Plus-size wheels and tires are a hot topic in the mountain bike industry, and while there’s no clear consensus on where all this is heading, I’m personally interested in seeing 27.5+ conversions for regular old 29ers. So I was stoked to get my hands on a pair of 3.25-inch VEE Trax Fatty tires to see if they would work with my rig.
VEE offers multiple flavors of the Trax Fatty, which is itself just a fatter version of the regular Trax tire. The Fatty comes in both 27.5 and 29er sizes and the 27.5 can be spec’d with 72 or 120tpi casing and either the single compound or silica compound. I’m testing the silica, 120tpi version which weighs a claimed 800g per tire. The packaging is notably awesome, made up of an octagonal cylinder with a large V-cutout and the VEE logo wrapping around the box.
Aaron worked with Chris at Loose Nuts to mount these tires tubelessly to a pair of WTB Scraper 45mm rims. I’m sure 27.5+ tubes are coming (if they don’t already exist), but no biggie because the Trax Fatty tires air up just fine with a double dose of Stan’s in them. Initially we had trouble keeping air in the tires but once I bounced the wheels around on the trail a bit there were no issues.
Unfortunately, these tires were a no-go on my Santa Cruz Tallboy–the rear triangle is just too narrow. I was able to jam the front tire in my Fox 32 fork but there was literally no room left on the sides for the wheel to spin. As far as 27.5+ conversions go, this tire really isn’t a good choice and I doubt it will fit many (if any) standard 29er forks / rear triangles out there. However, VEE offers this tire in both 2.8-inch and 3.0-inch widths, which should be much more conversion-friendly.
To test this tire we turned to the one bike we knew these tires would fit: Tyler’s Surly Krampus. The Krampus is a 29+ rig so the tire height wasn’t even close to being an issue. And while the Krampus is typically paired with a 3.0-inch 29er tire, the fork and rear triangle had no issues accommodating the 3.25-inch VEE Trax Fatty. Note: running 27.5+ tires on a 29+ bike isn’t ideal–the outer tire diameters are significantly different and this change will affect the bike’s geometry (most notably bottom bracket height.)
On the Trail
Many fat bike tires (and to a lesser degree, plus-size tires) skip out on traditional side knobs, perhaps because lower pressures keep the center of the tread in better contact with the ground (ditching side knobs also means lower weights). However, the Trax Fatty tire tread more closely parallels traditional mountain bike tires with a defined center tread, transition knobs, and side knobs.
I pumped the front and rear to about 25psi, which may cause some readers to scoff–but IMO, the tread on this tire is begging to be railed, not flopped. On the trails, the Trax Fatty was a rockstar. On a slippery pine straw-covered sidehill, the tire held its line with aplomb. Over greasy roots, the Trax Fatty kept its composure even in the climbs, providing surprising purchase on the steeps. In deep mud bogs, the tire floated above the mess, leaving behind a smooth ribbon of sculpted mud in its wake.
Speaking of mud, the Trax Fatty does an excellent job at shedding mud. The tread itself is pretty deep but the knobs have plenty of room to breathe. I haven’t put a ton of miles on these tires but just judging by feel, the compound seems to be fairly sticky–great for greasy or snowy trails but fast wearers on rocks and pavement.
The 120tpi silica Trax Fatty I tested retails for $120 while the 72tpi, wire-bead single compound goes for $100. With a more traditional mountain bike tire tread pattern, a grippy compound, and excellent mud-shedding abilities, this is a great choice for your 27.5+ all-rounder build. If you’re thinking of including this tire on your 27.5+ conversion, your best shot is to go with the 2.8-inch version.
Thanks to VEE Tire Co. for providing these tires for review.