Fat Bike Tires on Plus Bike Rims

My amigo Thad Carson (taddyhogg) tipped me off that he’s been running the Maxxis 27.5 x 3.8 tires mounted to a set of HED 27.5 x 45mm Raptor rims on his Oddity Cycle Lime Greenis Maximus. He also shared some encouraging reports about how his set-up handled the rocky trails near KC. (KC has super legit singletrack) So when we got our hands on a set of Borealis Carbondale 27.5 x 50mm carbon wheels, we mounted up a set of Maxxis Minion FBR/FBF 27.5 x 3.8 tires, to check it all out. The result is a tire that sits squarely in the middle of where plus left off, and where fat begins. You’re going to hear a lot about the comparison of 27.5 vs 26 this winter as we begin to see which format wins the big races. I feel 27.5 x 80mm (Low Fat) has an advantage over 26 x 80mm on dirt singletrack, but this winter, we’ll learn if that advantage extends to groomed and ungroomed snow. Currently, in my neck of the woods…..we’re waiting for snow, so it’s a perfect time to test Taddyhogg’s plus-fat setup on my black ribbon special edition Fatback Corvus FLT (photo above).

The Same Tires on different width rims – Maxxis Minion 27.5 x 3.8 x 50mm (2 on the left) compared to 27.5 x 3.8 x 80mm (far right) (L-R) Widths – FBR 89mm – FBF 91mm – FBF 96mm

We also have a set of the Low Fat Maxxis tires mounted to 80 mm Mule Fut Rims so you can make a comparison between plus-fat – low-fat and fat(fat).

Fat  26 x 80 mm rims (left) compared to 27.5 x 50mm rims Plus/Fat (right) (L-R) Widths – Cake Eater 103mm – New Husker Du 101mm – FBR 89mm – FBF 91mm

The weight difference between the two sets of wheels was a mere 160 grams and surprisingly, the 26″ traditional fat wheels were lighter than the  narrower 27.5″ set of wheels. The tires spokes hubs and cassette are variables that could easily explain the weight difference and I bet that Thad’s set of HED Raptors are even lighter yet. In my head, I called it a wash, so I wouldn’t let that tiny weight difference influence my test ride. When I look at the Plus/Fat set up on my Corvus, it reminds me of the setup that Sven always ran on his singletrack optimized Schlick Northpaw. He ran a 50mm wide 26″ rim with a narrow fat-bike tire like a Panaracer Fat-B-Nimble and liked the way that the narrow rim rounded out the silhouette of the tire and spread the shoulder knobs out wider than the tire casing. That’s the exact effect that the 50mm wide 27.5″ rims have on the Minions.

I mounted the tires, tubeless and they held air overnight. I aired the tires down to 11.5 psi front and back and took it out to the John Muir Trails at the Southern Kettles. I expected it to be fairly saucy out there, but most or the trail was frozen dirt. There were spots where the sun had melted the top layer of soil, and those spots were pretty greasy. Maybe about a third away around the Green Loop, I stopped and bled a little air from the front tire. This setup reminded me of riding the Heller Bloodhound Trail (which comes with a 27.5 x 80 mm wheelset). I started thinking about how I could probably fit this set-up in a Fox Suspension fork and add a dropper post for summer singletrack riding. These are the thoughts of a happy brain, because I loved the way the bike rode with this setup. It felt more like riding a 29r mountain bike, but with the stability of wider tires. I’ll need more time riding in looser conditions, but my initial impressions are pretty positive. I’ll be riding these wheels until the snow flies and conditions require more flotation. I suspect we’ll have much more to say about wheels sizes, during segments of our podcasts over the winter, so stay tuned for the ever popular – more – somewhere down the trail.