Installing the Jab Mounting Bolt
1. Preparation
Safety
- Safety glasses
- Recommended: Nitrile gloves
Tools
- Metric hex keys (individual, not from a multi-tool)
- Pick
- Small flat blade screwdriver
Torque and Threadlocker
All fasteners require threadlocker and proper torque.
Torque and threadlocker specs are on this page.
Parts
-
Mounting bolt kit (there are 3 options):
- Standard (short bolt, M10 shim, o-ring)
- Stiffener for UDH (long bolt, stiffener plate, M10 shim, o-ring)
- Stiffener for T-Type (long bolt, T stiffener plate, M10 shim, o-ring)
Supplies
- Threadlocker (such as blue Loctite 242)
- Marine grease
- Citrus degreaser
- Rags
2. Remove Old Mounting Bolt
Remove Derailleur
Remove the Jab derailleur from the bike.
No need to break the chain. Remove the upper chain pulley and lower cage spacer, and the chain will come out of the derailleur.
Clean all dirt off the area around the cable pulley and bracket.
Prepare Derailleur
Lock the cage with a tool.
Back the B screw out so the tip is flush with the surface, as shown.
Remove B Screw Plate
Use a pick to remove the o-ring from the outer edge of the B screw plate.
Take care not to damage the o-ring.
Wiggle the B screw plate back and forth while pulling it, to get it over the hidden o-ring and off the mounting bolt.
Remove Mounting Bolt Parts
Remove the o-ring from the mounting bolt.
Pinch it with your fingers to get a pick underneath it.
Remove all the remaining mounting bolt parts.
Depending on which mounting bolt kit was in your derailleur, the parts may look different from this photo. This photo shows the standard mounting kit.
More details on the mounting options are on this page.
Compare Mounting Kits
This photo compares the stiffener plate kit to the standard mounting bolt kit.
Note the location of the M10 shim in each.
A stiffener plate needs the long bolt. The standard mounting bolt is shorter.
3. Install Bolt & Springs
Install Mounting Bolt
Grease this surface on the derailleur.
Install the bolt, the M10 shim, and the stiffener plate (if used).
Note: The M10 shim contacts the body of the derailleur, regardless of the type of mount.
Install Conical Disc Springs
Important:
Locate the 2 M10 conical disc springs. The orientation of the springs is critical for proper function.
When installed, they should face each other as shown, creating a void between them, like two crash cymbals.
Apply grease to this surface of the derailleur.
Install the first M10 conical disc spring and press it down.
Apply grease to the first M10 conical disc spring.
Install the second M10 conical disc spring and press it down.
Apply grease to the second M10 conical disc spring.
4. Install B Screw Plate
Install Large O-Ring & Plate
Install the larger of the 2 o-rings on the B screw plate, as shown.
Cross it over the lip so it stays in place (see the 2nd photo).
Install the B screw plate.
Install Small O-Ring
Install the smaller o-ring.
Use a new o-ring, not the one you removed. A damaged o-ring won't hold the B screw plate in place well.
Start the o-ring by placing it on the threads.
Then pinch the o-ring to get a small flat blade screwdriver (or pick) under it.
Walk the o-ring down the threads, past the first groove next to the threads, and into the second groove, which is hard to see.
Seat the o-ring fully in the second of the 2 grooves. Don't seat it in the groove next to the threads.
The B screw plate will have some wiggle, which is normal. It will become tighter when the derailleur is installed.
Seat Large O-Ring
Seat the larger o-ring in its proper location by moving it over the outer lip of the B screw plate.
Set B Screw
Thread the B screw in so it keeps the B screw plate within a limited rotation range.
The B screw will protrude about 3–6mm.
Reinstall Derailleur
Clean off excess grease.
Reinstall the derailleur.
Installation and adjustment instructions are here.
Done!
