air and is less prone to getting gunked up with sealant. According to Trek, it flows three times as much air as a standard Presta valve. The cap even comes with a Presta core remover built into it.

At $25US a pair, this represents a midpoint between the $1-2 a pop cost of a regular old fashioned Presta core and the $50US cost of a pair of Fillmore valves. Compared to $2, it’s expensive. Compared to $50, such a bargain! You don’t necessarily benefit from the extra design that goes into the bottom end of a dedicated high-flow valve, but you do get rid of the traditional finicky Presta choke point AND blow a lot more air through the hole than before. So far, these are working as advertised, but I can’t verify the 300% airflow bit. The only concern I have about them is that if you end up threading one onto an already tall valve stem, this will make it taller. Aesthetics aside, I’ve had two instances in the past five years where an errant rock has deflected up off my front wheel and managed to snap off a fancy alloy Presta stem. If that happens out on the trail and you’re not packing a spare Presta valve, you are screwed. This could potentially increase the size of that random potential rock target. I know, what are the odds?