Buying your first mountain bike; it’s a big moment, and it can be tricky if you don’t know what you’re looking for.

That’s why we’ve put together this easy to digest guide to how to buy your first mountain bike – covering everything from the very basic to the easily overlooked.

The important thing about getting your first bike, whether that be a downhill bike, a trail bike, a cross-country bike, a freeride bike, or whatever, is that it's a good bike. The guide below should help you get the best mountain bike for you:

How to Buy Your First Mountain Bike: The Basic Options

decathlon how to buy your first mountain bike mtb 8

decathlon how to buy your first mountain bike mtb 8

There are two main kinds of ride to choose from when you’re buying your first mountain bike; a hardtail, so named because it features only a front suspension fork, and a full suspension bike, which features a rear shock absorber as well, providing more control and keeping the bike true while you’re riding rough trails.

The type of bike you choose should be based on the roughness of the terrain you will be riding, the likelihood that you’ll be taking on sizable drops or jumps, and of course, your budget, as full suspension bikes can be quite a bit more expensive than hardtails.

Remember, you’ll have to know how to dress mountain biking in all weather conditions and buy the kit to clean your mountain bike as well, so have a think about this before you set out to buy!

How to Buy Your First Mountain Bike: Hardtail Bikes

decathlon how to buy your first mountain bike mtb 6

decathlon how to buy your first mountain bike mtb 6

Hardtails can be used for most kinds of mountain biking. The bikes are lighter, faster and nippier than full-suspension bikes, and you’ll get more out of every pedal stroke you take.

Of course, hardtails can prove unforgiving if you find yourself in a spot of bother on a rough trail. You’re going to feel every root or rock you pass over in the handlebars.

Hardtails will typically have between 80-150mm of travel, by which we mean the maximum length that the front suspension fork will move when called into action.

  • Cross Country: If you’ll be doing just as much climbing as you will be descending, you’ll want a cross-country bike. These bikes are built around getting as much return as possible from every pedal stroke and feature between 80-120mm of travel.
  • Trail Riding: Hardtails made for trail riding will feature stronger, slightly heavier frames than cross-country bikes, and travel in the region of 120-150mm. This allows them to accommodate for the vibrations that will come through the front wheel and provide more control and grip.

Choosing Your First Mountain Bike: Full-Suspension Bikes

decathlon how to buy your first mountain bike mtb 7

decathlon how to buy your first mountain bike mtb 7

Full suspension bikes are exactly what they say on the tin; they’ve got rear suspension as well as the front suspension fork and are a lot more durable, reliable and smooth.

Full-suspension cross-country bikes feature around 100mm of travel, while trail riding bikes feature around 120-140mm. Though they will be a little heavier than their hardtail counterparts, the design of the bike means you’ll still move speedily in addition to the extra control.

Other types of full suspension bike you may want to consider include:

  • Enduro: Also often called all-mountain bikes, enduro rides tend to have between 150-160mm of suspension, are again slightly heavier, but are even more durable and ride even smoother when the trails get aggressive.
  • Downhill: These are specialist bikes for those who will only be riding downhill. The travel will be between 200-220mm, the bikes will be heavier than the rest and NOT be suitable for uphill riding. These are made for big drops, steep slopes and rough riding. They’ll feature stronger frames, a saddle that will be lower to accommodate a standing position and a smaller gear ratio.

Choosing Your First Mountain Bike: Wheel Size

decathlon how to buy your first mountain bike mtb 4

decathlon how to buy your first mountain bike mtb 4

There are three sizes of wheel to choose from when you're buying a mountain bike - 26 inch, 27.5 inch/650B, and 29 inch - and choosing the right one is crucial for your riding style.

26 inch was the first wheel size to be put on a mountain bike, but the other sizes have become increasingly popular to the point where the majority of riders no longer use a 26 inch wheel.

  • 26 inch wheels: The old timer’s choice, the 26 inch wheel has been around since the beginning of mountain biking. The design allows a lot of manoeuvrability and creativity over the bike, though the bike can struggle to roll over bigger objects and be tough to control.
  • 29 inch wheels: The 29 inch bike is a lot longer than the 26 inch, and so it can take some a while to adjust to the riding position. When they do adjust, their reward is a much higher standard of control, strength and stability while riding, though many find the ride too rigid and tough to manoeuvre.
  • 27.5 inch wheels: Many say the 27.5 inch, or 650b, is the perfect compromise when it comes to wheel size. The 27.5 gives the rider a notably smoother, more controlled ride than the 26 inch, but doesn’t feel nearly as slow as the 29er. Faster, stronger and more agile than the bigger wheels and a whole lot more fluent than the smaller.

How to Buy Your First Mountain Bike: Gear Ratio

decathlon how to buy your first mountain bike mtb 1

decathlon how to buy your first mountain bike mtb 1

You’ll find a wide range of gear ratios available across all mountain bikes, with anything from one, two or three chainrings available.

The more chainrings you have, the more gears you’ll have to flick through when riding. Triple chainrings will add more weight to your bike, require higher maintenance and feature some overlap though, so a double chainring set up if possibly best for beginners.

A single set up is preferred by a lot of riders who don’t do much uphill climbing though, and it is very easy to maintain.

How to Buy Your First Mountain Bike: Frame Sizes

decathlon how to buy your first mountain bike mtb 2

decathlon how to buy your first mountain bike mtb 2

If there’s one thing that’s crucial when you’re buying your first mountain bike, it’s getting the right size of ride. Get the wrong size and you’ll end up struggling to control the bike, straining to do so and possibly injuring yourself. So, how do you know?

If we’re being honest, the best bet for this is to ask the customer assistants in the bike shop when you go in. They’ll know the bikes and sizes back to front and should be able to help you out.

Most bikes are listed either by frame size or simply in the standard small, medium or large framework. Roughly, these are the sizes of bike that will suit each rider:

  • An extra small bike will be for someone 135-150cm
  • A small bike will be for someone 150-165cm
  • A medium bike will be for someone 165-173cm
  • A medium/large bike will be for someone 173-176
  • A large bike will be for someone 173-176cm
  • A large/extra large bike will be for someone 180-184cm
  • An extra large bike will be for someone 184-195cm

You should also check out if the manufacturer of the bike has their own size chart, and remember, just because you’re a small in t-shirt size doesn’t mean you’re a small bike size as well!

Choosing Your First Mountain Bike: Frame Materials & Geometry

decathlon how to buy your first mountain bike mtb 3

decathlon how to buy your first mountain bike mtb 3

There are three common kinds of mountain bike frames available across the range. They are:

  • Steel: The traditional material for mountain bike frames, steel is brilliantly durable and rust resistant, though it is heavier than many of the alternatives.
  • Aluminium: This has become the most popular material for making mountain bike frames. Aluminium is not as durable as steel, but it is significantly lighter, and again resistant to rust.
  • Carbon: Carbon frames came onto the market relatively recently but have revolutionised the mountain bike frame. Designers are able to shape the material and form different shapes that impact the dynamics of the bike. Carbon frames are super lightweight while also stronger than steel frames. The drawback is that they cost a lot more.

Traditionally, women’s bikes will be largely similar to the man’s – certainly in terms of suspension, wheels, brakes, chainstay, etc – but where they do differ is in frame.

Women’s frames tend to have shorter top tubes, meaning the saddle and handlebars are closer together to accommodate the average build of a woman. The saddle will also be set up differently.

The head angle on the frame of the bike is also something worth looking out for. The head angle is the angle between your head tube/fork and the floor.

The closer the fork is to being parallel to the ground, the easier it'll be to go downhill, but the tougher the steering will be. The steeper the head angle on the bike, the better the bike will be at climbing.

Choosing Your First Mountain Bike: Brakes

decathlon how to buy your first mountain bike mtb 6

decathlon how to buy your first mountain bike mtb 6

The majority of modern mountain bikes will come equipped with disc brakes, and you shouldn’t settle for anything else.

The be-all end-all of the modern mountain biking brake, these are now standard across most rides. They come in two types; hydraulic and mechanical. Hydraulic brakes use fluid to transfer the force from level to calliper to stop the wheel, like cars or motorcycles, while mechanical brakes use a cable pull system similar to old-fashioned rim brakes.

Hydraulic brakes have more power than mechanical brakes, but mechanical brakes are easier to maintain and cheaper. Still, the benefits of hydraulic definitely outweigh the negatives.

Choosing Your First Mountain Bike: Other Things To Consider

decathlon how to buy your first mountain bike mtb

decathlon how to buy your first mountain bike mtb

  • Look out for bikes that come with dropper posts. This allows you to adjust your saddle a lot easier, which is brilliant for making sure you’re always at the right height going uphill or down.
  • Remember, if you’re only just buying your first mountain biking, and so are only just getting into mountain biking, you probably don’t need the most expensive ride on the market. That frame that could save you valuable seconds won’t make a difference to how quickly you progress and enjoy the sport – look for a strong, reliable bike that won’t let you down with mechanical faults and you’ll be more than happy.
  • Don't let your friends trick you into thinking BMX or road cyclist are funner. Mountain biking is what you need in your life!

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