Let me first preface. This has worked for me, and my personal riding where I live in Vermont. This is my experience.
I have fully embraced the 27.5 fat. But took it to another level by mounting my 4.0s on 40mm rims. Why 40mm? Because I had them laying around after a rebuild with my Hightower to 29er wheels. So my buddy and I relaced my fat i9 hubs to my summer 27.5 x 40mm hoops.
Why did I do this? Because in Vermont we have tremendous winter trail usage, and most-importantly dedicated individuals who groom our summer singletrack. Those heroes get their SnowDogs, Rokons, and snowshoes into tight twisty single-track.
More networks around here are grooming in some aspect. Long gone are the days of bushwacking fresh deep powder, or sloppy slush. Thank god, because powering through that stuff in a granny gear kinda sucked. Every week more trails open with a firm hard base. That we can ride fast. Dare I say we could eve ride our skinny tire bikes on some of our networks.
Our networks seem to becoming less about float. Granted you still need some float so we don't bust through the hardpack, but 5 inch tires on 80-100mm rims seem unnecessary with our networks. Like I said, our days of bushwacking new singletrack appears to be slowing thanks for numerous trail networks grooming the summer trails.
Also Vermont winters the last few years have been spotty. We can get a foot of snow, pack the trails in, then get a heat wave for a week, then when the temps drops again, we have bare ground, ice, and hardpack (mixed conditions). Mixed is actually my favorite terrain.
How does the 4.0s on 40mm ride? The answer is awesome. They are super moto with a great round profile. They are damn light and spin up incredibly fast for our conditions. I have ridden: primo groomed, loose flour-type of dust, 3 inches of powder ontop of crust, crust, textured ice, and boot packed (the loosest of the bunch). The B Fat Minus did fine.
Definitely have to keep more air pressure in tires to keep from being wobbly on the rim (found that out first ride, my pressure was too low), however a shot of air and it made all the difference. Its finding the right balance for my weight and conditions (just like with fatter tires on beefier rims) just my margin of PSI is smaller.
Like I said, this is just my experience. If you are overnighting in the middle of nowhere where you are blazing your own path this is not a good set-up.
If you spend 95% of your time riding packed trails this set up works. New School Fat.
I have fully embraced the 27.5 fat. But took it to another level by mounting my 4.0s on 40mm rims. Why 40mm? Because I had them laying around after a rebuild with my Hightower to 29er wheels. So my buddy and I relaced my fat i9 hubs to my summer 27.5 x 40mm hoops.
Why did I do this? Because in Vermont we have tremendous winter trail usage, and most-importantly dedicated individuals who groom our summer singletrack. Those heroes get their SnowDogs, Rokons, and snowshoes into tight twisty single-track.
More networks around here are grooming in some aspect. Long gone are the days of bushwacking fresh deep powder, or sloppy slush. Thank god, because powering through that stuff in a granny gear kinda sucked. Every week more trails open with a firm hard base. That we can ride fast. Dare I say we could eve ride our skinny tire bikes on some of our networks.
Our networks seem to becoming less about float. Granted you still need some float so we don't bust through the hardpack, but 5 inch tires on 80-100mm rims seem unnecessary with our networks. Like I said, our days of bushwacking new singletrack appears to be slowing thanks for numerous trail networks grooming the summer trails.
Also Vermont winters the last few years have been spotty. We can get a foot of snow, pack the trails in, then get a heat wave for a week, then when the temps drops again, we have bare ground, ice, and hardpack (mixed conditions). Mixed is actually my favorite terrain.
How does the 4.0s on 40mm ride? The answer is awesome. They are super moto with a great round profile. They are damn light and spin up incredibly fast for our conditions. I have ridden: primo groomed, loose flour-type of dust, 3 inches of powder ontop of crust, crust, textured ice, and boot packed (the loosest of the bunch). The B Fat Minus did fine.
Definitely have to keep more air pressure in tires to keep from being wobbly on the rim (found that out first ride, my pressure was too low), however a shot of air and it made all the difference. Its finding the right balance for my weight and conditions (just like with fatter tires on beefier rims) just my margin of PSI is smaller.
Like I said, this is just my experience. If you are overnighting in the middle of nowhere where you are blazing your own path this is not a good set-up.
If you spend 95% of your time riding packed trails this set up works. New School Fat.