A man riding his mountain bike over rocky terrain

How to choose a mountain bike: a buying guide

Mountain bikes come in all shapes and sizes. If you’re unsure what to look for when buying your first mountain bike, here are some tips to help you out.

With the inevitable march of technological innovations, venturing into the world of mountain biking can be intimidating for many beginners. Where do you begin with so many different kinds of bikes, brands, features and materials? This mountain bike buying guide will look at what you need to know when shopping for your first mountain bike and the seven essential features your bike needs to have.

While spending a small fortune on a bike is definitely an option, you don’t need to break the bank to get out riding in the hills. But there are some key things you need to know before parting with your well-earned cash to ensure you get the most for your money.

When choosing your mountain bike, you’ll need to consider how long your rides will likely be and the type of slopes you’ll tackle. You might want to start on gentle inclines and descents to get yourself used to the joy of mountain biking. Or, if you’re a thrill-seeker, you might prefer less pedalling and more downhill fun. Whatever you fancy, it’s essential to have the right mountain bike.

riding through a grassy mountain terrain

The amount of time you spend in the saddle is a key factor when choosing your mountain bike and what features it needs to have.

For rides of less than an hour
If your rides aren't very steep and are on easy ground, without too many obstacles, you'll want a bike with the following:
- An 80mm suspension fork for comfort and safety
- Knobbly tyres to provide extra grip
- Gears to help you adapt to the steepness of climbs and descents

For rides of between 1 and 3 hours
For the 90-minute option, we have a favourite. Check out the Rockrider St 100 Mountain Bike for an incomparable experience for rough rides in dry weather.

For rides of more than 3 hours
On more challenging terrain, go for a bike with the following:
- An aluminium frame with variable thicknesses or a carbon frame optimises the bike's weight, rigidity, and performance.
- Air suspension to improve shock absorption and for more accurate adjustment
- A single chainring system for faster and more effective gear shifts

On winding, rolling terrain
Your bike will need the following:
-Disc brakes that are effective in all weather conditions
- Suspension with an 80 to 100mm travel

How Big are the Hills?

There are several types of mountain bikes on the market, and the size of the hills you’ll be riding will play a part in choosing which bike to go for. Cross-Country or Trail centre riding? Let’s go through the two disciplines in a little more detail so you can recognise the most common characteristics of each category to help you choose a mountain bike that is best suited to your needs.

Cross-Country
Cross-country mountain bikes are all about going fast and require intense effort to cover rolling and steep trails. The hardtail cross-country bike looks like a classic mountain bike first did in the 1980s, though they’ve significantly evolved over the decades. XC mountain bikes come in full-suspension or hardtail designs — hardtails can be a more affordable entry into cross-country. The frame geometry, suspension and materials make XC mountain bikes light, responsive and optimised to improve your race time.

Cross-country mountain bikes are usually made of carbon fibre and focused on minimising weight. They typically have 100mm of suspension travel to maximise pedalling efficiency—sometimes less. An XC mountain bike is for you if you want to go fast and aren’t overly concerned about comfort. But if you’re looking for something a little more comfortable and easy to ride, you might consider an all-mountain bike instead.

Trail MTB’s
A Trail MTB aims to climb and descend anywhere, tiring yourself out on the uphills and enjoying an adrenaline rush on the downhills. If comfort and an enjoyable ride are more important to you than performance, opt for a bike with both front and rear suspension for those long rides.

Extended travel, more relaxed geometry, and tough components separate these bigger bikes from their siblings. They come into their own when the trail gets steeper, descents are longer and rougher, and the jumps get bigger. So, if you want a bike that will be more comfortable on descents, no matter what you run into going downhill, then an all-mountain bike could be the one for you. But consider a cross-country mountain bike if you want something more efficient on climbs or want to get into racing.

man riding the 29-Inch Hardtail Mountain Bike Rockrider XC 100

29' inch Hardtail Cross Country Mountain Bike

Unleash adventure with the 29-Inch Hardtail Mountain Bike Rockrider XC 100!
This mountain bike has been designed for those looking to start cross-country (XC) mountain biking. Engineered by Decathlon's experts, this mountain bike delivers superior performance and efficiency with its Shimano 1x11 drivetrain. The 29-inch wheels provide a smooth ride, while the SR Suntour XCR 100mm fork ensures uncompromised control.

Crafted with a durable yet lightweight aluminium frame, it easily tackles any terrain. The Tektro TKD 32 hydraulic disc brakes offer optimized stopping power. Stand out on the trails with this bold, sleek design as you elevate your off-road adventures with the Rockrider XC 100 as your trusted companion.

7 Features to look for in a mountain bike

While it’s tempting to pick up a cheap mountain bike in a discount store or online if you’re new to cycling, it will likely have a weak, heavy frame made from low-quality steel rather than a lightweight aluminium or carbon fibre frame. And it will generally have poor-quality components that won’t last very long if you take your bike on challenging terrain.

So even if you’re a beginner, it’s worth investing a little more money in your new mountain bike, so you get a quality bike that lasts to guarantee a good riding experience. That being said, you can get a lightweight, good quality mountain bike for as little as £229.99 at Decathlon, so it doesn’t have to break the bank.

Spending a little more will get you a lighter bike, making getting up hills much more accessible. And going top-end will bring even greater weight savings, smoother gearing, and better-quality materials and components.

Let’s take a look at seven essential features your first mountain bike should have:

How to Choose a Mountain Bike: A Buying Guide

1. Disc Brakes

Disc brakes are an essential part of the modern mountain bike. With superior stopping power and reliable all-weather breaking, they have all but replaced rim brakes.

Choosing a first bike with rim brakes to save on cost means you can never install or upgrade to disc brakes. The mounting points necessary for disc brakes come as a part of the frame and will not be present on a bike with rim brakes.

You can choose either hydraulic or mechanically operated disc brakes. The former provides more stopping power, whilst the latter is more cost-effective. Don’t forego this all-important feature for supreme stopping power on the trails.

2. A Derailleur Hanger

Crashes are inevitable when you begin trail riding. A derailleur hanger is one of the most important things to look for in a beginner bike, which connects your derailleur to your frame. Designed to break upon a heavy impact, they will sacrifice themselves to save your frame!

A bike with a derailleur that mounts directly onto the frame is a warning sign. They leave you vulnerable to irreparably damaging your frame upon impact. Derailleur hangers are cheap and easily replaced, so don't buy a mountain bike that doesn't have one.

3. Quick release wheels

Flat tyres are common on the trails and inevitable in mountain biking. So when you have a puncture, you’ll want a quick-release lever to quickly and effortlessly remove your wheel.
Many cheaper mountain bikes will use nuts to secure the wheel, meaning you’ll also need to carry the correct tools out on your rides with you. This can be inconvenient, and time-consuming for you and your riding partners in the event of a puncture.

4. Threadless Stem

Identifiable by pinch bolts, a threadless stem is essential to any mountain bike. When riding over rough terrain, the stem can take a hammering. And if damaged, a one-piece stem can be hard to replace as you are limited to old, unreliable parts.

Threadless stems are easy to service and replace while offering a much tougher design to handle the rigours of off-road riding.

5. A Modular Crank and Chainring

When it comes to crank and chainring assembly, you should avoid a bike where they are riveted together. Ideally, they should consist of several independent pieces bolted securely together.

In cases where they consist of one large piece, a crash that causes damage means that the entire set has to be replaced. Don’t buy a bike with an all-in-one crank and chainring system to avoid this costly process.

6. Hardtail or Full Suspension?

A mountain bike with both front and rear suspension may be out of the price range of most seeking their first mountain bike.

Hardtail bikes—those with only a front suspension—are often the best choice as a first bike. Not only are they cheaper, but they’re also great for improving your skills. As a newcomer, you’ll learn how to manoeuvre the bike better, and a hardtail bike will force you to choose a better line on the trail - forcing you out of the saddle more often.

Beginner riders generally won’t maximise the potential of a high-end bike with full suspension, so it might be better to hone your skills on a hardtail first.

7. The Frame Size

Choosing the right frame size for your mountain bike is essential to ensure a comfortable and enjoyable riding experience. An ill-fitting frame can lead to discomfort, decreased control, and even potential injuries.

To determine the correct frame size, measure your inseam and compare it to the manufacturer's sizing chart. Most brands provide size recommendations based on rider height and inseam measurements. Keep in mind that different bike models might have slightly varying geometries, so test-riding the bike before making a purchase is always a good idea. When straddling the bike with both feet flat on the ground, there should be a few inches of clearance between you and the top tube. Additionally, pay attention to the reach and stack measurements, as they influence your riding posture and overall comfort. A properly sized mountain bike will allow you to tackle trails and enjoy your rides confidently.

Choosing the Best Mountain Bike

When it comes to choosing the best mountain bike, several key factors should be considered to ensure you find the perfect ride for your needs. First and foremost, think about your riding style and the type of terrain you'll be exploring. Cross-country riders may prefer a lightweight and efficient bike, while downhill enthusiasts might prioritise sturdy suspension and durable components. It’s rare and almost impossible to find a mountain bike that has it all, especially at a low price.

Next, assess your budget and look for a bike that strikes the right balance between performance and cost. Remember, you can’t have professional performance and quality at a low price and if you find an offer trying to promise you anything of the sort, it’s probably too good to be true.

Always opt for a frame size that fits you well, as comfort and control are crucial during off-road adventures. You’ll also want to pay attention to the bike's suspension system, brakes, and gears, as these components greatly influence your overall riding experience. Lastly, read reviews, test ride different models, and seek advice from experienced riders to make an informed decision.

Why not pop into your nearest Decathlon store and speak to an expert who can help you find the best mountain bike to accompany you on countless thrilling trails?

two people riding a rocky terrain at sunset

We’re Here to Help!

We know it can be a daunting experience as you delve into the world of mountain biking. We stock a wide range of mountain bikes, and by selecting wisely, you can choose a bike that will serve your needs and can be easily upgraded as your skills improve, and you tackle more challenging terrain.

From there, it’s a question of getting faster and fitter, jumping higher and further, and becoming better simply by trying to keep up!

How to choose a mountain bike: a buying guide

How Big are the Hills?

29' inch Hardtail Cross Country Mountain Bike

7 Features to look for in a mountain bike

Choosing the Best Mountain Bike

We’re Here to Help!

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