A mountain bike should reward the rider with maximum fun on the trail. For this to work, all parts of the bike must form a sensible unit and fit together.
- Grips, pedals and saddle: They establish the connection to the rider and are fundamental to the seating position and riding comfort.
- Drive or gearstick: The drivetrain includes a rear derailleur, chain, cassette, gear lever and crank, which should guarantee the necessary propulsion in every situation.
- Chassis: The suspension fork and shock absorber not only cushion the bumps on the trail, but also press the wheels and tyres to the ground and generate traction.
- Tyres: The lugs of the tyres briefly form a unit with the trail and determine grip and safety.
- Frame: It is the basic framework, connects all components with each other and gives the bike its character.
But what do the individual components need to be able to do and how do they influence the riding behaviour of a mountain bike? We provide tips and advice on which components are worth investing a little more in.
The frame
The frame forms the basis of every mountain bike. The geometry and material generally remain the same across the majority of the price range. The cheaper bikes are usually Made from aluminium and the expensive models are often made of carbon fibre. Products made from this high-tech fibre weigh less than aluminium with the same or greater rigidity. Carbon is therefore perfect for building lightweight mountain bikes. However, the black high-grade plastic is more expensive than the light metal due to the complex manufacturing process. You should also check the frame for cracks after a fall. If there is one: Do not continue riding! There is a high risk of the frame breaking. With aluminium frames, a dent is usually not a safety risk.
The suspension on a mountain bike
With the exception of hardtails with rigid forks and fat bikes, all mountain bikes are equipped with suspension elements. They provide more comfort and grip. While a hardtail only has a suspension fork, there is also a shock absorber in the rear of a full-suspension bike. Most mountain bikes are fitted with air suspension elements. The spring stiffness can be adjusted to the rider's weight via the pressure in the air chamber. The rebound speed can be adjusted separately as standard. Higher-quality models also have a compression setting (compression speed). In order to pedal uphill as efficiently as possible, the shock on the fully should have a lockout or a platform. The small lever prevents the shock from bobbing when pedalling. It is worth investing a little more money in suspension elements. The differences in function are enormous. Shocks with steel springs dampen a little more sensitively, but due to their significantly higher weight, they are generally only found on enduro or downhill bikes. >> here you can find more information and tips on MTB suspension forks
The tyres on the mountain bike
The tyre is the only point of contact between the mountain bike and the ground. The tread, the rubber compound and also the width therefore have an influence on the handling behaviour of the entire bike. Although wide downhill tyres increase grip, they also increase rolling resistance. This gives you more safety on rough terrain, but you have to pedal harder on a longer tour. Although lightweight cross-country tyres roll much better, they offer less grip due to their narrow profile and are also more susceptible to punctures. Manufacturers usually offer their mountain bike tyres in different quality levels. However, price-conscious bikers can go for the cheaper models. The increase in performance does not outweigh the additional price, as our Tyre test in BIKE 10/2020 has shown. If you want to get the last bit out of your tyres, you should switch to a tubeless setup. This reduces the weight and the risk of punctures even with low tyre pressure.
The brakes on a mountain bike
Hydraulic disc brakes have established themselves on mountain bikes. And rightly so, in our opinion. They are powerful and less susceptible to wet conditions than rim brakes. Either two or four pistons per brake calliper are used for deceleration. Four-piston brakes provide more stability and are particularly useful on downhill-orientated bikes and for heavy riders. The diameter of the brake disc and the brake pad are also decisive for the braking power. When it comes to brake pads, you can usually choose between sintered pads and organic pads. Due to the metal content in sintered pads, the brake requires a certain temperature to develop its full power. In return, they last longer on long descents than organic pads and wear out more slowly. Organic pads develop their full braking power at the start of braking, but overheat more quickly. Organic pads also wear somewhat faster. The diameter of the brake disc also has an effect on braking performance. 180 millimetre discs are standard. Large 200 mm discs decelerate slightly better. Lightweight racers also use 160 millimetre discs for weight reasons.
The wheels on the mountain bike
The lighter the wheels and tyres (= rotating mass), the faster a mountain bike can accelerate. Inexpensive bikes are often fitted with heavy wheels. There is potential for tuning here, as a lot of weight can often be saved on wheels. The rim width (inner rim width) is also important when choosing wheels. This is because a wide rim makes it possible to run lower air pressure and thus generate more comfort and grip. A rim width of 30 millimetres is perfect for modern mountain bikes, while 25-30 millimetres is also ok for sporty hardtails and race fullys.
The drive on the mountain bike
With a few exceptions, derailleur gears have established themselves on mountain bikes. One chainring at the front and twelve sprockets at the rear of the cassette provide an enormous range and ease of use, as the gears only have to be changed at the rear with these so-called single gears (1x12 gears). Gear systems with two chainrings and derailleur (3x9, 2x10 or 2x11 gears) are only occasionally used on inexpensive bikes under 1000-1500 euros. Even cheap 12-speed drivetrains such as the Shimano Deore or the Sram NX Eagle change gears reliably. The differences to the expensive models are almost exclusively due to the materials used and the lower weight. Electronics are also becoming increasingly popular on mountain bikes. Sram is not only equipping the top model with wireless technology, but the mid-range GX drivetrain is now also available as an AXS version.
Vario seatpost, pedals & co.: Attachments on the mountain bike
One lowerable seat post is now standard equipment on trail bikes, all-mountain bikes and enduro bikes - and that's a good thing. Vario seatposts are also increasingly being used on race bikes and hardtails. This allows the saddle to be lowered by up to 200 millimetres in a flash. This is practical, as it provides more freedom of movement on the trail and in steep sections. If you press the remote control on the handlebars, the seat post extends and you can pedal efficiently. Marathon bikers usually do without the comfort of a Vario seatpost in order to save weight. Because every gram counts, especially for racers.
The combination of Handlebars and stem is crucial for the riding experience. Handlebars that are too wide can lead to sore wrists. If the handlebars are too narrow, you lose control. The stem also affects the riding position. A long stem makes the riding position more elongated and sporty. A short stem makes the steering behaviour more direct and you sit more upright on the bike.
Pedals are rarely fitted to new mountain bikes. But why actually? Some bikers feel comfortable on platform pedals, others prefer to click their shoes in. With clipless pedals, the shoe is firmly connected to the counterpart in the pedal with a small metal plate in the sole. The foot is released again by rotating it sideways. You have to get used to this to avoid tipping over with your bike in front of the ice cream parlour. But once you have got used to getting on and off the bike, you can climb hills much more efficiently. What's more, your feet stay in position even in rough stone fields or over root carpets. Clipless pedals are available with and without a cage. The aluminium or plastic surround provides a larger contact surface and an even firmer footing on the pedal. Of course, this also increases the weight. Flat pedals do not have a click mechanism, but usually have small metal pins that drill into the soles of the shoes. The shoe is therefore not firmly attached to the pedal. Many manufacturers offer special flat pedal shoes for this purpose. For beginners, mid-height trainers with a light profile and good lateral support are also sufficient. Overall, flat pedals make it easier to get on and off the bike, but are less efficient when climbing. In addition, your foot can quickly slip on rocky terrain. Choosing the right pedal is therefore a matter of taste. To find the right pedal for you, there's only one thing to do: try it out!
