Shimano derailleur adjustment

There is no difficulty in mounting the Shimano derailleurs. On the other hand, there are a few small gestures to know to settle them precisely!

The tools

To mount and adjust Shimano derailleurs you will need a 2 mm Allen key, a 4 mm and a 5 mm Allen key. It will also be necessary to add the allen wrench that tightens to screw the derailleur hanger and a Phillips screwdriver for the races of the derailers. A torque wrench is also added to tighten the torque.

Pictures © Frédéric Iehl

With these three Allen keys you are ready for assembly.
The cruciform screwdriver will be used for the race of the derailers.
The torque wrench will be used to finish the tightening.

Time and difficulty

It takes one hour of work to set up and adjust the Shimano derailleurs. It’s not that complex, except for the front derailleur. A small gap and the ascents and descents of plateaus will be less frank.

Stage 1

We start by checking the tightening of the rear leg. It is visually controlled that it is not twisted.

Stage 2

We do the same for the front derailleur. Little chance here that she will twist.

Stage 3

The front derailleur is then positioned so as to adjust it in height. It must be slightly tight.Shimano derailleur adjustment

Stage 4

We start by positioning the derailleur in height. The fork must pass between 1 and 3 mm above the teeth.

Stage 5

Now we will orient the front derailleur so that its outer face is almost parallel to the teeth of the large plateau. The rear end of the derailleur can be shifted from 0.5 to 1 mm inwards.

Stage 6

The front derailleur is then tightened permanently.

Stage 7

We place a 5 mm allen wrench like this along the teeth of the big chainring and look at the gap with the fork.

Stage 8

We then play on this screw to glue (green) the fork or take it off (orange).

Stage 9

We start by greasing the fixing hanger.

Stage 10

We tighten the derailleur thoroughly on the hanger.

Stage 11

We avoid crushing this screw on the hanger.

Stage 12

We then make sure that the derailleur rotates freely on the paw.

Stage 13

There are 3 screws on the back of the derailleur. The A is for the running of the small pinion, the B for the running of the large pinion and the C to manage the gap between the rollers and the pinions.

Stage 14

Small chainring – bigger sprocket, we make sure that the derailleur does not touch the spokes. We then act on the B screw.

Stage 15

Large tray-small pinion, we make sure that the chain runs without noise and does not rub on the frame. We then act on the A screw.

Stage 16

The sprocket train must also be as close as possible to the pinions. Here we will reduce the distance a little.

Stage 17

We modulate the gap with the C screw. When we tighten (green) we move away, when we unscrew (orange) we bring…

Stage 18

On the front derailleur, the A screw is used for the race of the small plateau, the B screw for the race of the large plateau.

Stage 19

We put on a small large gable tray and look at how it goes.

Stage 20

We screw the A screw to bring the fork closer together, we unscrew it to keep it away. It must brush against the chain but without touching it.

Stage 21

We put the chain on the large tray and the small gable. We look at where the fork goes. Here too, it must brush against the chain without touching it.