There is really no repeating this or defeating it either, there are way too many choices available and not as many reviews, at least not those that matter. The every evolving bike industry has left us with options bizarrely similar to each other with small and simple modifications separating them. The fat bike vs mountain bike example is not exclusive to it either. 

Fat bikes and mountain bikes are similar in many ways except for one little difference. In fact, fat bikes are basically mountain bikes but with fatter tires. If you thought mountain bikes have fat tires, you are not ready for fat bikes. Fat bikes have tires with widths that could fall anywhere between 3 to 5 inches. On paper, this does not seem like a lot, but it sure is. Fat bikes are the monster trucks of bikes. If you are riding a fat bike, anywhere, whether it be a mountain, the street, just potentially anywhere, you will turn heads and be the subject to some really weird glances. 

Now while fat bikes are essentially a modified version of mountain bikes, let us weigh all the pros and cons to get to the conclusion on which one is better than the other, or at least for you to look at them and figure out which one is better for you. Modified, almost always is synonymous to better because the modifications were made to make the bike better, quite literally. 

However, the bike industry has been susceptible to some epic upgrade fails and a lot of big brands are to blame for it. What I am about to do is show you all the upsides, the downsides and the differences for you to decide the better pick for you. 

Differences Between Fat Bike VS Mountain Bike

Size of tire

The first major and very obvious difference is the size of the tire. Fat bikes have tires twice as big as mountain bikes. This was as a result of an evolution of mountain bikes. Now there is no way to identify pole differences between the two other than the tires so this remains the only major difference between the two. 

Seasons of use

The obvious advantage that fat bikes have over mountain bikes? Fat bikes give you an all season pass to riding your bike. Fat bikes because of their tire width, give you greater traction. Greater traction means greater control and no slipping all over the place. This means you can ride fat bikes in snow and sand alike. 

So even if you live in the middle of the Sahara desert(which is unlikely but we will consider this right now) or in the middle of a region almost always under a snowstorm(also unlikely, but moving on), fat bikes have got your bike. Mountain bikes were modified into fat bikes for this very purpose, to make them usable in all seasons unlike their parent design, aka, mountain bikes. So if you live in a region that has extreme weather conditions and you can picture yourself wanting to ride a bike on a snowy day, fat bikes are your best bet. 

Traction

I think this is also a pretty obvious upper hand that fat bikes have over mountain bikes since this was the reason for the modification. Fat bikes because of their chunkier tires, have greater traction when put in comparison to mountain bikes. For those of you, who do not know what traction means, traction is basically the friction that is formed between the tires and the ground, resulting in a sort of attraction between the two. 

Because of traction, your bike stays mounted on the ground and does not keep slipping all over the place. This is what it means in non-technical terms for it to be easier for you to understand whether or not you are looking for this particular feature to be in your bike. 

Speed

Mountain bikes win, fair and square. Speed has two main influencing factors, weight and fluidity. Weight and speed are inversely related. Therefore, greater the weight, lesser the speed. Fat bikes, as the name quite non-discreetly suggests, are fat because of their chunky, enormous tires. When put in comparison to fat bikes, the generally chunky considered mountain bikes, weigh less. 

Most of the weight of fat bikes is contributed by their tires and if you switch those out then technically you change the bike type completely. The weight ratio alone, makes mountain bikes heavier than fat bikes. Another thing that plays against the speed of fat bikes is the amount of friction that is created between the ground and the tires. Friction and speed are also inversely related, greater the friction, lesser the speed. The width of the fat bike tires, makes it have greater fiction. Because of these two aspects, mountain bikes are significantly faster than fat bikes. 

Strain

Fat bikes take another win. When it comes to uphill climbing there are literally no other bikes that could defeat fat bikes. Fat bikes have a massive amount of traction working with them. What this essentially does is take off all of the load from you and push your bike forward on the basis of traction alone. 

Uphill riding can be difficult for a lot of people and if that is a problem that you face and want to fix, fat bikes are easily the best possible solution to it. The pressure on the tires does all the work while you have to do the bare minimum. 

Comfort

With fat bikes, especially on rough terrains, it literally feels like you are floating on nothing and definitely not on a road full of pointy rocks. While mountain bikes also specialise in the same department, fat bikes have seemed to one up them. Fat bikes have chunkier tires when put in comparison to mountain bikes which is the whole basis of difference between the two. 

Chunkier tires mean more comfort. This is because the volume and pressure inside the tires absorb l of the bumps and barely any energy reaches the frame, let alone the saddle. So if you are looking for comfort then fat bikes are the way to go. 

Versatility

Fat bike frames, aka, the wheel rims accommodate both fat bike tires and mountain bike tires. So in case you feel like you do not want to ride a fat bike to whatever place you want to go, you can easily switch those tires out for mountain bike ones. This is almost like having two bikes in one and versatility is always a welcome feature when it comes to bikes. 

Mountain bikes on the other hand, have a very rigid frame that is meant to go with very specific parts, giving it almost no points when it comes to versatility. 

Resistance/Hesitation

Fat bikes because of their abnormally huge tires have greater traction as discussed before. Now this could sometimes prove to be a bad thing. When riding on smooth concrete pavements that do not have a lot of texture going for them, the traction on fat bikes gets converted into resistance or hesitation that you might experience while riding the bike. 

The same thing does not happen with mountain bikes, sure they are not the same as road bikes but the lowered level of traction and the build of mountain bikes make them better suited for the streets/concrete pavements. 

Cost

Now this is a difficult category to judge as in both mountain bikes and fat bikes there is a huge gap between the lowest costing bikes and the most expensive ones. Both of the bikes could cost you a fortune or a negligible amount. All things considered both the bikes fall under a similar pricing spectrum depending upon what bike you choose to buy. But if you consider the fact that fat bikes can technically change into mountain bikes just by changing its tires, you basically are getting two bikes for the price of one. 

From that perspective fat bikes definitely win and are the better choice. But if tire changing is not something you are keen on, they both have a similar price range.

Let’s have a final list of pros and cons to decide which one wins(sort of):

Fat Bike

Pros

• Greater traction
• All season riding
• Versatile
• Comfortable
• Causes less strain

Cons

• Slow
• More resistant on smooth surfaces

Mountain Bike

Pros

• Fast
• Less resistant on smooth surfaces

Cons

• Lesser traction
• Can only be ridden in specific seasons
• Rigid design
• Less comfortable
• More strain while going uphill

Conclusion

If we consider the pros and cons list alone, then it is pretty clear that fat bikes are a better choice in comparison to mountain bikes. However, what is best for you, depends on what you prefer and where and how you want to ride your bike. There are no rights or wrongs when it comes to biking it all boils down to liking. Hopefully, all of this information laid out gave you clarity on what might be the best pick for you.