12 Step Derailleur Tuning

Want to learn how to adjust and fix your derailleurs? Here is the 12 step program as set forth by Jerzy "Smokey" Dymny of the Quadra Bike School.

1. Rear derailleur. Shift to high gear (small ring) and disconnect DR cable. (If DR has a reverse-rise spring the DR travels in opposite direction when released. In that case reverse these instructions for high and low cogs.)

2. Set high limit screw. Chain must travel smoothly on smallest cog but not go past it.

3. Check the complete cable path and reconnect rear derailleur cable.

4. To tune rear shifting, shift chain to middle chainring in front & tighten rear barrel adjuster until each shift click produces one clean downshift in the rear.

5. Adjust the low limit screw to let the chain reach large (low) cog but not shift past it. Check guide pulley spacing and adjust “B” screw to increase spacing if necessary.

6. Test up shifts. Turn barrel adjuster slightly in, if any shift is slow. Repeat till perfect.

7. Leave rear DR in low (large). Disconnect front cable. Adjust height of front derailleur 1–3mm above large ring.  Set front DR low limit screw. Tightening low limit screw pushes derailleur outward from frame.

8. Check complete cable path. Reconnect front cable.  Leave front DR in small ring. Test rear DR shifts up to second highest cog.

9. Shift front DR to middle ring. Test rear DR shifts through all gears.

10. Place Chain/String tool on smallest rear cog and largest chainring. Rotate front cage to match the cage engagement gap to the string angle.

11. Shift to the large ring. Set high limit screw. Test rear shifting to second lowest cog.

12. Check that front derailleur shifts through whole range & downshifts quickly.

© 2012, Quadra Bike School