Development of New Technologies Specialized for Mountain Bikes

In 1982, Shimano released DEORE XT, a components series dedicated to mountain bikes. Although the majority of the bicycle industry was not yet interested in mountain bikes, mountain bikers enthusiastically supported DEORE XT, which was a product developed by reflecting their views. From the latter half of the 1980s to the 1990s, explosive mountain bike booms took place in various regions in the world, and DEORE XT fully supported these booms. DEORE XT has since exuded a significant presence as a representative components series for mountain bikes.

STORY
SERIES

STORY

DEORE XT Rides the Wave of the Times

The history of components dedicated to mountain bikes began with a phone call made by Yoshizo Shimano, who was President of Shimano American Corporation in 1981 (later the 4th President of Shimano Inc.), to the headquarters in Japan. He said that a new wave of riding in which young people rode down mountain slopes was spreading in the suburbs of San Francisco and they even remodeled their bicycles by themselves to improve their riding performance.

Yozo Shimano, then Vice President responsible for the Marketing Division (present President), who received the phone call, started a new project, and collected first-hand information by visiting local mountain bikers while bringing prototypes with him. American mountain bikers wanted robust components that would withstand the impact of hard landings on the ground after unimaginably high jumping. Since mountain bikers dynamically rode through creeks and muddy areas, they wanted waterproof components that would enable bikes to cross such terrain, as well as shifting performance that would withstand mud and dirt, and most importantly, high braking performance. It was not easy to meet their demands; however, after much trial and error, in 1982, the following year, Shimano announced the much-awaited release of a components series dedicated to mountain bikes “DEORE XT.”

In 1986, four years after its release, the M730 series, which incorporated Shimano Index System (SIS), was released. This series later incorporated new functions that would be representative of mountain bikes, including HG cassettes, RAPIDFIRE shifters and the Shimano Pedaling Dynamics (SPD) system. These functions were eventually embodied in the concept of Shimano Total Integration (STI), which was Shimano’s development concept of system components aiming to integrate innovative functions in a user-friendly manner, and served as a driving force for Shimano’s subsequent leaps.

In 1991, Shimano released the flagship mountain bike components series XTR as a racing series. In the meanwhile, DEORE XT continued to exist as a full-fledged mountain bike components series, and at the same time, its range expanded as it was mounted on trekking bikes, which became popular in Europe at that time.

DEORE XT has continued to be a mainstay of Shimano mountain bike components seriess. Currently, a wave of e-bikes is arriving in the mountain bike field. Shimano will provide perfect solutions also to this new world capitalizing on knowledge cultivated in the past development of mountain bike components.

SERIES

1982

DEORE XT M700 series

In terms of ease of use, Shimano put a lot of thought into designing the shift and brake levers. A thumb shifter was adopted, which enabled the rider to shift with the thumb or index finger while keeping their hands on the handlebar. For the cables, an inner wire with a diameter of 2 mm was used although a wire with a diameter of 1.6 mm was standard for bicycles at that time. This was to improve robustness from the standpoint of practical utility. Shimano developed a shielding mechanism that minimized rattling caused by harsh use conditions and kept mud and water from entering into the sliding parts, and adopted it for each component to enhance resistance of all the components to mud and sand.

1986

SHIMANO DEORE XT M730 series

M730 series incorporated several shifting technologies represented by SIS and BIOPACE II and a high-power rear brake U-Brake, promoting the concept of “total control” as a components series rather than each component. The initially released M730 had a 6-speed drivetrain system, and each component was made of light alloy, offering excellent durability, which emphasized its off-road ability. After the release of this first model, repeated minor changes were made to the 730 series.

1987

SHIMANO DEORE XT M732 series

HYPERGLIDE (HG) gears, which allowed smoother shifting, SIS, which evolved into seven speeds, and the Shimano Linear Response (SLR) braking system, which enhanced braking performance and controllability, were newly added.

1989

SHIMANO DEORE XT M735 series

Shimano developed the RAPIDFIRE shifter by improving conventional shifting levers. As its name suggested, it enabled quick shifting only with the thumb as the downshift/upshift levers were placed under the handlebar. Furthermore, since the levers were designed to always return to their initial positions after gear change and enabled the rider to shift up to six gears at once, the RAPIDFIRE shifter was especially beneficial in scenes where riders were required to make an instant decision. HG cassette sprockets, SG chainrings and SIS, which were integrated with SLR, led to the concept of STI.

1994

SHIMANO DEORE XT M737 series

It was upgraded to an 8-speed drivetrain system. Equipped with RAPIDFIRE PLUS shifters, with improved operability from the RAPIDFIRE shifters adopted in M735. To make the drivetrain system more compact, the HyperDrive-C system was adopted, in which the number of outer gear teeth of the crankset was decreased from the traditional 48T to 42T and the number of gear teeth of the top gear of the cassette sprocket was decreased to 11T.

1995

SHIMANO DEORE XT M739 series

V-BRAKE, developed for XTR M950, was adopted in DEORE XT. V-BRAKE achieved stronger braking force and higher control than previous brakes. Furthermore, it succeeded in eliminating problems resulting from irregularities of the rim and dive-in since the brake shoe made contact with the rim at a right angle.

1998

SHIMANO DEORE XT M750 series

Adopted a black and silver orthodox design as an authentic mountain bike components series. It was upgraded to a 9-speed MEGA 9 drivetrain system. The rear derailleur achieved improved quiet performance and durability by using 11T pulleys. A hydraulic brake was adopted for the first time in a Shimano mountain bike components series. Adopting a dual diameter opposed four-piston caliper design and mineral oil achieved high braking force and control.

2003

SHIMANO DEORE XT M760 series

Responding to the spread of mountain bikes, a variety of specifications according to riding style started to be offered. Also, a dynamic design that made a clear departure from previous models was adopted. Features from the functional aspect included: Dual Control Lever system, which enable both gear shifting operations and brake control with one lever, and the MONO-BODY caliper, which was machined from a forged block to achieve high stiffness and light weight.

2007

SHIMANO DEORE XT M770 series

DEORE XT marked its 25th anniversary. As the way of enjoying mountain bikes was becoming ever more segmented, to offer greater versatility, Shimano added specifications for cross bikes. This series included SHIMANO SHADOW RD, which was intended for more aggressive riding, helping especially to prevent damage due to obstacles. Other results of engineering innovation were also incorporated, including weight reduction, durability improvement of parts and quick shifting. Furthermore, the Dyna-Sys 10-speed drivetrain system was adopted in 2010.

2012

SHIMANO DEORE XT M780 series

Two models in silver and black specifications were announced. This series inherited the Dyna-Sys 10-speed drivetrain from the M770 series, and adopted ICE TECHNOLOGIES, which dramatically improved the heat-exchange efficiency of the disc brake system. Adopting a radiation fin for the brake pad and aluminum materials with high thermoelectric efficiency for the rotor achieved high braking force and noise reduction.

2015

SHIMANO DEORE XT M8000 series

Upgraded to a Dyna-Sys 11-speed drivetrain system. It offered more aggressive specifications with the eye on Enduro. The crankset in a new 3D composite chainring construction featured reduced weight and improved durability. It was available in single, double and triple chainring types. The ergonomic design offered a comfortable ride even over extended periods of cycling and achieved efficient shifting and smooth riding.

2016

SHIMANO DEORE XT M8050 series

Introducing the DI2 shifting system enabled high-accuracy electric shifting by computer (SEIS: SHIMANO ELECTRONIC INTELLIGENT SYSTEM). SEIS allowed synchronized shifting in the front and rear derailleurs, achieving selection of the optimum gear position combination and smooth and quick response. The system information display, which provided an at-a-glance view of the present status, enabled the rider to enjoy more comfortable, safe and secure riding.

2019

SHIMANO DEORE XT M8100 series

Upgraded to a 12-speed drivetrain system. Adopting the sophisticated RAPIDFIRE PLUS shifter has further improved operability. This series features a drivetrain that can be used for aggressive riding styles with peace of mind, is light weight, and has an expanded range of settings customized according to the preferences and riding style of the rider.