How to replace the indicator chain on the SRAM 3×7 hub

The small chain leading into the three-speed hub broke. (This refers to the SRAM 3×7 three-speed hub, formerly the SACHS 3×7 hub.)

This tiny chain is called the indicator chain. It runs into the hub and is pulled by the cable attached to the shifter. There are two pieces: the indicator chain itself, and the black plastic cable anchor that binds the chain to the cable.

The chain does come under a certain degree of stress and may need to be replaced from time to time. If it breaks, read on.

1. Remove the broken piece of indicator chain in the cable anchor by pressing the metal tab on the anchor and pulling out the stub of chain.
2. Pedal forward a full revolution or so, so that the hub is shifted into high gear by spring tension.
3. Lay the bike on its left side, chain side up.
4. Grab the stub of the indicator chain in the axle end with your fingers, or gently with pliers if it is too short. Turn the chain counter-clockwise like a bolt and it will unscrew easily.

   Tip: Remove the right side axle nut to expose more of the broken chain, if needed.

5. To reinstall, drop the end of the indicator chain with the smooth shaft and small threads into the axle hole until it stops. Turn the chain gently clockwise, like a bolt, until you feel it stop. Do not tighten. Just turn the chain until you feel it stop and then back off one-quarter turn.

   Tip: You will find the indicator chain easier to install with the axle nut on and tightened down. Dangle the chain into the locknut hole.

6. Reconnect cable anchor and adjust as outlined in “To reinstall the rear wheel” (see related articles, below).
7. Call Bike Friday to order another indicator chain for future adventures, or select it from the on-line catalog using the button below.

• Bike Friday’s 3×7 hub care and instructions [pdf]
• SRAM 3×7 wheel installation and removal instructions [pdf]
• SRAM 3×7 component schematic [gif]