Shimano Alfine SG-S7051-8 Di2 8-Speed Internal Gear Hub — Centre Lock, 36H, 135x187mm, Black
ISGS70518AL
SKU code: SHM-ISGS70518AL
The Shimano Alfine SG-S7051-8 brings Di2 electronic shifting to an enclosed 8-speed internal gear hub, delivering smooth, precise gear changes without exposed derailleurs or cables. With a 307% gear range and compatibility with Shimano E-bike motor units, it suits urban commuters, tourers, and e-bike builds alike — all in a low-maintenance sealed package.
Highlights
- 307% total gear range across 8 speeds
- Shimano Di2 electronic shifting — precise actuation under load
- Approved for Shimano E-bike and non-E-bike use
- Centre Lock disc brake interface
- 36-hole lacing for strong, versatile wheel builds
- Includes rotor mount cover
- Sealed internal gear system — minimal maintenance, all-weather reliable
- Aluminium hub shell construction
Internal Gear Technology
The Alfine S7051-8 uses Shimano's Inter-8 planetary gear system housed in a sealed aluminium shell. The improved internal structure delivers higher shifting performance even under the elevated chain tension produced by E-bike motors, making it a natural fit for assisted commuter and cargo builds. All gear changes happen electronically via Di2, with no mechanical cables to stretch or corrode.
Disc Brake Integration
The hub features a Centre Lock rotor interface and includes a rotor mount cover. A built-in Power Modulator provides easy, progressive braking control. The 135mm over-locknut dimension (O.L.D.) suits standard rear dropout spacing on city, hybrid, and commuter frames.
Compatibility & Fit
- Over Locknut Dimension (O.L.D.): 135 mm
- Axle length: 187 mm
- Spoke holes: 36H
- Brake mount: Centre Lock (disc)
- Shifting: Shimano Di2 electronic (requires compatible Di2 junction and battery)
- E-bike compatible: Yes — approved for Shimano MU-UR500 / MU-UR510 motor units
- Spoke gauge: 13g (2.3 mm) or 14g (2.0 mm)
- Colour: Black
Shimano provides a manufacturer's warranty on this product against defects in materials and workmanship. Opening or disassembling the hub, or using non-approved lubricants, will void the warranty. For warranty support, return the item to Tune Cycles.
- 8-speed internal gear hub with 307% total gear range
- Shimano Di2 electronic shifting system
- Approved for Shimano E-bike and non-E-bike use
- Centre Lock disc brake interface with included rotor mount cover
- Built-in Power Modulator for smooth, progressive braking
- 36-hole flange for strong wheel builds
- O.L.D. 135 mm, axle length 187 mm
- Sealed aluminium hub shell — all-weather, low-maintenance
- Compatible with Shimano MU-UR500 / MU-UR510 motor units
- Black anodised finish
| Speeds | 8 |
| Gear Range | 307% |
| Shifting System | Shimano Di2 electronic |
| Brake Type | Centre Lock disc |
| Over Locknut Dimension (O.L.D.) | 135 mm |
| Axle Length | 187 mm |
| Spoke Holes | 36H |
| Pitch Circle Diameter | 92.6 mm |
| Flange Diameter | 104.3 mm |
| Flange Width | 3.2 mm (left & right) |
| Flange Distance | 57.3 mm |
| Offset | 3.15 mm |
| Supported Spoke Gauge | 13g (2.3 mm) / 14g (2.0 mm) |
| Hub Shell Material | Aluminium |
| Colour | Black |
| E-bike Approved | Yes (MU-UR500 / MU-UR510) |
| Includes | Rotor mount cover |
| SKU | SHM-ISGS70518AL |
| Barcode # | 4524667905370 |
| Brand | Shimano |
| Shipping Weight | 0.3000kg |
| Shipping Width | 0.220m |
| Shipping Height | 0.030m |
| Shipping Length | 0.220m |
| Shipping Cubic | 0.001000000m3 |
| Unit Of Measure | each |
