Back then: Shimano MTB gears 1984
It's hard to believe: although the first rear derailleur was introduced in Paris in 1869, gear changes were originally considered unsportsmanlike among racing cyclists. Therefore, the "Tour de France" riders either didn't shift gears at all or they had to loosen the rear hub to change the chain position. It was not until the 1960s that the first serious derailleur gears were developed for racing bikes. Sensation in 1973: the first 10-speed derailleur. In 1981, Yoshizo Shimano (then President of Shimano USA) recognised the needs of the new fun sports enthusiasts in California. The mountain bike movement demanded a robust gear system that could be operated from the handlebars. One year later, Shimano presented the first shifting group for mountain bikers: the Deore XT with a 6-speed cassette. XT became synonymous with high-end in the sport of mountain biking. It was not until ten years later that the XTR groupset took over this position.
Features
The first XT groupset was equipped with a 6-speed sprocket set. Three chainrings resulted in 18 gears -- Technical highlight 1982: "improved rubber seal" and thick 2 mm cables -- Recipe for success: The rear derailleur changes its position via a parallelogram and thus changes gears -- Under tension: The rear derailleur cage had the function of a permanent chain tensioner.
- Type designation: RD-M700
- Year of publication: 1982
- Material: Light aluminium
- Gears: 18
- Weight: 254 grammes
- Price: 65 DM
Today: Shimano MTB drivetrain 2024
The latest development stage of the Shimano Deore XT rear derailleur looks mysteriously like a spy object from the secret "Area 51". The M8100 was introduced in 2021 with its Shadow RD+ technology and is still the benchmark today. ShadowRD+ technology reduces the preload in the rear derailleur, buffers the shifting process with a shock absorber and makes shifting quieter than ever before. The Hyperglide+ features provide support. They allow the chain to move smoothly, even under load. Larger pulleys (13 teeth) increase efficiency. The XT rear derailleur has been optimised for a 12-speed drivetrain with a large gear range. By the way: The latest version of the XT rear derailleur also works according to the inclined parallelogram principle. This means that the swing path of the shifting swingarm not only runs inwards, but also downwards. This corresponds to the climbing movement of the chain. This principle was invented by competitor Suntour in 1984.
Features
Stylised: The Shimano product designers seem to have put the rear derailleur through the wind tunnel - the Japanese call their technology ShadowRD+. They are designed to make gear changes quieter than ever before -- the latest model of the XT rear derailleur also works according to the inclined parallelogram principle. This has proven its worth since 1984 -- "Bigger is better": The diameter of the pulleys has been increased, which boosts efficiency.
- Type designation: RD-M8100
- Year of publication: 2021
- Material: Aluminium
- Gears: 12
- Weight: 284 grammes
- Price: 134,95 €
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Dimitri Lehner
Editor
