Procedure

Verify hanger is straight first

(3.16). All other steps are wasted if it's bent.

Disconnect the shift cable

at the pinch bolt.

Set the high limit (H screw):

- Manually move the derailleur so the upper jockey wheel sits **directly under the smallest cog** when viewed from behind. - Adjust the H screw until this alignment is correct. Look down the chain line — upper pulley should be in plane with the smallest cog.

Set the low limit (L screw):

- Push the derailleur inward (toward the spokes) by hand or pull the cable. - Adjust the L screw so the upper jockey wheel sits **directly under the largest cog**, but the derailleur cage cannot move further inward and contact the spokes.

Set the B-tension screw:

- Shift the chain to the largest cog (or hold the derailleur there manually). - Set the gap between the upper jockey wheel and the largest cog to the derailleur manufacturer's specification. Some Shimano road/older MTB setups are commonly around **5–6 mm**, while many modern wide-range derailleurs require a setup gauge or a larger specified gap. - Turn the B-screw clockwise to increase the gap, counter-clockwise to decrease.

Reconnect the cable:

- Ensure the shifter is in its highest position (smallest cog). - Turn the barrel adjuster on the derailleur (or shifter) all the way in, then back out 1 turn — this gives you adjustment range in both directions. - Pull the cable taut through the pinch bolt; tighten to spec (4–5 Nm).

Index the gears:

- Shift the lever one click toward a larger cog. - The chain should hop cleanly to the next cog. - If it hesitates or fails to shift up: **add tension** (turn barrel adjuster counter-clockwise, 1/4 turn at a time). - If it overshoots or skips two cogs: **reduce tension** (turn barrel adjuster clockwise). - Work through every cog in both directions, fine-tuning until shifts are crisp throughout. ---

Procedure #

Verify hanger is straight first (3.16). All other steps are wasted if it’s bent.
Disconnect the shift cable at the pinch bolt.
Set the high limit (H screw):
- Manually move the derailleur so the upper jockey wheel sits directly under the smallest cog when viewed from behind.
- Adjust the H screw until this alignment is correct. Look down the chain line — upper pulley should be in plane with the smallest cog.
Set the low limit (L screw):
- Push the derailleur inward (toward the spokes) by hand or pull the cable.
- Adjust the L screw so the upper jockey wheel sits directly under the largest cog, but the derailleur cage cannot move further inward and contact the spokes.
Set the B-tension screw:
- Shift the chain to the largest cog (or hold the derailleur there manually).
- Set the gap between the upper jockey wheel and the largest cog to the derailleur manufacturer’s specification. Some Shimano road/older MTB setups are commonly around 5–6 mm, while many modern wide-range derailleurs require a setup gauge or a larger specified gap.
- Turn the B-screw clockwise to increase the gap, counter-clockwise to decrease.
Reconnect the cable:
- Ensure the shifter is in its highest position (smallest cog).
- Turn the barrel adjuster on the derailleur (or shifter) all the way in, then back out 1 turn — this gives you adjustment range in both directions.
- Pull the cable taut through the pinch bolt; tighten to spec (4–5 Nm).
Index the gears:
- Shift the lever one click toward a larger cog.
- The chain should hop cleanly to the next cog.
- If it hesitates or fails to shift up: add tension (turn barrel adjuster counter-clockwise, 1/4 turn at a time).
- If it overshoots or skips two cogs: reduce tension (turn barrel adjuster clockwise).
- Work through every cog in both directions, fine-tuning until shifts are crisp throughout.

Rear Derailleur Setup (Mechanical)

Tools