Shimano Alfine DI2 SG S7051 11 SPD Intertnal Centerlock Rear Hub
The Shimano Alfine Di2 SG-S7051-11 is the Alfine 11 with electronic shifting: the same eleven gears in an oil bath with a 409% range, a centerlock disc mount, chain or belt compatibility and 135mm spacing, shifted by a motor in the hub driven by a Di2 shifter and battery rather than a cable. Shifts are exact every time with no cable to stretch or adjust, and the hub can shift at a standstill. It is the hub we build for premium commuter, touring and belt-drive bikes. This page covers the Shimano Alfine DI2 SG S7051 11 SPD Intertnal Centerlock Rear Hub.
The Alfine Di2 11 comes from us only as a finished wheel: pick the rim, spokes and nipples, and we lace, tension and true it by hand in Georgia before it ships.
Design and construction
An internal-gear hub is a planetary gearbox inside the hub shell: a set of sun and planet gears that the shifter engages in different combinations to give eleven ratios from a single sprocket. The Alfine 11 runs its gears in an oil bath rather than grease, which makes it smoother and longer-lived than the 8-speed and needs an oil change every couple of years. Shifting is by a single cable through Shimano's Rapidfire trigger or a twist shifter, and the hub can shift at a standstill, which is a real advantage in traffic. It takes a single sprocket for chain or a Gates belt sprocket, has a centerlock disc mount, and is drilled for J-bend spokes in 32 and 36 hole.
How it rides
An Alfine Di2 11 bike shifts with a click and a whir, exactly the same on the first day and the thousandth, and there is no cable to adjust ever. With a belt drive and disc brakes it is about as maintenance-free as a bicycle gets. The 409% range covers real hills. For a cable-shifted Alfine the SG-S7001-11 is the same hub at a lower price.
Specifications
| Position | Rear |
|---|---|
| Axle options | Bolt On 10x135mm Rear |
| Driver bodies | Internal Single Speed Spline |
| Drillings | 32h, 36h |
| Spoke head | J-bend |
| Brake | centerlock disc |
| Left flange diameter | 92.6 mm |
| Right flange diameter | 92.6 mm |
| Left center-to-flange | 31.8 mm |
| Right center-to-flange | 25.5 mm |
| Spoke hole diameter | 2.6 mm |
| Weight | 1665g |
| Material | Aluminum |
| Finishes | black, silver |
About this listing
What sets this listing apart from the other Alfine Di2 11 versions: centerlock rotor mount, Bolt On 10x135mm, 32h, 36h drilling, about 1665g, in black, silver. Pick the one that matches your frame and rotor and the rest of the hub is identical.
Centerlock is the lighter, quicker rotor mount: a splined rotor drops onto the hub and a single lockring holds it, so a rotor swap takes a minute with a lockring tool and there are no six small bolts to torque or lose. Shimano and most current road and gravel rotors are centerlock; 6-bolt rotors fit with an adapter.
Sizes, fit and compatibility
The Shimano Alfine DI2 SG S7051 11 SPD Intertnal Centerlock Rear Hub comes in the drillings listed on this page in 135mm quick-release spacing with a centerlock rotor mount; it needs a frame that can tension the chain or belt and a Di2 shifter, battery and wiring, which we can supply. J-bend spokes in any gauge; we build most Alfine Di2 wheels with DT Champion or Competition or Sapim Race and Strong spokes and brass nipples.
It pairs naturally with the Velocity Dyad, Atlas and Cliffhanger, Mavic A319, HED Belgium G and Velo Orange Voyager rims. Pick commuter or touring as your bike type in the configurator and it recommends a spoke count and lacing pattern.
Build a wheel around it
Offered for road rim brake, gravel and road disc, track and road single-speed, touring, tandem and e-bike, mountain bike, MTB single-speed and fat bike builds in our Custom Wheel Program. Start with the Shimano Alfine Di2 Sg S7051 11 SPD Intertnal Centerlock Rear Hub and the configurator pins it for you, then checks each choice you make against it.
Testing, standards and warranty at Shimano
Shimano publishes no load, fatigue, or salt-spray figures for its hubs. Its US warranty states that most bicycle products are warranted free from defects in material and workmanship for two years from original purchase, and that DURA-ACE and XTR components and wheels are covered for three years, for the original owner with proof of purchase. Competition or commercial use, improper assembly or repair, finish deterioration, labor, and normal wear are excluded; bearings, corrosion, dust seals and spokes are listed as wear parts.
stated engagement is 10 degrees (TC600), 15 degrees (TC500/QC500) and 22.5 degrees (QC400/QC300), with interchangeable Micro Spline and HG freehub bodies. The warranty lists free hubs, driver bodies and pawls as wear parts not covered.
Certifications
- Warranty: 2 years / 3 years — Most bicycle products two years from original purchase; DURA-ACE and XTR components and wheels three years; original owner, proof of purchase; wear parts excluded (bearings, dust seals, free hubs, driver bodies, pawls, spokes) (source)
- ISO 9001 and ISO 14001 (Malaysian wheel/hub factory) — Reported by Bicycle Retailer, 19 Dec 2007: factory producing wheels incl. Dura-Ace, hubs, cranks, pedals is “ISO 9001 and 14001” compliant; 89,000 sq m, 2,087 employees (source)
Sources on Shimano's site:
- SHIMANO Warranty Policy | Ride Shimano US
- Is Shimano abandoning cup and cone hubs? - road.cc
- Shimano says RIP to cup-and-cone bearings with new hubs - BikeRadar
- Shimano's new Dura-Ace wheels double down on cup-and-cone hubs - BikeRadar
- Shimano Dura-Ace WH-R9370 C50 first look - BikeRadar
Shimano publishes those results; ProWheelBuilder builds the hub into a wheel and does not test it in a lab.
Building it at ProWheelBuilder
Shimano makes the Alfine Di2 11; ProWheelBuilder is an independent custom wheel builder in Georgia and not the manufacturer. We measure the rim before we cut a spoke, bring the wheel up in three or four rounds with a gauge, stress-relieve it between rounds and true it last, then tape it and fit a valve if you want it tubeless.
Only compatible hubs and spokes appear in the configurator, impossible combinations are struck through rather than hidden, and the price is live.
Warranty
Shimano's warranty. Shimano covers its bicycle components for two years from original purchase, with three years on DURA-ACE and XTR and one year on wheels, footwear and soft goods. Shimano's obligation is to repair or replace at its option, against the original dated receipt.
ProWheelBuilder. Lace this into a wheel here and the finished wheel gets our own one-year warranty as well as the maker's. For twelve months we replace broken spokes however they broke, and the work on the wheel is on us - truing, re-tensioning, a rebuild where it is needed. If the rim or hub is covered by its manufacturer we put the claim in and chase it; if it is not, we supply an eligible replacement rim or hub at 25% off the current retail price. Carriage both ways is the customer's, and this does not cover wheels built from parts you send in.
Full terms are on our Policies & Warranty page.
Alfine DI2 SG S7051 11 SPD Intertnal Centerlock Rear Hub questions
Will my rotors fit this hub?
This is the centerlock version, so a splined centerlock rotor drops on and a lockring holds it - one tool, no six bolts to torque or lose. If your rotors are 6-bolt they will fit with a centerlock adapter, or take the 6-bolt version of the same hub, which is a separate listing.
What does the Alfine Di2 need besides the hub?
A Di2 shifter, a battery, the wiring and a junction box; we can supply and fit them.
Does the Alfine Di2 work with a belt drive?
Yes. It takes a Gates belt sprocket like the cable version.
How long does the Di2 battery last?
Weeks to months of commuting on a charge, depending on how much you shift; it charges from USB.
Alfine Di2 11 or cable Alfine 11?
Di2 for exact, adjustment-free shifting and shifting at a standstill with a button; cable for a lower price and no battery.
Which axle spacing does it fit?
Bolt On 10x135mm Rear. Measure between the inside faces of your dropouts if you are unsure, or text us.
Does it need special spokes?
No. It takes standard J-bend spokes, which the configurator offers in every gauge and finish we stock.
Not sure? Text or leave a voicemail on 470-253-0929 or email info@prowheelbuilder.com — you will be talking to the people who build the wheels.
