Over the last few years the fatbike has gained a lot of popularity and people don’t use the bike for winter riding only anymore. This big wheeled bike has become a fan’s favorite for summer rides too, a big tire bike is no longer a rare sight on the trails. As the bike gets ridden all year round now, tire choice adds an important factor to the driving experience.
Fat tire explained
A fat tire is a much wider tire than a regular MTB tire. A normal tire has a width between 2.0 and 2.6 inches as where a fat tire is much larger, usually between 4 and 5 inches wide. The bike still uses a 26 inch wheel to seat these enormous tires. Also the width of those rims are much wider, going from 75 to 100mm instead of 20 to 40mm on regular tires, but due to the volume of the tire it feels like you’re riding a proper 29 inch bike. You’ll even notice when comparing a fat tire and a 29 inch tire, the outside diameter will be larger than the regular wheel.
To get the best experience from your fat tire you’d want to set it up on a very low tire pressure, between 5 and 15 psi. This way you can get maximum grip and still have this floaty feeling on the bike. This big aircushion gives you the ability to plow through snow or sand without any problems. It gives great damping, it takes away a lot of chatter you’ll come across on the trails like roots, rocks and small bumps. If your tire is pumped too hard you’ll lose all the driving characteristics of a fat bike, but a tire that’s too soft will have a lot of sidewall flex. It’s up to you to find out what tire pressure is ideal on your local trails.
Fat tire vs plus tire
One of the most important things to check when choosing a tire for your fat bike is the clearance. You’ll have to determine if your bike can handle the chosen size of tire and wheelset.
Nowadays it’s not uncommon to have an extra set of wheels for your fat tire cycle as it’s used all year round. People tend to have a wheelset for summer and a wheelset for winter riding. And there are a couple of options to choose from:
26 inch wheelset with a fat tire
27.5 inch wheelset with a fat tire
27.5 inch wheelset with a plus tire
29 inch wheelset with a plus tire
The 26inch wheelset is what a fat cycle is made for, so you can perfectly switch the tires only between seasons. This is bit more work intensive than having two different wheelsets, definitely if you ride tubeless, but it will be the cheapest option.
The tire choices in itself depends on what you need. A large, knobbed tire with a lot of grip for the rougher trails or weather conditions or a better rolling tire with smaller and more spreaded knobs for summer riding and more loamy trails.
Keep in mind when you put on a large tire or a larger wheelset, the height of your bottom bracket gets raised. Because, as mentioned before, the outside diameter of a 4.0” or even a 4.5” tire will be much larger than a regular 29 inch wheel. Some riders put a 27.5 inch fat wheelset to raise even higher their bikes but doing so will also make your bike feel more sluggish. Because of the bigger tires you’ll have to work harder in those turns.
Then there’s also the option of a 27.5 inch or even a 29 inch wheelset with a plus tire. Although the latter is not commonly seen on a fatbike. To be clear, a plus tire has a width between 2.8 and 3.2 inches wide.
The use of a plus tire on a big tire bike is to make the bike more responsive compared to the fat wheels due to the weight difference between both wheelsets. Although you’ll be losing a bit of the damping abilities of your fat tire, your bike will gain more acceleration certainly coming out of those slow corners.
When you choose for a second pair of wheels for your fatbike you need to look into a new wheelset. Although the market is a bit smaller than regular bikes, still there are many options to choose from.
The first decision is all about wheel size. The most common choices are a 26 inch or a 27.5 inch wheelset on fatbikes.
The 26 inch wheelset feels a bit stiffer than a 27.5 simply because the spokes are shorter. And due to the larger clearance it can accommodate a larger tire on the rim. Also since it’s smaller there is less of a weight penalty but as these wheels ar made for fat tires you’ll have to take the weight of the chosen tire in consideration.
A 27.5 inch or a 29 inch wheelset gives the possibility to fit a different sort of tire with less rolling resistance. As mentioned before, there will be a bit more flex on the wheels compared to a 26 inch. But if this is a nuisance for you as a rider you can always opt for carbon rims. A carbon rim will give you the necessary stiffness and is a lot lighter than aluminum wheels making you more nimble on the bike, less fatigued and going for longer rides.
90c 26er fat bike wheels
What choice do you need to make?
To me your fatbike wheels and tires depend completely on your riding style and the conditions you live in. If you use your bike to commute everyday my weapon of choice would be a 27.5 plus wheelset but if you use your big burly bike to shred through rough terrain I’d choose a 26inch wheel with a nice fat tire on it. I wouldn’t want to lose all the advantages and fun to ride a fat bike on the trails even if this means I’d have to pedal just a bit harder.