Sachs und SRAM Nabenschaltungen: Unterschied zwischen den Versionen

Starting in the 1980s, Sachs expanded its line of internal-gear hubs to include hybrid gearing systems -- first the Orbit, a two-speed hub with proprietary sprockets, then the 3 x 7 followed by the 3 x 8, and 3 x 9 DualDrive 2 systems and the 3 x 10 DualDrive 3 using a three-speed internal-gear hub and Shimano-compatible cassettes. These newer hubs are especially useful on small-wheel bicycles, because the step-up top gear avoids the need for an extra-large chainwheel. Sachs also introduced 5-speed and 7-speed models and the Elan, a very large and heavy 12-speed hub which was a marketing failure. In the 2007 model year, SRAM introduced the i-Motion 9-speed hub. It was withdrawn, and as of 2014, SRAM offered an 8-speed hub, the G8, and a different 9-speed, the G9, but they also were withdrawn. In 2013, manufacture of SRAM internal-gear hubs was moved from Germany to Taiwan, though engineering was still in Schweinfurt, Germany and in 2017, as described, the line of internal-gear hubs was discontinued..

SRAM internal-gear hubs are notable for the fine quality of machining of their internal parts. Gear-tooth surfaces and bearing races are smooth. The SRAM 3-speed, in particular, has higher measured drive efficiency than other 3-speed hubs, possibly due to the quality of the machining.

Many Sachs/SRAM hubs have coaster brakes, and these hubs must be lubricated with grease -- often two types of grease: one for the gear mechanism, so it doesn't make the pawls stick; another for the brake parts, to resist heat buildup.

Also see the more general advice on this site about lubricating internal-gear hubs, and on types of oil.

My favorite Sachs/SRAM hubs are discontinued models -- the 3 x 7 DualDrive, discontinued in 2000, and the S7 7-speed with drum brake, discontinued in 2010.

The G8 and G9 look promising for urban use, but I don't have hands-on experience with them.

Aaron's Bicycle Repair in Seattle, Washington, USA specializes in repair of internal-gear hubs and stocks parts for SRAM hubs including discontinued models.

My intention here is to provide the best information I can on rebuilding Sachs/SRAM hubs.

Andree Schote's site also has information (in German) on older Fichtel & Sachs hubs.

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