Shimano Alfine is a product series of bicycle components marketed by Shimano, a Japanese manufacturer of cycling components. The series is oriented toward urban, commuting, trekking, and comfort cycling rather than competitive road or mountain racing. It is best known for internally geared hubs, but the group also includes hydraulic disc brakes and levers, shift levers, chain tensioners, dynamo hubs, cranksets, and complete wheels.
Product concept
Alfine hubs are internally geared hubs (also called epicyclic or planetary hubs), in which the gear-changing mechanism is enclosed within the rear wheel hub shell rather than being exposed as a derailleur and cassette. This arrangement allows gear changes while stationary, requires less maintenance, keeps the drivetrain cleaner, and permits the use of a fully enclosed chaincase or a belt drive. The trade-offs generally cited are greater weight, higher cost, and somewhat lower mechanical efficiency than a well-maintained derailleur system.
Models
Alfine 8-speed (Alfine 500 group)
The Alfine 500 group was introduced at the Eurobike trade fair in 2006 and included the SG-S500 hub. Its internal mechanical design was based on the Shimano Nexus Inter-8: two stepped planetary gear trains with fifth gear as a 1:1 direct drive. It provides eight speeds with an overall gear range of approximately 307%. Intervals between gears are uneven (roughly 22%, 16%, 14%, 18%, 22%, 16%, and 14%). These hubs are grease-lubricated and feature a hub shell with splines for mounting a Center Lock disc brake rotor. A later SG-S505 variant (2013) added Di2 electronic shifting. The current equivalent models are designated SG-S7001-8 (mechanical) and SG-S7051-8 (Di2), the latter approved for both e-bike and non-e-bike use.
| Gear | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|---|---|---|---|---|---|---|---|---|
| Ratio | 0.527 | 0.644 | 0.748 | 0.851 | 1.000 | 1.223 | 1.419 | 1.615 |
Alfine 11-speed (Alfine 700 group)
The Alfine 700, with the SG-S700 hub, has been manufactured since 2010. It offers 11 speeds using three stepped planetary gear trains running in a sealed oil bath. The overall gear range is approximately 408–409%, with a first-to-second step of about 29% and roughly 13–14% steps thereafter. Unlike the 8-speed, it has no 1:1 direct-drive gear. Claimed weight at introduction was approximately 1,600 g without auxiliary components (bolts, actuator, sprocket, cable, shifter). It is operated by a ratcheting trigger shifter with two-way release. A Di2 electronic-shifting version, the SG-S705, followed in 2013; current equivalents include SG-S7001-11 (mechanical) and SG-S7051-11 (Di2). The Di2 version requires a motor unit, a battery, and electronic shifters, which are not interchangeable with the mechanically shifted model.
| Gear | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Ratio | 0.527 | 0.681 | 0.770 | 0.878 | 0.995 | 1.134 | 1.292 | 1.462 | 1.667 | 1.888 | 2.153 |
Independent technical analysis describes the 11-speed hub as functionally a two-speed stage (reduction or direct) driving a six-speed stage, which itself comprises a three-speed stage driving a final two-speed stage. Gear selection is accomplished through a combination of sliding and locking clutches and spring-preloaded roller clutches.
Characteristics and known issues
Because the 11-speed hub is oil-lubricated and fitted with an oil port, Shimano specifies a periodic oil-change schedule and supplies an oil-change kit. Documented issues reported in technical literature and user communities include oil seepage from the large right-hand bearing seal, sensitivity of the cable-operated shift mechanism to build tolerances and cable adjustment, and occasional reports of gear skipping. Some analyses also note that gears using a single gear train (such as 1, 7, 8, and 9) tend to be more efficient than those combining multiple trains. Maintenance guidance generally recommends releasing pedal force during shifts, as with other internal-gear hubs.
Context
Internally geared hubs such as Alfine are frequently compared with the Shimano Nexus line (a more utilitarian, generally lower-cost series) and with the Rohloff Speedhub (a high-end 14-speed internal hub). Shimano positions Alfine above Nexus within its product hierarchy, as a "premium-level" component group for urban and lifestyle bicycles.
