Advanced Hub Gears
Advanced hub gears offer a higher numbers of gears by using multiple epicyclic gears driven by each other. Their ratios are chosen to give more evenly spaced gears and a larger total gear range. The operating principle of such units is the same as with less advanced systems, with a trigger or twist shifter with sequential shifting.
- The 12-speed Sachs Elan was the first hub gear with 10 or more speeds in the market (1995-1999). Unfortunately, it was considered heavy and plagued with quality issues, hence discontinued after a few years.
- The 14-speed Rohloff Speedhub hub gear, introduced in 1998, has a range exceeding 5 to 1, and are now more comparable to 24-speed or 27-speed derailleur systems, since the latter have three overlapping ranges often with only about 14 distinct gears. As there is no overlap, the hub gear is easier to operate, and an oil bath creates a comparable mechanical efficiency to derailleur gears.
- The 11-speed Shimano Alfine 700 hub gear, introduced in 2010, has a gear range exceeding 4 to 1, comparable to 20-speed derailleur drive-trains, and internals running in an oil bath, for greater mechanical efficiency.
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