A mountain bike or mountain bicycle is a bicycle specially invented for off-road terrains like a plateau, mountain, valley, forest and hill. These bikes are made to conquer off-road terrains that have more stringent, thick and durable wheels which provide grip on different terrains and also have powerful brakes, high suspension fork, flat handlebars for upright position and balance.
The countries where mountain biking is extremely in demand are France, USA, Switzerland, Australia, Japan, Germany, New Zealand, Czech Republic, Canada and the United Kingdom. The mountain bikes are mainly built to handle dense terrain. There are various disciplines of mountain biking like cross-country, trail, all-mountain, downhill, freeride, dirt jumping, slopestyle, dual slalom [DS] and so on.
Frame - Frames are the fundamental unit of a bike. These are mainly manufactured from two different materials, i.e. aluminium and the other one is carbon. Aluminium is the most affordable material used in mountain bikes and is lightweight, highly robust and highly popular. Carbon frames, on the other hand, are expensive than aluminium but have the advantage of being shock-absorbent as well as light & durable. The frames consist of six essential parts: one fork, three tubes and two stays.
Wheels - Each mountain bike consists of a pair of wheels which are most crucial in movement. There are two tires in the mountain bike made of rubber and comes in a variety of sizes based on the terrain. The wheels usually have two parts. The inner tire part is filled with pressurized air. And the outer tire is much thicker and has grooves for better grip. The tires are connected to the rims, which function as the outer hoop for the wheels. Rims are predominantly made of aluminium, being the most common material. Cheaper bikes rims are made of steels, whereas expensive bikes rims are made of carbon fibre.
Suspension - Nowadays, the bikes generally come with both front and rear suspension or either front suspension or back suspension individually. Front suspension is found in the front fork whereas the rear suspension can be found in the stays or seat tube. The mountain bikes with rear suspension have a complicated frame design.
Handlebars - The handlebars contain the brake and shift levers and are used to steer the front wheel. There are many types of handlebars, the most common ones to be used in mountain bikes are the flat bars with a little or no upward curve or downward curve.
Brakes - Brakes are one of the most necessary parts of the mountain bike used to maintain the pace, sudden stopping and slowing down. The handlebar brake levers are connected with brake pads or the discs by brake cables. Brake pads are found on the top of both front and rear wheels near the front fork and seat stay. In contrast, disc brakes are fixed around the hub of the wheel but pads are used in this braking system too. Disc brakes are more efficient and offer consistent braking as well as aids in maintaining the rim condition.
Chain and Gears - A set of good gears and chain is the most crucial thing a mountain bike requires. Two sets of gears are used in a good mountain bike, one at the cranks and another at the rear wheel. The front gear has two or three chain wheels and derailleur helps in shifting the chain from one chain wheel to another. Gear shifting results in the change in pedalling power and is proportionally related. The rear gears are smaller than the front gears. The derailleur in the rear wheel is much larger than the front wheel, hanging down from the centre of the rear wheel.
Pedals, Cranks and Bottom Bracket - The pedals and cranks facilitate the chain to spin and move the bike forward. There are two types of pedals. The first type is regarded as a flat pedal. They are most useful for beginners of mountain biking. Second, are the clip pedals with additional pedalling power. For Downhill Mountain biking, shorter cranks are preferred as it has less pedalling power and the bikers have to go over a lot of obstacles.
In the late 1970s and early 1980s, the first mountain bikes were manufactured with reinforced tires and a robust built-in suspension. The frames of the bicycles were prepared with advanced materials to reduce the overall weight. New manufacturers such as MountainBikes, Ritchey and Specialized were the pioneer brands of mountain bikes that popularized the "all-terrain" bicycles. These companies introduced 15 gears gearing system for smooth up-hill riding.
By the 1990s, mountain bikes with 29-inches wheel size became extremely popular. Mountain bikes are very different from road bicycles as these have larger knobby tires and powerful gear system. It has 7 to 9 gears on the back wheel and three gears in the front region. In 1996, the first cross country mountain bike races were included in the Summer Olympics Games. In recent times, the design is mostly evolved with a sophisticated mechanical system. Nowadays, the suspension level has increased up to 8 inches (200 mm), with gearing speeds up to 27.