Adjusting the Jab Standard Clutch

Remove the Jab derailleur from the bike. There is no need to break the chain. You can remove the upper chain pulley and lower cage spacer, and the chain will come out of the derailleur.

Clean all dirt off the clutch cover and surrounding area. Do not allow dirt to get inside the clutch housing or it will prevent the clutch from operating smoothly.

Insert a knife under the clutch housing were the M3 screw was. 

Pry the clutch cover up and remove it. Wipe off dirt.

Remove the M5 screw using a T25 torx driver.

Remove the M5 serrated washer, flat washer, and washer with square hole.

Note the order for re-assembly later.

The stack of shims will now be accessible. Each Jab clutch is tuned on the assembly line at Madrone, so not every Jab has the same number of shims when it is new.

Adjusting the Clutch

The Standard Clutch uses 0.1mm shims. 

To make the clutch have more friction: Add 1 shim at a time, re-assemble the washers and screw, then check the friction.

To make the clutch have less friction: Remove 1 shim at a time, re-assemble the washers and screw, then check the friction.

Adjustment Tips

The purpose of the clutch is to reduce chain vibration. This reduces the chance of dropping the chain from the chainring, and reduces chain slapping noises on the frame.

The standard clutch applies friction in both directions when the cage is moving.

Sweet Spot: The standard clutch works best when it has just enough (but not too much) friction in both directions to reduce chain vibration.

Remove shims to reduce friction. You can even set the clutch to have no friction if desired. This will give the cage maximum freedom to move. But depending on how rough the terrain is, it may move too freely.

Add shims to increase friction. But take care to not add too many shims. This will prevent the cage from being able to return fast, which will allow more chain vibration. The cage should return quickly and strongly to keep the chain as calm as possible.

When in doubt, adjust the clutch for less friction. The clutch friction works in both directions (kind of like suspension which has both compression and rebound damping), and you do not want too much restriction or the cage will no move freely enough to keep the chain calm.

After you get the desired clutch friction, remove the M5 screw with a T25 driver. Ensure the male and female threads are free of grease. Apply removable threadlocking compound to the threads, and re-install it.

Torque specifications are here.

Make sure all parts are coated with grease. This will prevent contamination and corrosion.

Make sure the walls of the housing are coated with grease. This will make sure the o-ring seal on the cover keeps water and grit out of the clutch.

Make sure the o-ring is clean and seated in the clutch housing grooves as shown. There may 1 or 2 corners where the o-ring stretches across, but that is OK.

Locate the D shaped slot in the clutch housing.

Locate the D shaped protrusion in the clutch cover.

First, insert the clutch cover D shaped protrusion into the D shaped slot.

Then, rotate the clutch cover down, taking care not to pinch or tear the o-ring. Snap the cover all the way down.

Apply removable threadlocking compound to the M3 flat head screw and install it. Take care not to over-tighten the screw. 

Torque specifications are here.

Clean off all excess grease from the derailleur, and then re-install it.

Installation and adjustment instructions are here.

Done!