Mountain bikes: hardtail, full suspension, e-MTB

What is a mountain bike for, and who is it for?

The mountain bike is made for tracks, forest trails and the mountains. You can recognise it by its reinforced frame, its wide knobbly tyres, its suspension fork, its flat handlebar, which gives you leverage to steer the front wheel, and its powerful disc brakes. Leisure riders get a stable, reassuring bike, sporty riders a performance tool uphill and downhill alike, and children a first bike able to follow adults off the road.

Hardtail or full suspension: which mountain bike for which riding?

A hardtail has a suspension fork only. Lighter and easier to maintain, it turns your pedalling effort directly into speed: it is the natural choice for leisure rides, cross-country and controlled budgets. A full suspension bike adds a rear shock: the rear wheel stays glued to the ground, and traction and comfort improve markedly as soon as the terrain gets rough.

Travel, meaning how far the suspension moves, then places the bike in a discipline. At around 100 to 120 mm, a cross-country mountain bike puts efficiency and lightness first. Between 130 and 150 mm, a trail bike bridges climbs and technical descents. From 150 to 180 mm, an enduro bike is designed to link committing descents while climbing back up under its own steam. At around 200 mm, a downhill bike is meant for bike park runs and uplift.

If your rides stay on roads and easy tracks, a gravel bike will be faster, and a road bike faster still on tarmac. For tricks and the race track, BMX bikes are a family of their own.

Electric mountain bikes: what changes

An electric mountain bike, or e-MTB, adds a motor that only works when you pedal. In the UK and the European Union, assistance cuts out at 25 km/h (15.5 mph) and the motor's continuous rated power is limited to 250 W: in law, the bike remains a pedal cycle. In the United States, the federal definition of a low-speed electric bicycle allows a motor of under 750 W and a top speed under 20 mph on the motor alone. The benefit shows on the climbs, where assistance lets you take on more elevation or ride together with friends of different fitness levels.

Battery capacity, expressed in watt-hours, determines range, as do the assistance mode, the elevation and the rider's weight. An e-MTB weighs considerably more than a non-assisted model: its geometry, brakes and tyres are sized accordingly, which makes it a very stable bike on descents.

Wheels, drivetrain and brakes: the technical points

29-inch wheels roll over obstacles more easily and hold their speed better; 27.5-inch wheels make the bike more agile in tight corners. A mixed set-up, 29 inches at the front and 27.5 at the rear, combines the two. Single-chainring drivetrains, often with 12 speeds from Shimano and SRAM alike, have become widespread: fewer adjustments and less risk of dropping the chain. The Shimano CUES range, found on more affordable models, focuses on durability.

Hydraulic disc brakes are now the norm, with larger rotors on downhill bikes and e-MTBs. The dropper seatpost, which lowers the saddle from a lever on the handlebar, changes the way you tackle descents. Tyres, drivetrain parts and components can then be replaced from the MTB wheels and tyres and MTB drivetrain sections, and helmets and shoes are in MTB gear.

What size mountain bike do you need, for an adult or a child?

Brands size their mountain bikes from XS to XL and publish a chart that cross-references your height and often your inside leg. Reach, measured horizontally from the bottom bracket axle to the top of the head tube, tells you about the riding position: the longer it is, the more stretched out and stable you are at speed. Between two sizes, the smaller one favours agility, the larger one stability. Finally, check that the dropper post can go low enough for your leg length.

For a child, wheel size guides the choice. A 20-inch bike generally suits ages 5 to 8, a 24-inch from around 125 cm tall, and a 26-inch suits pre-teens. A light frame matters more than the number of gears: a bike that is too heavy quickly puts off a young rider.

Which mountain bike brand should you choose?

Sunn, a French brand that started out in BMX before becoming a mountain bike reference, now relaunched in Machecoul, in the Loire-Atlantique department, offers the Exact hardtail for cross-country and sporty leisure riding, and the Kern for enduro.

Polygon covers the whole spectrum, from the Siskiu, its full suspension trail range, to the Collosus downhill bike, by way of the Relic, a 20-inch kids' mountain bike.

woom, an Austrian manufacturer that designs only children's bikes, focuses on very light aluminium frames; its Off and Off Air mountain bikes, designed for ages 6 to 14, come with disc brakes and tubeless-ready tyres, with either a rigid carbon fork or a suspension fork.

BH Bikes, a Spanish brand from the Basque Country, has made its mark in electric mountain bikes: the Atom range targets trail riding and the AtomX enduro, alongside non-assisted models such as the Expert or the Spike.

Bemoov, a Belgian brand devoted exclusively to children's bikes, designs light models with aluminium frames and adapted geometry, from the M20 for ages 5 to 8 to the M24 and M26 for older children.

Cannondale pairs the Trail hardtail with the Scalpel, a full suspension cross-country bike, some versions of which get the single-sided Lefty fork, and the Moterra, a full suspension electric mountain bike.

Where can you find a mountain bike on sale?

Mountain bikes whose next version has arrived join MTB clearance, and the latest models listed are gathered in new arrivals. For a mountain bike as for its accessories, also keep an eye on the seasonal sales and Black Friday.

Frequently asked questions

Which mountain bike is best for beginners?

A hardtail with 29-inch wheels, a fork of around 100 to 120 mm, hydraulic disc brakes and a single-chainring drivetrain covers leisure riding and a first taste of cross-country. It is light, easy to maintain and forgiving of line mistakes. A full suspension bike becomes worthwhile when you want to descend faster on rough ground.

Mountain bike or hybrid bike: what is the difference?

A hybrid bike is designed for roads and easy tracks: a more upright position, less knobbly tyres, often mudguards and a rear rack. A mountain bike is built for rough trails, with more capable suspension and more powerful brakes. For rides on greenways, a hybrid is enough; as soon as the terrain gets tougher, a mountain bike is the right choice.

What range can you expect from an electric mountain bike?

No single figure holds for every ride: battery size matters, but so do the assistance mode, the elevation, the rider's weight and the temperature. The same battery therefore lasts much longer in eco mode than in the most powerful mode. For a long ride in the mountains, choose a large battery or a range extender battery if the model accepts one.

Which mountain bike for an 8-year-old?

At this age, the child's height decides between 20 and 24 inches: the latter usually suits from around 125 cm. Sitting on the saddle, they should be able to touch the ground with their toes and reach the brake levers without effort. Choose a light aluminium frame and brakes sized for small hands.

How do you maintain a full suspension mountain bike?

After every muddy ride, rinse the bike at low pressure, wipe the fork stanchions and the shock shaft, then lube the chain. Regularly check the air pressure in the suspension against the sag recommended by the manufacturer. Fork and shock services follow the intervals given in their manuals.