mountain bikes

Mountain bikes are super versatile. They can be used to haul groceries home, cruise the bike path or tour the planet. But their primary use is to capably get their riders along dirt trails—mountains are optional.

What's the best mountain bike for you? The key points:

  • Know your riding style (we help you with this below). Your riding style helps you quickly narrow the bike selection to relevant models. Not sure? Go for a general “trail bike.”
  • Know your budget. Basic models start around $500 but lighter, faster models with full suspension and higher-end components can easily exceed $3,000.
  • Test ride several bikes, if possible, in the category you want. It’s highly likely that one will stand out as being a better ride for you.

Note: This article covers the basics of mountain bikes. For a more detailed discussion, talk with the bike pros at your local REI store.

Shop REI's selection of mountain bikes.

Know Your Riding Style

To be a savvy bike shopper, first gauge your riding intentions and experience.

Mental check in: What is inspiring you to get a mountain bike? Are you an experienced road cyclist looking for a little variety? Will you be doing family outings on bike paths and maybe towing a bike trailer with a child? Or are you out to build your fitness level and skills on local trails?

Suggestion: For errands, family outings or occasional use, a basic model will serve you well. If you desire to go farther, faster, higher or harder, then higher-quality components will be well worth the extra spend.

Physical check in: Are you fit, flexible and looking to learn new skills? Or are you occasionally active and simply looking to explore a variety of trails? Or are you some combination of the above?

Suggestion: If you are active and in good condition, you’ll enjoy either a hardtail or a full-suspension bike. If you suffer any joint or back ailments or simply want a smoother ride, a full-suspension bike will probably be more to your liking.

Types of trails: How wide or narrow, flat or steep, smooth or bumpy are the trails you plan to ride? The type of trail can have an influence on the most appropriate bike for you. Ask experienced riders what sort of mountain bike is suitable for the trails in your area.

Suggestion: For relatively smooth trails or a mix of dirt and pavement, a hardtail will serve you well. For trails that are rough, rocky, rooty or have small drops, consider a full-suspension bike or a hardtail 29er.

Types of Mountain Bikes

Mountain bikes are described and advertised by a variety of terms. Knowing the language can help make a more informed choice. Leading brands include Cannondale, Diamondback, GT, Marin, Novara, Raleigh and Scott.

Some common categories:

Trail: General-purpose mountain bikes for everything from dirt roads to singletrack trails. Most mountain bikers are “trail riders” and most mountain bikes at REI are trail bikes (either hardtail or full suspension).

All mountain: Like trail bikes, but with stronger frames and longer suspension travel. They’re best for riding more technical trails with steeper descents, increased obstacles and small jumps. Most are full-suspension bikes.

You may also hear of specialty mountain bikes not typically offered by REI:

Cross country: Light, nimble bikes best for competitive events featuring steep ascents and tight turns. They are not suited for the high impact of jumps and landings. Emphasis is on speed, ascending and cornering.

Freeride and downhill: Designed for going fast downhill and soaking up the rocks, roots, bumps and jumps along the way. Often shuttled to the top of mountains by vehicle or a ski-resort chairlift, they are not as fun or as efficient to ride uphill.

Dirt jump: Bikes for those who like to spend time with their wheels off the ground by performing aerial stunts. You’ll find these ridden mostly by the young (or young at heart) at a designated bike park.

Hardtail or Full Suspension?

Up until the early 1980s, all mountain bikes were fully rigid: They had no suspension to soften the ride and improve control. Today, you have a choice of supsensions—none, hardtail or full suspension.


Hardtails have a suspension fork attached to the front wheel only (or a single arm called a “lefty” on some Cannondale models). Front suspension reduces your hand and arm fatigue. It also improves steering and control as you negotiate rough trail surfaces.

Basic suspension forks function by using a wound steel coil spring. High-end bikes use air-sprung forks that are lighter and more adjustable.

Choose a hardtail if: you want an affordable first mountain bike; a single bike for all purposes; a bike for occasional trail use; or a bike for advancing your riding skills.

Shop REI’s selection of hardtail mountain bikes.

Full Suspension

On these bikes, both wheels are suspended. The front is suspended the same way as on a hardtail bike. The rear is suspended by the use of a pivoting frame—the rear wheel is attached to this frame and a rear shock absorber. Full suspension comes at a higher cost and sometimes added weight, but it increases comfort and reduces fatigue for the rider. It also offers more bike control when at higher speeds on difficult terrain.

Choose full suspension if: you want a bike dedicated for dirt trail riding; want to ride faster with more control in difficult terrain; have a bike that is easier on your joints and muscles; ride enough to warrant the higher cost;.

For more information, see the REI Expert Advice article, Understanding Bike Suspension.

Shop REI’s selection of full-suspension mountain bikes.

Wheel Size

26 inch

In the not too-distant past, all mountain bikes were equipped with 26” wheels. It is still a popular wheel size, but now when you walk into a bike shop and inquire about mountain bikes, you are likely to be asked, “26 inch or 29 inch?”

29 inch (“29ers”)

Bigger wheels have become quite popular. A 29" diameter is heavier (more rim, more rubber) and a little slower to accelerate, but it offers better momentum once rolling (more progress for less effort); a larger contact area on the trail (more grip, less slide); and a higher “attack angle”—meaning the wheel rolls over trail obstacles easier.

Tip: 29ers can fit most riders but should definitely be given serious consideration by a taller rider, especially if it is for use on both dirt and pavement.

Note: 26" and 29" wheel sizes are not interchangeable on a frame, as frames and suspension are designed to accommodate a specific wheel size.

For more information, see the REI Expert Advice article, 29er Mountain Bike Basics.

24 inch

Kids’ mountain bikes typically have 24" wheels to accommodate the shorter legs of children. Most are less-expensive versions of adult bikes with simpler components. Generally speaking, these suit kids ages 10 to 13, but this depends more on the size of the child than the age. Younger/smaller children can get started biking with 20" wheels.

Shop REI’s selection of kids’ mountain bikes.

Frame Materials

The frame influences a bike's weight, strength, longevity, ride quality and price.

Aluminum alloy is the most common frame material on mountain bikes. Some more-expensive models have lighter aluminum frames as a result of the manufacturer expending more dollars and effort in the selection of materials, tubing design and the manufacturing process.

Other frame materials include steel, titanium and carbon fiber. Steel is tough, inexpensive and offers a smooth ride, but is relatively heavy for a mountain bike. Titanium is light and strong but too expensive for all but high-end mountain bikes. Carbon fiber is fairly common on cross-country bikes and high-end mountain bikes due to its strength and light weight, but it is relatively expensive because of its labor-intensive manufacturing.

For more information, see the REI Expert Advice article, Understanding Bike Frame Materials.


Components refer to all the parts attached to the bike frame, including:

  • Drivetrain (crank arms, front chainrings, rear cassette, chain, derailleurs and gear shifters)
  • Suspension
  • Wheels (rims, hubs, axles, spokes)
  • Brakes

Manufacturers mix and match components based on each model’s riding purpose, price and the intended user, so you often see components from a variety of brands attached to a bike.

The low end of a model series will feature an aluminum frame with economical components. This is intended for the buyer on a tight budget who wants a bike for occasional or light use.

As you go up in price, quality (more durability, enhanced function, less weight) goes up. The top-end bike in a model series may feature a carbon-fiber frame with the best available package of components.

Component Packages

Shimano and SRAM are the most popular component suppliers, especially of drivetrains. The table below offers a rough comparison of their current component packages.

Intended Use Shimano SRAM
Basic model Acera and Altus X3
Basic model Alivio X4
Entry level for dirt trail riding Deore X5
Mid-range level SLX X7
High-end enthusiast level Deore XT X9
Pro race level XTR X0 and XX


Disc brakes have replaced rim brakes on all but entry-level mountain bikes.

Disc brakes: These feature brake pads that grip onto a brake rotor mounted to the wheel hub. Disc brakes come in 2 versions: Hydraulic disc brakes offer more progressive and stronger braking with less finger effort, and they self-adjust for brake pad wear. Cable-activated (mechanical) brakes need manual adjusting as the pads wear.

  • Advantages: More consistent braking in all conditions; much cheaper to replace a worn rotor than a whole wheel. Best for steep or wet terrain; less finger strain.
  • Disadvantages: More difficult to inspect pad wear and replace pads. Hydraulic brakes are more expensive to service.

Rim brakes: Common on entry-level mountain bikes, rim brakes feature pads that grip onto the wheel rims.

  • Advantages: Economical; easy to observe brake pad wear and replace worn pads.
  • Disadvantages: Gradually wears out the wheel rim, requiring the wheel to be replaced; less stopping power than disc brakes; less effective in wet or muddy conditions; requires more finger effort on the levers to brake aggressively.


The number of gears is a result of the number of front chainrings multiplied by the number of sprockets on the rear hub. Typical mountain bike gearing:

Total Gears Front Chainrings Rear Sprockets Comments
1 1 1 Single speed means less weight, mechanical simplicity.
21 3 7 Kids’ bikes have a lower range of gears than adult bikes.
18 2 9 More often seen as an aftermarket setup.
20 2 10 Becoming common on light, high-end bikes.
24 3 8 Typical of entry-level mountain bikes.
27 3 9 The most common mountain bike gearing arrangement.
30 3 10 The latest trend; still mostly found on high-end bikes.

Less important than the number of gears is the range of gearing, from lowest to highest. This influences the steepness of the grade (both uphill and downhill) that you can pedal efficiently without running out of gears. An 18-speed bike may cover the same range of gears as a 27-speed bike, but with fewer increments between highest and lowest. However, it is generally true that the more gears you have, the wider the range of gearing from low to high.

The extreme in gearing is a single-speed bike, which attracts some mountain bikers because of its mechanical simplicity and lighter weight. Be prepared to develop strong leg muscles if you choose a single-speed bike.

Tip: Gearing arrangement is rarely a major factor in deciding on a bike unless you are experienced with the various options and have a strong preference towards a particular configuration.


Know what your money can buy or how much money it takes to buy what you need. Here’s a rough guide:

  • $500 to $900: A basic but functional hardtail (26" or 29" wheels) suitable for occasional use on easy to moderate terrain.
  • $900 to $1,500: A hardtail with a lightweight frame and high-end components suitable for regular use on a wide variety of terrain.
  • $1,500 to $2,500: An entry-level full-suspension bike or an entry-level competition hardtail.
  • $2,500 and up: A race-ready hardtail or a good to excellent quality full-suspension bike.

Buying tip: It actually costs less money in the long run to buy a higher quality bike now than it would to buy a less-expensive bike now and upgrade the components later.

At the Bike Store

Armed with the above knowledge, now is a good time to head to REI or other specialty bike retailer to determine your frame size, identify some suitable models and try out a few bikes.

Choose a Frame Size

Ask the sales specialist what size you should be riding. Once determined, it is going to be reasonably consistent between brands and models.

A sales specialist who is experienced in sizing can often tell by looking at your body proportions. He or she also may have access to the bike fit kit, which is used to measure you and determine the right frame size.

In the absence of either of the above, there are a few things you can check:

  • The reach from seat to handlebar: When sitting on the bike, you feel neither too stretched out (the bike is too long) or too scrunched up (the bike is too short) for comfort.
  • Seat height: When sitting on the bike with one foot at the bottom of a pedal stroke, you should have a slight bend in your knee. Disclaimers: The seat post must not be extended beyond the safe minimum insertion level AND the handlebars must not be more than 2” below the seat height. For many riders, the handlebars should be about level with the seat height.
    • Handlebars higher than the seat = a more relaxed riding position.
    • Handlebars lower than the seat = a more aggressive riding position.

A frame’s geometry can also have a major influence on fit. A steeply sloping top tube is going to suit a rider with shorter legs and longer torso and arms (i.e., many men), but not a rider with long legs and a shorter torso and arms (i.e., many women) who need a higher seat position.

A woman’s specific frame is recommended for shorter women, as the reach from seat to handlebars will be shorter and more comfortable than on a men’s bike. This helps to greatly reduce back, shoulder and neck strain and discomfort.

Buying tip: Standover clearance is no longer an accurate way to select a frame size. It used to be that you should have 1” or more of clearance when straddling the top tube with your feet flat on the ground. Changes in frame design and geometry have reduced the relevance of this rule, though you do still need a comfortable amount of standover clearance.

Go for a Test Ride

Ask if you can test ride several bikes. With the help of a sales specialist, you should be able to narrow down your selection to 2 or 3 bikes. Though they may have similar prices and components, each will feel different to ride. Take each on a 5- to 10-minute ride over some varied surfaces, including up a short hill.


In most cases, one bike is just going to feel better for you than the others. You want a bike to feel like a natural extension of your body, not some odd appendage you are constantly fighting.

Buying tip: Ideally, the bike you choose should be suitable for your needs now as well as when your riding time and experience level increase.

Final Steps

Any REI bike shop will give your bike a final mechanical safety inspection before you wheel it out the door. Also, ask for the suspension settings to be adjusted for your body weight. Make sure you have at least the bare essentials for repairs and maintenance: spare tube, patch kit, tire levers, pump, multitool, chain lube and something to carry it all in.

Additional Resources

Maintenance: Take care of your new ride. See the REI Expert Advice article, Bike Maintenance Basics, for a brief primer and ask about upcoming bike maintenance classes at your REI store. Learn how to do basic trailside repairs like fixing a flat tire. Of course, your REI bike shop is always here to help with tune-ups, repairs and upgrades.

Ride suggestions: Where should you ride? Ask your REI sales specialist for a recommendation on a guidebook, trail map or website resource for your local area, or check REI Guidepost.

What to bring: See the REI Expert Advice Mountain Biking Checklist for gear and clothing you should consider taking along.

Skills: Attend a bike skills clinic such as those offered by the REI Outdoor School. Mountain bike skills books can also be helpful.

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