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Mountain Bike Vs. Fat Bike (Explained for Beginners)

Fat bikes are bicycles with wide tires, sometimes twice the width of the tires on a typical mountain bike. The wide tires usually are underinflated, making them ideal for riding over soft surfaces like snow, sand, and mud. With recent advances in technology, these bikes can be taken onto more technical terrain.

Core differences between a typical mountain bike and a fat bike are tire width and handling. Mountain bikes require specialized equipment to make the most of varied off-road terrain.  Fat bikes rely on tire width and low wheel pressure to roll over snow, sand, and other soft terrains.

Although fat bikes are often classified as mountain bikes, they occupy a unique space in the market. Previously, fat bikes were popular only on snow and sandy terrain; now, we see them in other areas of mountain biking territory.  While parallels can be drawn between the bikes, each nevertheless fulfills a different purpose for the rider. 

What Is A Mountain Bike

MTB Vs. Fat Bike

Mountain bikes are manufactured to be more durable than other types of bikes. Stresses from variable terrain can take their toll on components and frames alike. 

Strong wheels, knobby tires, adjustable suspension, sturdy frames, powerful brakes, and a straight handlebar are some elements that facilitate durability.

A mountain bike can be classified according to suspension type: 

  1. Rigid (no suspension)
  2. Hardtail (suspension fork)
  3. Full suspension (suspension fork and rear suspension)

Certain mountain bike types are more suited to rougher terrain than others, but similarities revolve around providing traction, shock absorption, and comfort while riding. 

The most popular mountain bike types can be broadly classified as terrain-specific. 

  1. Cross country:  nimble bike favoring fast-paced riding and uphill tracks.
  2. Trail:  equally capable on uphill and technical downhills.
  3. Enduro:  favors downhill riding, with enough gears to get you back up the next hill
  4. Downhill:  only for racing downhill at incredible speeds.  Near impossible to ride back up a hill. They are usually transported by lift or vehicle.

Mountain bikes can be used recreationally for touring and commuting efficiently. 

What Is A Fat Bike?

Fat bikes combine the look and frame of a mountain bike with fat tires up to 5″ in width. 

Even if the frame is similar to a mountain bike, there are significant differences:

  • Rigid frame, mostly without suspension
  • The complete bike is heavy compared to other mountain bikes.
  • Gear ratios are for powering the bike along; speed depends on how strong the rider is
  • Fat tires act as a suspension system.  

Tire pressure is filled at much lower psi than other bike tires, which results in fantastic traction. They are stable and are not made for high speeds.  Beginners and experienced riders alike feel confident and safe on this machine.  It’s just plain fun – anywhere, anytime.

Fat biking is increasingly popular. They are also seen with expedition riders, bike packing, and touring adventures. Cruiser and electric bike versions are becoming popular.  Most manufacturers and many bike shops offer a version for sale. 

As technology advances, these bikes become increasingly lighter in weight and more customizable to personalized riding preferences.

Interest In Fat Biking

The number of fat bike sales is not near that of typical mountain bikes.  Fat bikes came into the mainstream in the mid-2010s.  Some brands exclusively dealt in fat bikes; others added them to existing ranges.  The unique look of this bike with the ‘fat tires’ likely spurred on early sales. 

Riders who purchased fat bikes because they suited their type of riding kept upgrading them with newer models.  Advances in frame building technology saw riders progressing from steel to aluminum to carbon frame model.  Although fat bikes are here to stay, the popularity seems to have flattened out for a while. 

E-bike technology has now elevated fat bikes to new levels of popularity – offering even more people the ability to ride.  From the sunny beaches and hot, harsh wildlife areas in Africa to cold, wet, and snowy regions of the far Northern Hemisphere, fat bikes appear in one form or another.  

Fat bikes are developing into a broader category of their own.  Cruiser-style fat bikes and even dual-suspension fat bikes are hitting the marketplace.  

Ride Comfort, Performance, And Tire Choice

The advantage of a fat bike is in its name. It has ‘Fat’ tires, which means it has a thick wide wheel. The wide wheel, pumped at low pressure, increases riding comfort levels in all conditions and provides traction, especially when riding on snow or ice. A fat bike often has low gears to power through snow or sand easily.

Diffrences betwen mountain bikes and fat bikes

A comprehensive, but not definitive list comparing the two bikes really brings the differences home. 

Nr. Mountain bike Fat bike
1Range of differently priced bikes.Significant investment as a beginner bike, you pay for the versatility
2Bikes can be very light.Heavyweight bikes, although technological advances are shaving off some weight.
3Harder tires (more pressure) are easier to maneuver over most terrain, also roads.Softer tires make them challenging to ride, particularly on the road.
4Gearing is optimized for the type of riding (more gears)Intense workout, even over short distances
5Suitable for difficult terrain as it’s nimble and quick to respond, not as comfortableLots of cushioning, traction, and comfort. Good for difficult terrain
6Multi-functional – can cope with a wide variety of terrain.Multi-function bike – can cope with most terrain.
7Can’t handle all-terrain, esp heavy mud, sand, and snow.Fantastic traction: Handle on and off-road trips and terrain that’s soft sand, snow, and ice, as well as deep mud
8Not suited to ride deep sand and mudRide terrain not usually able to on a mountain bike
9Can’t ride in snowy areas in winter as they sink into the soft snowRide in diverse weather conditions
10Harsher ride as the tires are not run soft. Front and rear suspensions systems do mitigate.Smooth and comfortable ride
11Less traction and grip as the tire is narrower and pumped harder.Excellent traction /grip
12Wheel damage is common as they are larger, narrower, and structurally weaker than fat bike rims.Fewer broken spokes and cracked rims as the tire absorbs impact
13Replacement parts are easier to find.Replacement parts can be difficult to find because they aren’t so popular.
14More efficient ride: The narrower tires with higher pressure decrease rolling resistanceInefficient to ride due to the high rolling resistance
15Lighter and fasterHeavy and slower
16More maneuverableLess maneuverable
17Many frame options because they are of the most popular types of bikesFrame options limited
18Can swap tires out and put road-ready wheels on.Tire options limited
19Discomfort can usually be corrected by a good bike fitCan cause knee and hip pain due to wide Q-Factor
20Builds technical skills as it doesn’t just plow over obstacles.Doesn’t teach technical skills as it rolls over most obstacles with incredible ease
21Tire pressure is just checked before a ride.Best to adjust tire pressure over the varied terrain in a ride to increase riding efficiency
mtbfunplanet.com

Average Rim and Tires for mountain and fat bikes. 

Many variables play into rim and tire choice, not least the design of your bike, but also each rider’s tolerances and experience.

Mountain bike wheel choices can be overwhelming in many ways.  Here, we take the tire choice back to basics for the main mountain biking categories:

  • Cross country:  lightweight and fast-rolling tire for speed
  • Trail: all-round tire with moderate traction, durability, and speed
  • Enduro: good grip on the downhills and can take an impact
  • Downhill:  aggressive tires that can handle lots of impact, provide traction on fast landings and stick on turns. 

Mountain Bike Rim And Tire Size Chart

Tire choice and psi for mountain biking is a personal matter for each rider. The bike geometry can also prescribe maximum wheel rim width.

Mountain Bike Rim And Tire Size Chart
Tire internal rim width: 26 to 32” Tires widths 1.9” to 2.6” 25 to 35psi depending on terrain
Plus width:  35 to 45” Tire widths: 2.5 to 3” 25 to 35psi depending on terrain
mtbfunplanet.com

Too low pressure can increase the number of flats and decrease performance, whereas too high pressure can reduce the comfort level of the ride. 

Fat Bike Rim And Tire Size Chart

Keep in mind that fat bike tire weight can influence your decision.  Even a seemingly small difference in width can make a significant difference in overall bike weight

Fat Bike Rim And Tire Size Chart
Wheelrim width:
65mm Year-round riding
Tire width up to 3.8 to 4″:
– Light, corner easily and good in some snow conditions
– Good float
Wheelrim width:
80mm Can take a variety of tire sizes and profiles
Tire width 4 to 4.8.”:
– Suitable for all-purpose riding all year round.
– Does favor sandy/snowy conditions with little impact on cornering on off-road tracks
Wheelrim width:
90mm/100mm Go anywhere
Tire width: 4.3” to 5,2”:
– It takes you places you couldn’t dream of riding otherwise.
– Give the most float in deep sand and snow
– Flatten out to give most traction
– Strenuous/challenging to ride on hard surfaces
Tire Pressure – 5 to 8 psi – soft snow or sand
– 10 to 15 psi – general trail riding
– 20 to 25psi – hard pavement or tarmac.
mtbfunplanet.com

This table should be seen as a general guide and may vary between manufacturers. 

No absolute tire pressure can be prescribed. It usually depends on terrain, the type of riding, rider weight, and many other variables. Experiment with pressure, staying between the pressures recommended by the manufacturer. 

The more traditional rigid frame fat bikes used for softer riding conditions hardly need any suspension as it is “integrated” into the tires. Fat tires are good shock absorbers at lower pressure values due to the elasticity of the rubber, increasing ride comfort.

Best Terrain for Mountain Bike VS. Fat Bike

Where do a mountain bike and a fat bike take you to?  What type of ride are they made for?

Mountain bikes are versatile and conquer just about any terrain, from flat, fast sections to technical rough hilly terrain.  Suspension systems make the ride as smooth and comfortable as possible.

Fat bikes provide grip and unrivaled traction because the tire’s width is spreading bike and rider weight across a greater area. The increased contact area makes it possible to get through otherwise troublesome snow, mud, soft sand, and the likes. 

Fat tires are less likely to slip on wet ground, cut into deep sand, or crack when in contact with icy corners.  The tire acts as a suspension system

It comes into its own on snow paths and sandy beaches; typical mountain bikes cannot ride. For trails where fast reaction times and nimble steering and movement are required, a mountain bike will be more successful.   

Ride in any weather

For riders who are of the viewpoint that lousy weather doesn’t exist, only inappropriate gear, the good news is that fat bikes adjust to just about any weather conditions.

Due to the extra grip the wide tires provide, no surface will be a match for the wheels. They will grip wet stone or tarmac. Neither will they cut and dig in mud or snow.  Most fat bike tires come in a tread designed for off-road terrain, but some are available in an extra knobby pattern suitable for snow.

And, if you really need a reason to ride in truly windy conditions, here is the last thought:  Since fat bikes weigh more than a regular mountain bike, fat bikes are safer to ride in strong winds than their lighter counterparts.

A Comfortable Ride – Saddle Choice

Riding any bike is usually not the most comfortable activity as the seat and handlebar are the only points supporting most of the rider’s weight.  Comfort depends on saddle type, position on the bike, and suspension system.

Fat bike saddles are loosely modeled on the mountain bike saddle, which has some padding. Mountain bike saddles are constantly evolving to keep up with the latest frame geometry.

As mountain bike frame designs keep stretching the distance between the bottom bracket and bars for increased stability, the steeper the seat post angles become.  That means saddle length becomes shorter and in some cases, the back cut out in the saddle is no longer necessary.

The choice of fat bike saddles comes down to the type of riding primarily engaged in.  If you constantly push the pace and look for a hard workout, a performance saddle could be the more comfortable version. 

If it’s more about having the most comfortable ride, a cushioned saddle is the way to go. It doesn’t mean that you can’t push the pace with this kind of saddle.  Constant chafing of the saddle is an indication to consider a move to a more performance-based model.

Differences between performance and recreational saddles – An overview

Performance Fat Bike Saddle Recreational Fat Bike Saddle
Ride a faster with slimmer shape saddleWider shaped saddle for slower riding speeds
Standing up often to power the bike, a slimmer shape saddle is usually preferred.Mostly seated and padding on seat area is more comfortable
Chaffing is minimized by saddle shapeOverall comfort is maximized
Firm foam cushioning with shorter (saddle) nose to easily transition from seated to standing positions– Gel – the softest for casual/occasional riders
– Foam cushioning – a good all-round performance/comfort option for recreational riders
mtbfunplanet.com

Bike maintenance

Mountain bikes are complicated machines with many moving parts which require maintenance regularly.  Routinely cleaning the bike and exposed parts after every ride will increase longevity.

Having the suspension systems serviced at correct intervals is essential if your riding performance should remain the same. 

Cleaning off dirt and grime from wet and snowy rides after every ride is a must to minimize corrosion from sand, salt and snow deposits.

Considering fat bikes are mostly of rigid frame build, there are not as many moving parts that require routine servicing or get damaged and need to be replaced regularly. 

Riding Gear

Mountain biking gear needed is relatively terrain-specific. Cross country riders will have a good helmet and gloves, while downhill riders will wear full-face helmets, goggles, and protective elbow and knee guards. Appropriate weather-related gear like rain jackets or windjammers are readily available

Fat bike riders spend a lot of time outdoors in winter.  The gear required in snow-bound areas is the same as for snowboarding or skiing.

Keep the head, hands, and feet warm. Layer clothes, wear two layers of gloves, fit booties overshoes or ride in winter MTB shoes and flat pedals. Wear a ski mask under your helmet or wear a ski helmet in exceedingly cold conditions.

Conclusion

Mountain biking is a sport that requires specialized equipment to handle the demands of off-road trails. It’s about exploring, experiencing nature, and testing your limits both mentally and physically.

Fat bikes were initially developed to be sand and snow bikes. The main difference between fat bikes and regular mountain bikes is that fat tires are wider than standard tires, making them more suitable for riding on soft surfaces like sand, mud, or snow and hard ice-covered areas.

The unusual proportions of fat bikes draw attention. But actually riding such a bike is the only way to understand why anyone who has ridden one enjoyed it.

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I started mountain biking many years ago to improve my overall health state. After my first ride, I fell in love with the sport. Now I spend dozens of hours a week researching and training to compete in local XC and Enduro events.