People make off-the-wall claims like this and I want to punch them in the face:
Literally, the only way this is possible is if the guy is so incredibly slow it doesn't matter what kind of bike he rides, 20lb XC bike, 45lb DH bike, etc. There's just no way with that much rotating mass. When you hop on your 26/27.5/29 normal bike after the fat season here, it feels like you're on an e-bike and you just zoom ahead with every pedal stroke. You think you are going ludicrous speed uphill comparatively.I might see a dozen days out of the year where there is snow on the ground, however I've never really ridden in it. I'm also considerably faster on the fat bike over 29er HTs. A big portion of this is the cornering traction. Another plus is I still get the hardtail ride with the fat bike, but my body is less beat up after longer rides. If it never snowed another day here, I'd still stay on my fat bike.