Fat bikes are becoming an increasingly popular alternative to mountain bikes for off-road riding and bikepacking. They are fun, unique, and allow you to ride places that no other bike can go, like deep snow and loose sand. This guide outlines the pros and cons of riding a fat bike vs mountain bike to help you decide which type of bike is best for your style of riding. I’ll also outline a few important considerations when choosing a fat bike and mountain bike.
What is a Fat Bike?
A fat bike is an off-road bicycle with extra-wide tires that generally measure 3.8” (96mm) or wider and rims measuring 2.6” (66mm) or wider. The frame, fork, and wheels are also specially designed to accommodate the wide tires. Fat bike tires are usually run at an extremely low air pressure of 5-14 psi.
The goal of the wide tires is to distribute the weight of the bike and rider over a larger surface area than typical bike tires. This reduces ground pressure so you can float over soft or unstable surfaces that normal mountain bike tires would sink in and get caught up. Fat bikes were invented for riding on deep snow and soft sand. They also perform well in mud, bogs, loose gravel, and desert environments.
The soft, low-pressure tires deform around obstacles like rocks, ice, tree branches, and potholes, instead of getting caught up or bouncing off. This reduces bumps and vibrations and generally makes for a smooth ride.
What is the Difference Between a Fat Bike and Mountain Bike?
The main difference between a fat bike and mountain bike is the width of the tires. Fat bike tires measure 3.8″-5.2” wide (96-132mm). For comparison, standard mountain bike tires measure 1.9”-2.6” wide (48-66mm).
In order to accommodate such wide tires, fat bikes need wider rims than mountain bikes. Fat bike rims measure 55mm or wider with 65mm being the most common. Most mountain bike rims measure about 30mm wide. Fat bike rims measure 26” or 27.5” in diameter. With the high volume tires, the wheels have a similar diameter to the 29” wheels that are common on modern mountain bikes.
Fat bike frames need extra clearance so the wide tires don’t rub. To solve this problem, manufacturers make the fork arms as well as the seatstays and chainstays extra wide. This makes the hub spacing wider on fat bikes than mountain bikes. Fat bikes use extra-wide hubs that measure 170-190mm. For comparison, standard mountain bikes use 142mm hubs.
Because the tires and rear hub spacing are so wide, the bottom bracket and crank spindle need to be wider as well. This spaces the chainring further from the frame so the chain doesn’t run at an extreme angle.100mm bottom brackets and 100mm spindle cranksets have become standard on fat bikes. Some manufactures (like Surly) are switching to 132mm bottom brackets and cranks. For comparison, most mountain bikes use 68mm or 73mm bottom brackets.
Another major difference between fat bikes and mountain bikes is the pressure that the tires run at. Fat bike tires can run at incredibly low pressure of 5-14 psi (.34-.97 bar). For comparison, most riders run their mountain bike tires at 22-25 psi (1.5-2.4 bar). This is possible because fat tire are so voluminous that they won’t bottom out and hit the rim if you hit an obstacle.
A Quick Off-Road Bicycle Wheels and Tire Size Comparison
- Mountain bike tires measure between 1.9”-2.6” wide. Most mountain bike rims measure 25mm-30mm on the internal. Common mountain bike wheel diameters include 26”, 650b, and 29er.
- Fat bike tires measure 3.8”-5.2” wide. The rims typically measure 50-100mm wide. Most fat bike wheels measure 26” or 27.5” in diameter. The standard fat bike rear hub spacing is 170mm or 190mm. 135-170mm hubs are used in the front.
- Plus tires measure about 2.8”-3” wide. The ideal rims measure 34mm-40mm wide on the internal. Common plus bike wheel diameters include 26”, 650b, and 29er. This is a newer size category that has become popular in the pas 5 or so years.
A Bit of Fat Bike History
Throughout the early to mid 80s mountain bikes became incredibly popular. Riders began modifying their mountain bikes to handle snowy and sandy terrain. Modern fat biking was invented simultaneously in both the snowy backcountry of Alaska and the sandy deserts of southern New Mexico.
In 1987, the first Iditabike event was held in Alaska. This event challenged cyclists to ride the first 200 mile section of the famous Iditarod dog mushing trail through the Alaskan backcountry during the winter. Trail conditions ranged from glares of ice to crusty frozen snow to soft powder and everything in between.
Riders spent a great deal of time walking their mountain bikes through the deep snow and slippery ice. This experience challenged the riders to improve their bikes for the next year’s event. They knew they needed wider tires with a larger contact patch.
Alaskan frame builders began experimenting with various solutions. They began welding two rims together side by side, lacing them to a single hub, then installing two tires on the new double-wide wheels. They also modified frames so the extra wheels would fit. This wider footprint increased traction and float so the riders could ride more and walk less.
A man named Simon Rakower refined the invention and created SnowCat rims. He removed the inside rim walls so riders could mount a single high volume tire to the rim. This reduced weight and allowed them to run the tire at low air pressures. Riders would cut and sew two tires together to make one large tire.
Around the same time, a man named Ray Molina commissioned custom 82mm wide rims, 3.5” tires, and compatible frames so he could take tourists out to explore the Arroyo sand dunes in southern New Mexico and Chihuahua, Mexico. He called the tire the Chevron.
In 1999, a bike builder named Mark Groneweld met Ray Molina at the Interbike convention in Las Vegas and test rode one of Molina’s bikes. Gronenweld and another bike builder named John Evingson collaborated and began building small production runs of bikes using Molina’s rims. These were the first production fat bikes.
In 2005, Surly introduced the Pugsly. This was the first fat bike that was widely available commercially in bike shops worldwide. It used Large Marge 65mm rims and Endomorph 3.8” tires. In the years that followed, numerous bike manufacturers began introducing fat bikes. Now, even the big manufacturers like Trek, Giant, Specialized, Salsa, Kona, and many more offer fat bike models in their product lineups.
For more in-depth info on the history of the fat bike, check out this excellent article from adventurecycling.org.
Fat Bike Pros
1. Fat bikes allow you to ride in deep snow, loose sand, and mud
This is possible because the wide tires distribute the weight of you, the bike, and your gear across more surface area. The fat tires put less pressure on the ground. This allows the tires to roll over the snow, sand, and mud instead of sinking in and getting caught up as a standard mountain bike tire would. This rollover feature is often called flotation.
Additionally, the extra-wide tires form a larger contact patch with the ground, which creates excellent traction on slippery snow, ice, and sand. The fat bike won’t try to slide out from under you when you hit a slick patch. To further increase traction on ice, you can install studded tires. You can ride a fat bike where no other bike can go. For this reason, fat bikes are a great choice for those who live in a sandy desert or snowy area.
2. Fat bikes offer a smooth and comfortable ride
The high volume fat tires can run at incredibly low air pressure. This makes the tires very soft. Soft tires absorb shocks and vibrations from the road or trail. When you hit a rock in the trail, the tire deforms around it and absorbs the impact instead of bouncing off. This improves comfort and reduces fatigue while riding rough terrain because you’re not bouncing around too much. The ride is much less harsh on a fat bike. Some fat bikes also have suspension to further improve the ride quality.
In addition, the frame geometry of most fat bikes offers a comfortable upright riding position. This puts very little stress on the back, neck, and shoulders.
3. Excellent traction/grip
The wider higher volume fat tires make a larger contact patch with the ground than more narrow mountain bike tires. This increases traction by creating more friction between the tire and the ground.
You can also run fat tires at the extremely low air pressure of 5-8 psi. This makes the tire soft so even more tread contacts the ground. This gives you even more traction.
The extra traction is particularly important when riding slippery surfaces like snow, ice, sand, and wet rocks. Increased traction also allows you to corner, accelerate, and most importantly brake harder without your tires slipping.
4. You can ride a fat bike year round in all weather conditions
If you live in a snowy climate, you probably store your bike for the winter after the first snow falls. A fat bike allows you to ride 12 months out of the year instead of 7-8. Fat bikes handle the snow and ice incredibly well. After all, it’s what they were designed for in the first place.
5. You can run narrow wheels to make the bike multi use
Most fat bike rims are narrow enough to mount 2-3” mountain bike tires. Alternatively, you could buy an extra set of wheels with narrower rims so you could mount 27+, 29er, or 29+ tires instead. This essentially turns your fat bike into a regular mountain bike. You could easily swap between your fat wheels and mountain bike wheels depending on the riding conditions.
This makes fat bikes incredibly versatile. For example, on a day when you plan to ride on the road, you could mount your more narrow tires and run them at a higher air pressure.
6. Fewer broken spokes and cracked rims
High volume fat tires act as shock absorbers. The rims and spokes take very little impact when you hit something a bump or drop from a ledge. The wide rims are also structurally stronger than mountain bike rims because they have much more material.
In addition, fat bikes usually have smaller diameter rims (usually 26” or 27.5”). These smaller diameter wheels use shorter spokes which are structurally stronger than longer spokes used on 29” wheels.
For these reasons, broken spokes and cracked or warped rims are much less common on fat bikes. You can also carry more weight without worrying about damaging the wheels. This comes in handy while bikepacking or bicycle touring.
7. Fat Biking is good exercise
The big tires take more energy to get rolling and maintain speed. Riding a fat bike requires more effort than mountain biking. You’ll burn up to 1000 calories per hour. This makes fat biking an excellent workout for weight loss or generally improving your physical fitness. Fat biking can greatly improve your strength and stamina.
Fat biking is also great cross-training for skiers and snowboarders. In fact, it is becoming so popular that some ski resorts are starting to offer fat bike rentals for those that want to try something different.
8. You can ride off-trail
With a fat bike, you aren’t limited to staying on the bike path. You can forge your own trail. Fat bikes ride over large rocks, sandy sections, loose gravel and dirt, and stream crossings with ease. You can ride places that you thought a bike could never go before.
Of course, just because you can ride somewhere doesn’t mean you should. Before riding off-trail, be sure to check the local regulations. You don’t want to damage the environment or tear up a hiking trail where bikes aren’t allowed.
9. You can run fat bike tires at incredibly low air pressures
The low air pressure gives fat bikes their incredible floating feeling. You can run your fat bike tire pressure as low as 5 psi when riding in soft conditions. This is possible because the high volume tires won’t bottom out and hit the rim as easily when running at low pressure. Also, you don’t have to worry about pinch flats because most fat bike tires are tubeless rather than tubed.
Running your tires at low pressure improves the ride quality because the tires absorb shocks and vibrations. It also improves traction by allowing the tires to simply deform around rocks, roots, bumps, potholes, etc. instead of bouncing off or getting hung up.
The ideal fat bike tire pressure depends on the surface you’re riding. For soft surfaces like sand and snow, 5-8 psi (.34-.55 bar) is ideal. For general trail riding, 8-12 psi (.55-.83 bar) works well. When riding in rocky conditions or on solid trails a fat biker may inflate their tire up to 12-15 psi (.83-1. bar). For riding on pavement, you can air the tires up to 20-25 psi (1.38-1.7 bar).
If the ride feels too bouncy, you can reduce the pressure by 1-2 psi. If you feel like your starting to slip around, let some air out. When you’re riding on a hard surface, you can increase the pressure a bit to increase efficiency.
10. Fat bikes inspire confidence and are great for beginners
Fat bikes are easy to ride because they are very forgiving. You can tackle technical terrain by simply lumbering over roots and rocks instead of steering around them. If you hit a bit obstacle, chances are, your wheel will bounce over it. The wide tires also offer excellent balance and stability.
Because fat bike tire have such great traction, you can easily tackle slippery surfaces like ice and sand without worrying about the bike sliding out from under you. The extra grip from the fat tires also allows you to stop, turn, and accelerate hard. You don’t have to worry as much about losing traction.
All of this inspires confidence. For these reasons, fat bikes are an excellent choice for anyone who is new to off-road cycling, including children.
11. Fat bikes are great for bicycle touring, bikepacking, and expedition rides
Fat bikes are becoming popular among bikepackers and bicycle tourists because they allow you to explore more off the beaten path places that a standard mountain bike can’t take you. They can handle rocky hiking trails, stream crossings, and sandy stretches with ease. You can haul plenty of gear on a fat bike with bikepacking bags, panniers, or a trailer.
Expedition riders also choose fat bikes for their off-trail capabilities. For example, fat bikes have been used to ride across the Sahara desert, and in Antarctica. My favorite bikepacking Youtuber, Bike Wanderer, also rides a fat bike.
Fat bikes are slow. They turn slow and the top speed is low. You can just kind of chug along like a tractor. This helps when riding technical sections because you have plenty of time to think about how you’re going to handle each obstacle in the trail. If you fall, the likelihood of getting injured is lower because you weren’t traveling very fast anyway. Also, with a fat bike, you’re more likely to ride off-road where there isn’t any dangerous traffic.
13. Fat bikes are cool, fun, and unique
The big knobby tires look rugged and gnarly. Being able to ride pretty much anywhere adds a new element to cycling. It’s a lot of fun riding on a sandy beach or snow covered trail. In addition, fat bikes are still a small niche in cycling. It’s cool to ride something a bit different than everyone else on the trail.
Fat Bike Cons
1. Replacement fat bike parts can be difficult to find
Fat bikes use non standard sized tires, rims, hubs, bottom brackets, and cranks. If any of these parts fail or need to be replaced while you’re out riding, you may have trouble finding a replacement. Many bike shops don’t stock fat bike parts.
This is particularly problematic if you’re bicycle touring or bikepacking in a developing country or a remote region. For example, if you crack a rim or destroy a tire while fat biking through the Andes, you might need travel to the nearest capital city or even fly to another country to buy the parts that you need. Even in the developing world, fat bike parts can be difficult to find. If you live in a small town or rural area, you may need to order your parts online.
2. Fat bikes are inefficient because the big tires create a lot of rolling resistance
The wide, low-pressure tires deform at the contact patch so more rubber contacts the ground. This creates a lot of friction, which slows you down and wastes energy. The wide tires also create more air resistance while traveling at speed. You have to spend more energy to overcome the resistance. In addition, fat bikes are heavier. It takes more energy to bring the extra mass up to speed.
Fat bike tires don’t maintain speed as well as harder, more narrow mountain bike tires so you have to pedal more. When you stop pedaling, you slow down faster. When riding a fat bike, you’ll burn more energy and cover less ground than you would on a mountain bike. For this reason, fat bikes aren’t ideal for long distance touring, unless you plan to spend the majority of your time riding off road.
3. Fat Bikes are Heavy
The extra-wide tires and rims have more material, which makes them weigh more. A standard mid-range fat bike weighs around 33-40 lbs. The lightest fat bikes with carbon fiber frames weight around 30 lbs. To compare, an average mountain bike weighs around 30 lbs with the lightest models weighing in at around 22 lbs. The extra weight reduces efficiency and makes the bike feel more cumbersome to ride.
4. Fat bikes are slow
The extra rolling resistance created by the wide, low-pressure tires slows you down considerably. Particularly when riding on road. You can’t accelerate as fast and you’ll maintain a lower average speed when riding a fat bike. You’ll spend more time in the saddle to cover the same amount of ground as you would on a mountain bike. This can be a problem if you’re riding with friends who ride faster bikes.
5. Fat bikes are less maneuverable
The bulky and heavy tires and wheels make the steering less responsive. This makes it harder to navigate technical terrain. The wide tires and frame make the bike feel a bit cumbersome. You can’t manhandle a fat bike like you can a lightweight mountain bike.
6. Frame options are more limited
Fat bikes are a small niche in cycling. Most big bike manufactures only offer one or two fat bike models. If you walk into an average bike shop, you might see a couple of fat bikes but dozens of mountain bikes. In a small bike shop, you might not see any fat bikes at all.
Having said this, fat biking is growing in popularity. At this point, all of the major bike manufacturers offer fat bikes including Trek, Surley, Giant, Kona, Salsa, Specialized, KHS, and more. There are plenty of fat bike options to choose from but you might not be able to get exactly what you want from your favorite manufacturer.
Generally, a fat bike costs more than a comparable mountain bike. The extra cost comes from the specialty components such as the tires, rims, and hubs.
Most of the extra cost comes from the tires. Quality fat bike tires are expensive. In some cases, they cost more than car tires.
The rims also add a considerable amount of cost. They need to be made from strong and lightweight materials so they aren’t too heavy. These kinds of materials are expensive. The extra material adds cost as well.
Mid range fat bikes cost about $1800-$2200. Of course, budget fat bike options are available. You can buy an entry level fat bike for less than $500.
8. Fat tire options are limited
Fat bikes are nowhere near as popular as 29er mountain bikes. Because demand is lower, manufactures offer fewer fat bike tire options.
When selecting fat bike tires, you’ll want to consider the type of terrain you plan to ride as well as the amount of weight you plan to carry. You can choose from different widths, tread patterns, and weights. Fat bike tires are available in tubed and tubeless options. If you plan to ride in the snow and ice, studded fat bike tires are also available.
9. Fat bikes can cause knee or hip pain for some riders
In order to maintain a straight chainline, fat bike pedals must sit further apart. This pedal position forces your feet and legs to sit further apart. Almost like you’re riding a horse. The distance between the points where the pedals attach to the crank arms is called the Q factor.
A wide Q factor puts your feet and legs in an unnatural position which can cause knee and hip pain. This pain is particularly common while riding at a high cadence with clipless pedals. Some people’s anatomies can deal with a higher Q factor than others. Riding in bulky snow boots moves your feet even further apart and can make matters worse.
A typical Q factor for a fat bike usually falls between 190mm and 230mm. For comparison, standard mountain bike Q factor usually falls between 155mm and 190mm.
A Q factor of 160mm-180mm is ideal for most riders. Some manufactures are finding ways to engineer fat bikes with lower Q factors in the 175mm-185mm range.
For more in depth info on Q factor, check out this great article from Cycling Weekly.
10. Harder to transport
The extra weight and size make the bike harder to transport. For example, maybe you have to lift the heavy bike onto a bike rack on your car. If you have to ship the bike or fly with your bike, you may have to pay more.
Another problem is that the wide tires also don’t fit in some bike racks. For example, many car top bike racks and bike racks on city buses wrap around the tire to hold the bike in place. Fat bike tires are often too wide to fit in these racks. Luckily, some cities are installing racks that can accommodate fat bikes.
11. Fat bikes typically have fewer gears
Most fat bikes have a wide range 1x drivetrain with one chainring and a 10, 11, or 12 speed cassette for a total of 10-12 gears. Some fat bikes are single speed. This is because the Q factor is already so wide with the extra wide bottom bracket that you wouldn’t want to make it any wider with 2 or 3 chainrings. If you need more gears, you could use an internal gear hub.
On a mountain bike, on the other hand, you can use a 2x or 3x drivetrain with 20-30+ gears if you prefer.
12. Fat bikes don’t teach you some technical skills
When riding a fat bike, you can pretty much ride over any obstacles in the trail including roots, rocks, dips, branches, sandy patches, etc. The tires deform to absorb big bumps and maintain traction in pretty much all situations.
This can make you lazy. It’s like mountain biking on easy mode. You don’t learn how to properly avoid or navigate obstacles in the trail when you can lumber right over them instead. If you switch from a fat bike to a mountain bike, you’ll have to remember your limitations.
13. You have to adjust the tire pressure often when fat biking
When riding a fat bike, tire pressure is critical. If your tires are too soft, you risk rim strikes which can cut your tire. Efficiency also suffers. If you run the pressure too high, the tires act like basketballs and bounce off every bump they hit. This reduces your ride quality. Traction also suffers when the tires are too hard.
To solve these problems, you have to adjust your tire pressure often to achieve the ideal mix between performance, comfort, and durability. When riding a fat bike, you should always carry a tire gauge and pump so you can always easily make adjustments when you change terrain. Having to adjust your tire pressure is a minor annoyance.
14. Fat bikes draw attention
While out riding your fat bike, you get some stares from non-cyclists. Occasionally, someone might stop to ask you to ask you about your strange bike with big tires. These people are usually friendly and curious. This could get annoying if you’re the kind of person who likes to blend in and not draw any attention to yourself. Juts something to consider. Of course, if you’re out riding your fat bike where it’s supposed to be ridden, out in the middle of nowhere off-trail, there is nobody to bother you.
Mountain Bike Pros
- Mountain bikes offer better parts availability- Mountain bikes are one of the most common types of bicycles around the world. Wherever you are, you can almost always find a spare tire or tube. In most of the world, finding a rim or even an entire wheel won’t be a problem. How easy spare parts are to find depends on the wheel size you go with and where in the world you ride. Generally, 26” wheel parts are more common in the developing world and 700c wheel parts are more common in the developed world. Fat bike parts aren’t all that common anywhere.
- More efficient- Mountain bike tires create less rolling resistance. The tires are more narrow and run at higher air pressure so the contact patch with the ground is smaller. This creates less friction. The more narrow tire also creates less air resistance while riding at speed. These factors make mountain bikes more efficient. It takes less energy to keep the bike at speed. When you stop pedaling, you keep coasting further. This allows you to travel further on a mountain bike using less energy.
- Cheaper- Mountain bikes are available at all price points. Decent mid-range models go for around $1000-$1800. You can buy a cheap entry-level one from a big box store like Walmart for just over $100. Used mountain bikes are incredibly common as well. If you keep an eye out on Craigslist or Facebook Marketplace, you can score a great mid-range mountain bike for $200-$300. Fat bikes, on the other hand, start at around $500 for a cheap model and around $2000 for a mid-range model.
- Faster- Because mountain bike tires have less rolling resistance and weigh less, you can maintain a higher average speed. You can also accelerate faster. Particularly while riding on pavement.
- Lighter- Mountain bike tires and rims are much more narrow and use less material to make. This makes them lighter. On average, a mountain bike weighs 5-10 pounds less than a comparable fat bike. A lighter bike is faster, more efficient, and more maneuverable.
- More options- Mountain bikes are one of the most popular types of bicycles. Most big bike manufacturers offer dozens of different options in terms of frame geometries, frame sizes, wheel sizes, suspension systems, etc. If you walk into an average bike shop, you’ll see dozens of different mountain bikes to choose from.
- More maneuverable- Lighter wheels steer faster, making the bike more responsive. Because mountain bikes are lighter, they are easier to manhandle. This increased maneuverability makes it a bit easier to navigate technical terrain in some situations.
- You can run road tires on a mountain bike to make your bike multi-use- Most mountain bike rims can accept road tires as narrow as 28mm. Narrow tires greatly improve efficiency and allow you to ride at a faster average speed while riding on road. If you plan to ride both on and off-road, you can buy a second set of wheels. If you install road tires on one and off-road tires on the other, you basically have two bikes in one. You can easily swap the wheels out in just a few minutes.
- Mountain bikes can have more gears- Mountain bikes are available with 2x and 3x drivetrains. This way, you can have 30 or more gears with a very high gear range. Fat bikes are limited to 1x drivetrains with 12 gears.
- Mountain bikes teach you more technical skills- When riding a mountain bike, you have to learn how to avoid obstacles. You need to learn how to balance, corner, and climb while riding through technical sections. You may want to learn how to drop, hop, lift a wheel, etc. With a mountain bike, you can’t just plow over every bump, root, or rock like you can with a fat bike. The more skills you have, the more types of terrain you can ride. These skills also come in handy if you plan to get into racing.
- More versatile- Mountain bikes can be used for pretty much any type of cycling including recreational riding, touring, off road riding, and commuting. This makes them a great choice for casual riders and those who can only afford one bike.
- Mountain bikes draw less attention- Mountain bikes are incredibly common. Nobody bats an eye when they see one. You can blend in on the trails, in the city, and on bike paths.
Mountain Bike Cons
- There are some types of terrain that you can’t ride with a mountain bike- Mountain bikes don’t handle sand, snow, or deep mud very well because the tires tend to sink in. When this happens, it becomes almost impossible to pedal. The bike may try to slip out from under you as well on slippery surfaces. You’ll have to walk the bike more often. Surfaces that are covered in large rocks can also be difficult to navigate with a mountain bike.
- The ride is more harsh- Mountain bike tires don’t absorb shocks and vibrations as well as fat bike tires because they are lower volume and run at higher air pressures, making them harder. When you hit a big bump or rock in the trail, the shock transfers into your body. Of course, many mountain bikes have suspension to smooth out the bumps. This helps greatly.
- Wheel damage is more common on mountain bikes- Because mountain bike wheels are larger in diameter (usually 29”) and more narrow than fat bike wheels, they are structurally weaker. They use longer spokes which bend or break more easily. The rims can also twist or crack under stress. Additionally, the harder, lower volume tires don’t absorb as much shock as the soft, high volume fat tires. The rims take more impact. For these reasons, cracked rims, warped rims, and broken spokes are more common. Mountain bikes also can’t handle quite as much weight. Of course, well-built wheels are incredibly strong and long-lasting.
- Mountain bikes offer less traction/grip- Mountain bikes are made for off-road riding. They get excellent grip but not quite as much grip as fat bikes. The reason is that the tire’s contact patch with the ground is smaller because the tires are more narrow. The tire creates less friction with the ground. You also can’t run the tires at as low of air pressures because they would bottom out and hit the rim, causing pinch flats, cut tires, or rim damage. Because the tires don’t get quite as much traction, they don’t handle slippery surfaces like snow, ice, sand, loose rocks, etc. as well. You can’t corner, accelerate, or brake as hard on loose or slippery surfaces.
- You can’t mountain bike year-round if you live in a snowy climate- You may have to store your mountain bike for a few months per year. One potential solution is to mount studded snow tires. These allow you to ride on hard-packed snow and icy streets without slipping around too much. They still sink into soft snow though.
- Mountain bikes take more skill to ride well- Anyone can ride a mountain bike but to ride one well through technical terrain takes a great deal of skill. It takes time to develop these skills.
Wheel and Tire Sizes Considerations
Fat bike wheels come in two diameters: 26” and 27.5”. The ideal size depends on a number of factors including, the terrain you plan to ride, your height, and tire width you plan to use.
Larger diameter wheels perform better on uneven terrain because they have better rollover characteristics. They don’t get hung up in holes and bumps. Keep in mind that larger diameter wheels make the bike sit almost 1” taller, assuming all else is equal. This is worth considering if you’re a shorter rider.
Most fat bike frames can fit a wider tire when you use smaller diameter wheels. This is because the fork arms and stays widen as they approach the hubs. If you want to use 5”+ wide tires, you may have to go with 26” wheels.
When it comes to fat tire width, you have a range of sizes to choose from all the way from 3.7” to 5”+. The ideal size depends on the weight you plan to carry. Wider tires can support a heavier load without sinking in because they distribute the weight of the rider, bike, and gear over a larger surface area.
If you’re a heavy rider or you plan to go bikepacking fully loaded with gear, you’ll want a larger tire in the 4”-5” range. Lighter riders can get away with lower-volume tires that measure less than 4” wide.
Mountain Bike Wheels and Tires
Mountain bikes come in 26”, 27.5” (650b), and 29” wheel diameters. Larger wheels offer better rollover characteristics and less rolling resistance. For more info, check out my wheel size guides:
Most mountain bike tires measure between 1.8” and 2.5” wide. Wider tires offer better float but create more rolling resistance.
Who Should Ride a Fat Bike?
Fat bikes are an excellent choice for anyone who spends most of their time riding off-road, bikepackers, those who ride in deep sand on the beach or in a desert environment, as well as those who ride in snowy environments. The wide tires float over soft surfaces without sinking in and offer loads of grip. A fat bike can take you places that no other bike can go.
Fat bikes are also a great choice for beginner cyclists because the fat bike ride quality inspires confidence. Fat bikes are incredibly stable and forgiving. They roll over obstacles easily and allow you to tackle technical terrain more easily than you could on a mountain bike. Fat bikes are also great for those who ride for exercise. You’ll burn a lot of calories while fat biking.
If you never plan to ride on sand or snow, there is really no reason to choose a fat bike over a mountain bike. Fat bikes also aren’t ideal for commuters or those who ride on road often. The reason is that fat tires are inefficient and unnecessary for road riding. Those who travel with their bike often may also want to avoid fat bikes. The extra weight and bulk makes them harder to transport.
Who Should Ride a Mountain Bike?
Mountain bikes are a great choice for commuters, bikepackers, those who spend time riding both on and off-road. Mountain bikes handle most types of terrain incredibly well. In addition, mountain bikes are efficient enough to ride long distance on road. Particularly if you mount tires that measure less than 2” wide. They are also a great choice for those who only have space to store or a budget to afford only one bike. Mountain bikes can do it all. They are also significantly cheaper than fat bikes.
A Note About Gear
Most fat biking takes place in cold, snowy climates. You need to properly prepare for riding in winter conditions. This means dressing warm. When fat biking in the winter, you should dress pretty much the same way as you would if you were going skiing or snowboarding. To stay comfortable, you need to keep your head, hands, and feet warm.
Layer your clothes. Wear two pairs of gloves. Wear booties over your cycling shoes, or better yet wear winter boots and use flat pedals instead of clipless. To keep your head warm, wear a hat or ski mask under your helmet. Wear a scarf or neck gaiter. Use goggles. If it’s particularly cold, consider using a ski helmet instead of your bicycle helmet.
This budget fat bike from Mongoose features 26” by 4” knobby tires, a 7 speed drivetrain, disc brakes, and a durable steel frame. This would be a great choice for someone who is just getting into fat biking and doesn’t want to spend thousands on a new bike.
This lightweight carbon-framed fat bike comes with 27.5 by 3.8” tires and a 12 speed SRAM GX Eagle groupset. The drivetrain is designed with a narrow Q factor for reduced knee and hip strain. The bike features 445mm chainstays and wide handlebars which inspire confidence and allow for excellent maneuverability. The Salsa Beargrease is available in an aluminum-framed version as well.
Fat bikes can handle terrain that no other bike can handle and take you places that no other bike can go. For example, with a fat bike you can tackle deep sand, snow, and mud with ease. Fat bikes also handle extremely uneven surfaces that are covered with rocks, dips, bumps, roots, potholes, etc. This is possible because the extra-wide fat bike tires distribute the weight of the bike and rider over more area. This allows the tires to float on top of soft surfaces without sinking in and getting hung up. This way, you can spend more time riding the bike and less time walking.
Of course, fat bikes aren’t the best choice for every rider. If you stick to the trails or spend a considerable amount of time riding on road, you may be better off with a mountain bike. A good mountain bike can handle most of the same terrain as a fat bike with greater efficiency and at a lower cost. In the end, this choice comes down to personal preference and the types of surfaces that you ride as well as your budget.
Where do you stand on the fat bike vs mountain bike debate? Share your tips and experience in the comments below!
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