Over the past decade, gravel bikes have become an increasingly popular alternative to mountain bikes. They are fast, efficient, and versatile. At the same time, they do have some limitations. In this guide, I’ll outline the differences between gravel bikes and mountain bikes. I’ll also list the pros and cons of riding a gravel bike vs mountain bike to help you determine which is best for you.
In this guide, we’ll cover gearing, frame geometry, suspension, tires, the ride position, handlebars, efficiency, and more. We’ll also compare gravel bikes to some different types of mountain bikes including including cross country mountain bikes, downhill mountain bikes, trail mountain bikes, and more.
I started riding a gravel bike about 5 years ago when I first got into bikepacking. I’ve also been riding mountain bikes for most of my life. In this guide, I’ll share my experience with these bikes.
Key Takeaways
Gravel bikes are a cross between a road bike and a mountain bike. They feature drop bars, a rigid frame, wide tires, wide-range gearing, an upright geometry, and disc brakes.
Gravel bikes are ideal for those who ride mixed terrain, long-distance riders, bikepackers, and road cyclists who want to ride off-road.
Mountain bikes Mountain bikes are designed for off-road riding. They feature a heavy-duty frame and wheels, suspension, flat handlebars, an upright geometry, wide knobby tires, and low gearing.
Mountain bikes are ideal for those who ride rough terrain and technical trails, those who value comfort, adrenaline junkies, downhill and enduro enthusiasts, and beginner cyclists.
What are the Differences Between a Gravel Bike and a Mountain Bike?
Gravel bikes and mountain bikes share a similar design with a few key differences.
One of the most significant differences is the handlebars. Gravel bikes have drop handlebars while mountain bikes have flat handlebars.
Suspension is another major difference. Gravel bikes usually have a rigid frame and fork. Mountain bikes have suspension. Some mountain bikes have dual suspension. Some have front suspension only.
Another key difference is the tires. Gravel tires typically measure 38-45mm wide. Most mountain bike tires measure 2.1-2.4” (53-61mm) wide. Mountain bike frames have wider clearance to accommodate the wider tires.
The geometry and seating position is also different. Gravel bikes usually have a more aggressive geometry with a forward leaning seating position while mountain bikes have a more relaxed geometry with an upright seating position.
The weight is also different. Mountain bikes usually weigh 3-5 pounds more than gravel bikes. They frame and wheels on mountain bikes are a bit more heavy-duty.
The gearing is another difference. Gravel bike gearing is higher than mountain bike gearing. Most gravel bikes use a 40-46t chainring with a 10-42t to 10-52t cassette. Gravel bikes tend to have more gears as well. Some models use 2X or 3X gearing or a road bike groupset. Some gravel bikes use a gravel-specific groupset. Mountain bikes usually use 1X gearing with a 30-36t chainring with a 10-50t or 10-52t cassette.
The surfaces that both bikes are meant to be ridden on are also different. Gravel bikes are designed to be ridden both on-road and off-road. They perform best on smooth unpaved surfaces such as hard-packed gravel roads, dirt roads, fire roads, and forestry roads. They can also handle some gentle singletrack trails.
Gravel bikes also perform well on pavement. A gravel bike can roll almost as fast as a road bike. This is possible thanks to the light and agile frame, road bike geometry, and drop bars.
Mountain bikes, on the other hand, are designed specifically to be ridden off-road. They can handle a much wider variety of terrain than gravel bikes thanks to their wider tires, suspension, stable geometry, and flat bars.
A number of different types of mountain bikes are available. The five most common include hardtail, trail, cross country (XC), enduro, and downhill mountain bikes. Different mountain bikes are suited for different types of terrain. They have different levels of suspension travel.
There are also several different types of gravel bikes available including adventure bikes, drop bar gravel bikes, and bikepacking bikes.
Gravel Bike Vs Mountain Bike
Suspension
Probably the biggest difference between gravel bikes and mountain bike is the suspension (or lack of suspension). Most gravel bikes don’t have any suspension. The frame and fork are completely rigid, just like a road bike. This design improves efficiency. A completely rigid gravel frame efficiently transmits power from the pedals to the rear wheel.
If you want suspension on your gravel bike, you can install an aftermarket suspension fork. A handful of companies offer gravel-specific suspension forks with low travel. Some examples include the FOX AX fork, Lauf Grit fork, MRP Baxter fork, and RockShox Rudy.
Some gravel bikes come with front suspension. These are becoming a bit more common. For example, the Specialized Diverge uses a Future Shock 2.0 headset. The BMC URS LT comes with a coil-sprung front shock.
When a gravel bike comes with suspension, it will be a minimalist suspension fork with much shorter travel than a typical mountain bike. Most gravel suspension forks offer 20-40mm of travel compared to 100+mm on mountain bikes. Some models only offer a few millimeters of suspension.
A suspension fork can help to smooth out bumps and vibrations while riding on rough gravel roads. The drawback is that suspension reduces efficiency. Every time the suspension compresses, energy is used. Sometimes the suspension compresses unnecessarily. This wastes energy that could have been used to drive you forward. To improve efficiency, gravel suspension tends to be pretty firm. The suspension only activates during a hard hit.
It is also common for gravel bikes to come with a suspension seatpost. These offer a built in shock absorber that dampens road vibrations and reduces shocks from bigger impacts. This greatly improves comfort while riding rough surfaces.
All modern mountain bikes have suspension. There are two different categories of mountain bike: hardtail and full suspension.
Hardtail mountain bikes only have front suspension. Most hardtail mountain bikes offer 120-140mm of suspension travel.
Full suspension mountain bikes have both front and rear suspension. They can have anywhere from 140-200+mm of suspension travel depending on the terrain that the bike is designed to handle.
Hardtail mountain bikes work well for casual mountain biking. These bikes are affordable, lightweight, and easy to maintain. They can handle a wide range of terrain including mountain trails, fire roads, and singletrack as well as some jumps and drops. If you need a bike with a little bit more off-road capability than a gravel bike but still want to have the ability to ride somewhat efficiently on pavement, a hardtail mountain bike is a good alternative.
Full suspension mountain bikes are much heavier and more expensive than hardtail mountain bikes. They are also more complex to maintain. Full suspension greatly improves traction, handling, and comfort while riding on rough terrain. The rear suspension holds the tires on the ground while you ride. The suspension allows the tires to roll over obstacles while maintaining contact with the ground. The tires don’t bounce around. This improves traction, allowing you to better control the bike while riding on extremely rough terrain. The suspension also absorbs bumps before they can travel into your body.
Full suspension mountain bikes are suitable for all types of mountain biking including downhill, trail riding, enduro, and CX. They work best for riding difficult trails with lots of rocks, roots, and drops.
These bikes are not efficient to ride on smooth roads and trails. The suspension tends to and rebound as you pedal. Every time you compress the suspension unnecessarily, you’re wasting energy. For this reason, full suspension mountain bikes are not designed for long-distance riding.
There are two different types of bike suspension systems available. These are air suspension and coil suspension. Air suspension uses compressed air to provide resistance. Coil suspension uses a wound steel or titanium spring to provide resistance. Both systems have their own set of benefits and drawbacks. For more in-depth info on both systems, check out my guides: Air Vs Coil Forks and Air Vs Coil Rear Shocks.
Handlebars
One of the most noticeable differences between gravel bikes and mountain bikes is the handlebars they use. Gravel bikes use drop bars while mountain bikes use flat bars or riser bars. The handlebars play a major role in your ride position and comfort as well as the handling and efficiency of the bike.
The drop bars used on gravel bikes are slightly different from the drop bars used on road bikes. They have the same general shape. The ends curve down and back toward you. The difference is that gravel drop bars are flared out at the ends. This makes the bars wider than standard drop bars. Most gravel drop bars measure 460-520mm wide. To compare, road drops measure 400-440mm wide. Gravel drop bars also tend to have a shallower drop than road drop bars.
Mountain bikes use much wider flat bars. These are simply long flat tubes. Most flat handlebars measure 580-600mm wide. Riser bars are also common on mountain bikes. Riser bars are flat bars that curve up from the clamp and raise the bars a couple of inches. They are wider than flat bars. They measure 685-700mm+ wide.
Gravel bikes are usually ridden at higher speeds and over longer distances than mountain bikes. Drop bars make sense for this type of riding. There are a couple of reasons for this.
First, drop bars offer three distinct hand positions. You can grip the bars on the hoods, on the tops of the bars, or on the drops. Having multiple hand positions allows you to adjust your hands and vary your grip. This improves comfort and reduces fatigue, allowing you to ride longer and further without your hands tiring out and going numb.
Drop bars also increase your efficiency while riding at high speeds by improving aerodynamics. You can crouch down in the drops and reduce the surface area that is facing into the wind. This reduces drag. The improved aerodynamics allows you to ride further while burning less energy.
Gravel riders tend to spend the majority of the time gripping the bars on the hoods. This position allows you to easily access the brakes and shifters. The drops offer an aerodynamic ride position that is great for sprinting, descending hills, and riding into headwinds. While gripping the flared drops, you have good leverage for steering and easy access to the brake levers. Gripping the tops of the bars puts you in a comfortable upright ride position.
There are some drawbacks to drop bars. Sometimes you have to move your hands to brake or shift. Drop bars also don’t offer quite as much leverage as flat bars. This makes steering in tight areas at slow speeds difficult. Drop bar components are also a bit more expensive than falt bar components. There also isn’t as much space for mounting accessories. You also have to re-tape the bars periodically.
Mountain bikes are usually ridden on more rugged terrain than gravel bikes. They are also ridden shorter distances and at lower speeds. For this type of riding, flat bars are ideal.
Flat bars are much wider than drop bars. Wider bars give you more leverage and allow you to steer more quickly and precisely. This is important while riding technical terrain. You need to be able to turn the handlebars easily to navigate obstacles and keep the bike balanced while riding at low speeds. Wide handlebars are also helpful while landing from jumps and drops because it’s easier to hold the wheel in place. The grip position also places you in an upright ride position with your hands placed far apart. This is comfortable. It’s also easy to grab the brakes quickly with flat bars. This improves braking performance.
The main drawback to flat bars is that they only offer one grip position. During a long day of riding, your hands can get tired because you’re always gripping in the same spot. The ride position also offers poor aerodynamics. Mountain bikes are less efficient while riding at high speeds for this reason. It is possible to grip the center of the drops and crouch down briefly to reduce drag but this position is difficult to maintain.
There are exceptions when it comes to handlebar type. Flat bar gravel bikes and drop bar mountain bikes exist but they are a bit less common. It is also possible to swap out the handlebars to a different style if you don’t like a particular type of handlebar.
For more in-depth info on handlebars, check out my guides:
Wheel Size
Most gravel bikes come with 700c wheels, just like road bikes. 650B wheels are also becoming common these days. 650B wheels are 38mm or about 1.5” smaller in diameter than 700c wheels.
Most mountain bikes come with 29” wheels (also called 29er). This wheel size has the same diameter as 700c wheels. They are both ISO size 622mm. 27.5” wheels are also becoming common. These are the same diameter as 650B wheels. They are both ISO size 584mm. For whatever reason, mountain bike wheels and tires are usually measured in inches while gravel tires are usually measured in millimeters.
In the past, 26” wheels were standard on mountain bikes. These days, 26” wheels are pretty much obsolete. They have been replaced by large 27.7 or 29 inch wheels.
Generally, smaller diameter wheels are preferable for smaller frames and larger diameter wheels are better for larger frames. If you run 700c wheels on a small frame, your toe can rub the tire when you turn. This is called toe overlap. Large wheels on a small frame can also throw off the geometry.
One major benefit of using smaller wheels is that you can fit wider tires. This can increase traction. Smaller wheels offer more tire clearance because the stays and fork arms widen as they approach the hubs. For example, a 650B gravel bike may be able to accommodate 50mm tires. The same frame with 700c wheels may only be able to handle 40mm tires.
For more info on tire size, check out my guide: 700c Vs 650B wheels.
Tires
Gravel bikes and mountain bikes use different types of tires. The tires play a major role in how the bike rides and how it handles different types of terrain.
When choosing tires, you’ll want to consider the width and tread pattern. There are some compromises you’ll need to make.
Gravel-specific tires perform better on smoother and faster terrain. This is because the tires are narrower and have lighter tread than mountain bike tires.
The most common gravel bike tire widths include 35mm, 40mm, 42mm, and 45mm. Most gravel-specific tires have a light file or diamond tread design. This works well for dry trails and pavement.
Gravel tires are also designed to be run at higher pressures than mountain bike tires. They are usually run at 20-50 psi, depending on the terrain.
Mountain bike tires perform better while riding at low speeds on rough terrain or slippery terrain such as rocks, roots, ruts, mud, sand, etc. This is because the tires are wider, more voluminous, and have a more aggressive tread pattern.
Some common mountain bike tires widths include 2”, 2.25”, and 2.4”. Mountain bike tires usually feature deep knobby tread with side lugs for extra traction on slippery and loose surfaces. Some mountain bike riders install different tire sizes on the front and rear. They may choose a wide and grippy front tire to maximize grip and a slightly narrower rear tire for some extra speed.
Mountain bike tires are usually run at lower pressures. 15-20 psi is common, depending on the terrain.
Narrow gravel tires with minimal tread and higher pressure have less rolling resistance. This allows you to ride faster and more efficiently on flat and smooth terrain. Gravel tires also offer enough traction to handle dry loose surfaces such as gravel and dirt. If you want to ride in muddy or winter conditions with your gravel bike, you may consider installing wider tires with a more aggressive tread pattern for extra traction. You could even install mountain bike tires, as long as your frame has enough clearance. For riding on snow and ice, consider installing studded tires.
Wider mountain bike tires have a larger contact patch with the ground. The lower air pressure allows the tire to deform at the contact patch so even more of the tire touches the ground. This improves traction because the tires create more friction with the ground. The knobby tread also improves grip. The wider, lower pressure tires can also deform around obstacles and absorb some bumps and vibrations. This improves comfort. You can ride over more rugged terrain with a mountain bike.
These days, most gravel and mountain bikers run tubeless tires. The main reason is that flat tires are much less common. Tubeless tires are filled with a sealant that automatically patches small punctures. If you run over a thorn and puncture a tire, you can just keep on riding. You won’t even notice it. You can also run your tires at lower pressure while riding tubeless because pinch flats are not possible. This increases traction. If you ride in an area where flats are common, such as the desert, tubeless tires are a great choice for either type of bike. Generally, mountain bikers benefit more from going tubeless. The main drawback of tubeless tires is that they are slightly harder to set up and maintain than tubes.
Some riders still prefer tubed tires because they’re simple to setup. They’re also easy to repair on the side of the road. These days, most bikes come with tubes installed but are tubeless ready. For more info, check out my guide to tube vs tubeless tires.
Most mountain bike tires and gravel tires also have some puncture protection built-in. This could be a sealant that fills punctures or a strip of hard material built into the tire that resists punctures.
Tire Clearance
Gravel bike frames are designed to fit much wider tires than road bikes or cyclocross bikes. Most gravel bikes can accommodate tires that measure 38-45mm wide. Some more off-road-oriented gravel bikes can accommodate tires up to 50mm (around 2”) wide.
Tire clearance seems to be trending up on newer gravel frames. This wide tire clearance allows you to mount a variety of tires to your gravel bike including road slicks, knobby mountain bike tires, and everything in between.
Mountain bikes have even more tire clearance than gravel bikes. Most cross-country mountain bikes are designed to accommodate tires that measure 2.1-2.4” (53-61mm) wide. Downhill mountain bikes usually have 2.5” tires. For comparison, 50mm gravel tires are about 1.97” wide. Some mountain bikes are designed to accommodate plus sized tires that measure 2.8-3” wide. Fat bikes have enough clearance for 3.7-5” wide tires.
When choosing tires for your bike, it’s important to consider frame clearance. Ideally, the tire should have at least 3mm of clearance between the tire and the closest part of the frame.
It’s important to note that advertised tire sizes are not really accurate. A 50mm tire from one brand could be a couple of millimeters larger than a 50mm tire from another brand.
If your tires are too wide for your frame, they can rub. You can also have trouble with debris getting stuck between the tires and frame if there isn’t enough clearance.
Before buying tires, it’s a good idea to measure your frame clearance.
Gearing
Mountain bikes and gravel bikes use very similar gearing. In the early days, gravel bikes used more road components in the drivetrain. In fact, they just used standard road groupsets.
These days, most gravel bikes use more mountain bike specific drivetrain components including 1X drivetrains and wide-range cassettes. The components are very similar but the gear ratios are different. There are also gravel-specific drivetrains available.
Generally, gravel bikes have slightly higher (harder) gearing than mountain bikes and lower gearing than road bikes. This higher gearing allows you to ride at higher speeds on flat and smooth terrain. The gearing also needs to be low enough for you to pedal up loose gravel grades without your wheel spinning out.
Mountain bikes tend to have slightly lower (easier) gearing. This allows you to power up steep hills and pedal through technical sections of trail. Mountain bikes don’t need as high of top speed.
For an example of common gearing, a gravel bike may use a 42t chainring and a 10t-44t cassette. To compare, a mountain bike may use a 32t chainring and a 10t-50t cassette. The larger chainring on the gravel bike makes the gearing higher.
In this example, the highest gear on the gravel bike is 42t-10t. This gives you a gear ratio of 4.2. The highest gear of the mountain bike is 32t-10t. This gives you a gear ratio of 3.2t. The gear ratio represents the number of times that the rear wheel turns for each revolution of the cranks. The gravel bike has a much higher top gear in this example. This higher gear allows you to cruise at higher speeds and reach a higher top speed with a gravel bike than you could on a mountain bike. You won’t run out of gears or ‘spin out’ while riding at speeds above 25mph.
The lowest gear on the gravel bike is 42t-44t. The gear ratio is 0.95. The lowest gear on the mountain bike is 32t-50t. The gear ratio is 0.64. This means that for every revolution of the cranks, the rear wheel makes 95% or 64% of a revolution respectively. In this case, the mountain bike has a lower low gear. This low gear will allow you to pedal a mountain bike up steeper hills than you could handle on a gravel bike. The gravel bike gearing is still low enough for climbing steep grades.
These days, all of the major bicycle groupset manufacturers offer gravel-specific drivetrains. Shimano’s gravel range is called GRX. Sram’s gravel range is called XPLR. Campagnolo’s gravel range is the Ekar. They offer the first 13 speed gravel groupset.
Shimano and Sram also offer an entire range of mountain bike specific gearing options. There are far more options in the mountain range. For example, Shimano offers the Deore, XT, and XTR ranges. Sram offers the XX1 Eagle, X01 Eagle, GX Eagle, and more. Both brands offer entry level options as well. You can also choose from mechanical and electronic gravel and mountain groupsets.
The most important decision you’ll have to make when choosing a mountain bike or gravel bike is whether you want to go with 1x or 2x gearing. 1X gearing means there is a single chainring. 2X gearing means there are two chainrings.
Most modern mountain bikes come with 1X gearing. Gravel bikes have either 1X or 2X gearing. There are benefits and drawbacks to both setups.
1X gearing eliminates the front derailleur and shifter. This simplifies your shifting. You only have one shifter to think about. You just shift up or down. There are also fewer parts to maintain. Less can go wrong. Modern 1X drivetrains offer almost as much gear range as 2X drivetrains.
There are several drawbacks to 1X gearing. The steps between gears are larger because there are fewer gears. Most 1X drivetrains have 11 or 12 speeds. 2X drivetrains have 20-24 speeds.
The chain also runs at a greater angle while you’re using the lowest and highest gears with a 1X groupset. This reduces efficiency because the chain creates more friction while running at an extreme angle. Most models use a chainring with alternating wide and narrow teeth and a clutched derailleur to keep the chain in place.
2X gearing also gives you more gears and a wider gear range. There are also smaller steps between gears.
Most 2X groupsets these days use super-compact chainsets. These offer extra low gearing. For example, Shimano uses 48/31t or 46/30t chainrings and an 11-32t or 11-34t cassette. This 2X setup gives you low gearing. This works well if you plan to ride your gravel bike on steep terrain or if you plan to carry heavy bikepacking bags or panniers.
Both gravel bikes and mountain bikes both have wide gear ranges. The gear range is the difference between the largest and smallest gear. A wide gear range means there is a large difference between the lowest and highest gear.
A modern wide range 1×12 speed groupset can give you over 500% of gear range. This is possible thanks to the extra large ‘dinner plate’ cassette cog that is common on most 12 speed cassettes. This wide gearing allows you to ride on a wide r