My Mongoose Dolomite ALX fat bike came with knobby Arisun Big Fatty tires. They are decent enough, and they are probably well suited to loose dirt trails. However, they are fairly noisy on pavement, and I don’t really plan to ride dirt trails that much with my fat bike. Looking around, the fat tire most praised for street use seemed to be the Origin8 Supercell. I ordered a pair of the 30 TPI tires, which are evidently heavier and stiffer but more puncture resistant, and I put them on my bike today.
They are definitely quieter and smoother. I think I can tell that the rolling resistance is less, but I’m running them at higher pressure right now, so it’s not a direct comparison. I rode 8½ miles with them on my first test ride.
Overall, I like them, and they are an improvement, but I’m not sure they are enough of an improvement to justify the cost.
Fat bikes have a phenomenon known as self-steering. Because the tire is so wide, leaning into a corner causes the contact point with the pavement to shift noticeably away from the center plane of the tire. This makes the turn feel different than expected. It is known as “self steering” because it causes the bike to seem like it has a mind of its own.
Reviews of this tire have suggested that this tire is particularly bad about self-steering. I have read two solutions. One came from the manufacturer, which is to inflate the tire to the full 20 PSI that it can handle. Another reviewer suggested that the self-steering went away after he put a few (ten) miles on the tires.
For my initial test ride, I inflated the tires to 20 PSI. The self-steering was imperceptible to nonexistent, whereas the Big Fatty tires that came on my fat bike had a quite significant tendency to self-steer.
I’ll update here after I try it, but I’d like to reduce the pressure to 8 PSI in the front and 10 PSI in the rear, break then in for ten miles, and see how they ride then.
Update: I tried lower air pressure. I had taken the wrong pressure gauge with me, so I couldn’t lower them to a target pressure, but I measured them at home: 6¼ in front and 7¾ in the rear. The amount of self-steering was astonishing; far, far worse than what I ever experienced with the Big Fatties. There’s no way breaking them in could solve this. So, 20 PSI it is for these tires.