Guide 04
Alfine hub & shifter
Medium
Particular, not hard
Line up the yellow marks
The gearbox of the whole bike. Getting it shifting is less about force and more
about one fussy alignment — once the marks line up, it just works.
ELI5
Inside the hub is a little planetary gearbox. A cable from the shifter rotates a part on the axle
that selects the gear. There’s no derailleur, no indexing tension drama on a cage — just “pull
cable this far = this gear,” which the shifter handles for you.
The pieces
| Part | Role |
|---|
| Alfine hub (SG‑S7001, 8 or 11‑sp, black) | The gearbox. Laced into your
rear wheel. |
| Cassette joint / shifting unit | Clips onto the right‑hand axle end;
the cable connects here. This is the bit you align. |
| Shifter (SL‑S7000 trigger, or a drop‑bar solution) | Picks the gear.
Match it to the hub’s speed count. |
| Cable + housing | Connects shifter → cassette joint. |
How it goes
- Build the hub into the wheel and fit it to the (tensioned, chainline‑set) rear end — see
Chainline & tension.
- Fit the shifter and run cable + housing along the frame to the rear.
- Clip on the cassette joint and connect the cable.
- Set the gear to the alignment gear (typically 4 on an 8‑sp / 6 on an 11‑sp), then
adjust the barrel so the marks meet.
The fussy bit: line up the yellow marks
The cassette joint has two yellow lines (or yellow dots/arrows) that must sit exactly
on top of each other in the set‑up gear. If shifting is vague or skips, 9 times out of 10 it’s
these marks slightly off — turn the cable barrel adjuster until they align perfectly. That’s the
whole adjustment. (Refs: Shimano dealer manual for SG‑S7001.)
Tools
Cable cutter (clean housing/cable ends matter) · small spanner/allen for the cable pinch ·
that’s about it.
Still open in the build
8‑sp vs 11‑sp is undecided (your fewer‑gears preference points at the 8). The shifter and
a couple of small parts depend on that choice — settle the hub first. The non‑turn washers
(5R/5L) live with this job too; details in the chainline guide.