Product Code Database
A mountain bike ( MTB) or mountain bicycle is a bicycle designed for off-road cycling ( mountain biking). Mountain bikes share some similarities with other bicycles, but incorporate features designed to enhance durability and performance in rough terrain, which often makes them heavier, more complex and less efficient on smooth surfaces. These typically include a bicycle fork, large knobby tires, more durable Bicycle wheel, more powerful brakes, straight, wide handlebars to improve balance and comfort over rough terrain, and wide-ratio gearing optimized for topography, application (e.g., steep climbing or fast descending) and a frame with a suspension mechanism for the rear wheel. Rear suspension is ubiquitous in heavier-duty bikes and now common even in lighter bikes. Dropper seat posts can be installed to allow the rider to quickly adjust the seat height (an elevated seat position is more effective for pedaling, but poses a hazard in aggressive maneuvers).
Mountain bikes are generally specialized for use on mountain trails, single track, , and other unpaved surfaces. In addition to being used to travel and recreate on those surfaces, many people use mountain bikes primarily on paved surfaces; some may prefer the upright position, plush ride, and stability that mountain bikes often have. Mountain biking terrain commonly has rocks, roots, loose dirt, and steep grades. Many trails have additional technical trail features (TTF) such as log piles, log rides, rock gardens, skinnies, gap jumps, and wall-rides. Mountain bikes are built to handle these types of terrain and features. The heavy-duty construction combined with stronger rims and wider tires has also made this style of bicycle popular with urban riders and couriers who must navigate through potholes and over curbs.Olsen, J. (1999). Mountain biking. Mechanicsburg, PA: Stackpole Books.
Since the start of the sport in the 1970s, many new subtypes of mountain biking have been developed, such as cross-country (XC), trail, all-mountain, enduro, freeride, downhill, and a variety of track and slalom types. Each of these place different demands on the bike, requiring different designs for optimal performance. MTB development has led to an increase in suspension travel, now often up to , and gearing up to 13 speed, to facilitate both climbing and rapid descents. Advances in Bicycle gearing have also led to the ubiquity of "1x" drivetrains (pronounced "one-by"), simplifying the gearing to one Chainset in the front and a wide range cassette at the rear, typically with 9 to 12 . 1x gearing reduces overall bike weight, increases ground clearance, and greatly simplifies the process of gear selection, but 2- or 3-ring drivetrains are still common on entry-level bikes.
The expressions "all terrain bicycle", "all terrain bike", and the acronym "ATB" are used as synonyms for "mountain bike", but some authors consider them passé.
It was not until the late 1970s and early 1980s that road bicycle companies started to manufacture mountain bicycles using high-tech lightweight materials, such as M4 aluminum. The first production mountain bike available was the 1979 Lawwill Pro Cruiser. The frame design was based on a frame that Don Koski fabricated from electrical conduit and a Schwinn Varsity frame. Mert Lawwill had Terry Knight of Oakland build the frames. The bikes sold for about $500 new and were made from 1979 though 1980 (approximate run of 600 bikes).
The first mass production mountain bike was the Specialized Stumpjumper, first produced in 1981. With the rising popularity of mountain bikes, Randolph (Randy) Ross, executive vice president of Ross Bicycles Inc., was quoted in the New York Times saying I'd say these bikes are one of the biggest things that ever happened to the biking industry. Its basic look constitutes "a total shift in image" for the industry.
Throughout the 1990s and 2000s, mountain biking moved from a little-known sport to a mainstream activity complete with an international racing circuit and a world championship, in addition to various free ride competitions, such as the FMB World Tour and the Red Bull Rampage.
Many new mountain bikes integrate a "full suspension" design known as dual suspension, meaning that both the front and rear wheel are fitted with a shock absorber in some form as the wheel attaches to the bike. This provides a smoother ride as the front and rear wheels can now travel up and down to absorb the force of obstacles striking the tires. Dual suspension bikes of a similar quality are considerably more expensive, but this price increase brings an enormous off-road performance upgrade as dual suspension bikes are much faster on downhill and technical/rough sections, than other forms of the mountain bike. This is because when the wheel strikes an obstacle its tendency is to bounce up. Due to some forward energy being lost in the upward movement some speed is lost. Dual suspension bikes solve this problem by absorbing this upward force and transmit it into the shocks of the front and rear wheels, drastically decreasing the translation of forward momentum into useless upward movement. Disadvantages of rear suspension are increased weight, increased price, and with some designs, decreased pedaling efficiency, which is especially noticeable when cycling on roads and hard trails. At first, early rear suspension designs were overly heavy, and susceptible either to pedaling-induced bobbing or lockout.
There are two main types of mountain bike Disc brakes: mechanical disc brakes and hydraulic disc brakes.
Mechanical disc brakes use a brake cable housed in a brake housing, which connects the brake lever to the brake caliper. When the lever is pulled, it tightens the cable, which in turn actuates the caliper and presses the brake pads against the rotor.
Hydraulic disc brakes, on the other hand, use a sealed hydraulic system instead of a cable. When the brake lever is pulled, it pressurizes the in-compressible brake fluid (typically mineral oil or DOT fluid), which forces the brake pistons to move the pads against the rotor. Hydraulic systems generally provide stronger and more consistent braking performance compared to mechanical brakes.
Bicycle wheel sizes are not precise measurements: a 29-inch mountain bike wheel with a bead seat diameter (the term, bead seat diameter (BSD), is used in the ETRTO tire and rim sizing system), and the average 29″ mountain bike tire is (in ISO notation) 59-622 corresponds to an outside diameter of about 29.15 inches (740 mm).
622 mm wheels are standard on road bikes and are commonly known as 700C. In some countries, mainly in Continental Europe, 700C (622 mm) wheels are commonly called 28 inch wheels. 24 inch wheels are used for dirt jumping bikes and sometimes on freeride bikes, rear wheel only, as this makes the bike more maneuverable. 29 inch wheels were once used for only cross country purposes, but are now becoming more commonplace in other disciplines of mountain biking. A mountain bike with 29″ wheels is often referred to as a 29er, and a bike with 27.5-inch wheels is called a 27.5 Mountain bike or as a marketing term ″650B bike".
Wheels come in a variety of widths, ranging from standard rims suitable for use with tires in the 1.90 to 2.10 Inch (48 to 53 Millimetre) size, to widths popular with freeride and downhill bicycles. Although heavier wheelsets are favored in the freeride and downhill disciplines, advances in wheel technology continually shave weight off strong wheels. This is highly advantageous as rolling weight greatly affects handling and control, which are very important to the technical nature of freeride and downhill riding. The widest wheel/tire widths, typically 3.8 in (97 mm) or larger, are sometimes used by icebiking who use their mountain bikes for winter-time riding in snowy conditions.
Manufacturers produce with a wide variety of tread patterns to suit different needs. Among these styles are: slick street tires, street tires with a center ridge and outer tread, fully knobby, front-specific, rear-specific, and snow studded. Some tires can be specifically designed for use in certain weather (wet or dry) and terrain (hard, soft, muddy, etc.) conditions. Other tire designs attempt to be all-around applicable. Within the same intended application, more expensive tires tend to be lighter and have less rolling resistance. Sticky rubber tires are now available for use on freeride and downhill bikes. While these tires wear down more quickly, they provide greater traction in all conditions, especially during cornering. Tires and rims are available in either tubed or tubeless designs, with recently (2004) gaining favor for their pinch flat resistance.
Tires also come with tubes, tubeless and tubeless-ready. Tires with tubes are the standard design and the easiest to use and maintain. Tubeless tires are significantly lighter and often have better performance because you can run them at a lower tire pressure which results in better traction and increasing rolling resistance. Tubeless-ready tires are tires that can use tubes or go tubeless. A liquid sealant is used without the tube to secure the seal to the rim. Popular tire manufacturers include Wilderness Trail Bikes, Schwalbe, Maxxis, Nokian, Michelin, Continental, Tioga, Kenda, Hutchinson, Specialized and Panaracer.
|
|
