WTB Trail Boss Tire
Stated Width: 29” x 2.25”
Actual width on WTB Frequency Team i25 rims: 2.2” (56mm)
Versions Tested: (a) TCS Tough and (b) TCS Light
Blister’s Measured Weight:
- TCS Tough: 1038 grams
- TCS Light: 780 grams
Mounted to: WTB Frequency Team i25 rims on a Canfield Yelli Screamy
Intended For: Fast rolling + Traction
Duration of Test: About 2.5 months
Locations: Primarily in and around Whitefish, MT
Reviewer: 5’9” 155 lbs
MSRP: $39.95 – $79.95 ($69.95 and $79.95 as tested)
WTB has been rolling out a few new tire options in the past year or so, including the Vigilante (in a couple of different casings) that I reviewed last spring.
The Trail Boss bears some similarities to the Vigilante, in that it has a bunch of more or less square knobs with some siping. This is something of a departure from the tires we’ve seen from WTB in the last few years, which tend to be busier and have lots of buttressed, non-square knobs.
In my humble opinion, this departure is a good thing; I got along pretty well with the Vigilante, and for a lot of the riding I do on my Yelli Screamy, I like the Trail Boss even more.
Sizes and Options
The Trail Boss is offered in two widths: 2.25”, and WTB has now added a 2.4” option. My 2.25” version measured 2.2” on a 25mm (internal) rim.
Both widths of the Trail Boss come in two wheel sizes, 27.5” and 29”. Unfortunately, there is no 26” option.
But more interestingly, it comes in three different versions: TCS Tough, TCS Light, and Comp. And within each version, there are a couple different casings and tread compounds.
In the Tough iteration, the Trail Boss comes in two different rubber compounds, High Grip and Fast Rolling. The High Grip option features WTB’s “Gravity DNA” compound, which is a 45a durometer tread with a 60a durometer base. The Fast Rolling option has WTB’s “Dual DNA” compound, which has a 60a durometer center tread and a softer 50a durometer side knobs.
The Tough uses WTB’s Enduro casing, which has two layers of bead-to-bead 60 tpi casings. Holding this tire in my hand, the Enduro casing is essentially a full-blown DH tire (although it still has a folding bead). The casing is thick, stiff, and feels like it’d take a substantial amount of abuse.
TCS ‘Light’ and ‘Comp’ Casing
The Light version of the Trail Boss has, unsurprisingly, a lightweight 60 tpi casing. This casing doesn’t have any additional reinforcement in the sidewalls, and is similar to most other “normal” folding bead tires.
I didn’t get an opportunity to play with the Comp version, but it comes with a wire bead and isn’t intended to be run tubeless. The upside is that, at $39.95, it’s fairly affordable.
Both the Tough and Light versions of the Trail Boss come with WTB’s TCS system, (which is redundant since TCS stands for Tubeless Compatible System).
TCS means that the bead profile on both TCS-compatible rims and TCS tires are UST compliant. These are not UST compliant in the sense that you don’t need sealant (you do), but they also don’t come with the significant weight penalty associated with full UST tires.
Really, what “TCS” means is that the tire bead dimensions are designed and manufactured to match closely with the rim dimensions, and the bead locks into the rim pretty tightly.
This is a good thing; tubeless setup is basically the same as with any other tire using tape and sealant, but it means that its relatively easy to get the bead to seat (I did it without a compressor, no problem), and it means that it’s quite a bit harder to get the tire to “burp” in hard corners and on sketchy landings.
While TCS tires will work fine on non-UST certified rims, and WTB’s TCS rims will work fine with tires that don’t have UST bead dimensions, running TCS or UST tires on TCS or UST rims just means that you’re getting the most out of the design.
While I only ran the Trail Bosses on WTB rims, I spent some time on the WTB Vigilante mounted on a Stan’s Flow EX, and noticed that it was easier to get the tire to burp on the Stan’s than when I had the same tire mounted on the WTB rim.
The Tire Design
The Trail Boss has a relatively tightly spaced alternating set of knobs in the middle, and pairs of square knobs that are placed at a mild angle along the sides of the tire. Every single knob on the tire has a single sipe down the middle, with the center knobs siped laterally and the side knobs siped longitudinally.
I talked a bit about transition knobs in my Vigilante review, and the executive summary is that knobs that fall in between the center knobs and the side knobs can help cornering at moderate lean angles, but they often prevent the side knobs from digging in properly when the tire is really leaned over.
While the Trail Boss’s center tread blocks are fairly wide, there aren’t really any knobs that I’d describe as transitional. There isn’t a broad channel between the center knobs and the side knobs, as there are on the 45 North Nicotine, but there’s still a pretty clearly defined separation between the knobs down the middle and knobs along the sides.
I should also note that, while I haven’t (yet) ridden the 2.4” version of the Trail Boss, the channel between the center knobs and the side knobs grows significantly wider. Basically, the knobs more or less stay the same size on the 2.4” version as on the 2.25”, which means the gap between the center and side knobs grows by around .15”, which, just looking at the tire, is a very noticeable amount).
The knobs on the Trail Boss are a bit lower than on a meatier tire like the Vigilante. In theory, this helps the tire roll a little faster, and it also keeps the knobs from feeling squirmy (i.e., like the knobs are folding over) in the corners. The downside is that it means they won’t dig in quite as much when the going gets soft. All of the knobs are the same height; the side knobs don’t stick up above the center tread.
While tire shape depends quite a bit on the rim they’re mounted to, I wouldn’t say the Trail Boss has a particularly square profile, despite the 25mm internal width of the WTB i25 rim I was running.
On the spectrum of round to square tire profiles, I’d put the Trail Boss somewhere right in the middle—not super round, but not particularly square, either.