Which Parts to Replace
What are the most commonly replaced components?
Links and Super Shims
There are 2 common contributors to less than perfect shifting: play and deformation in the links and mounting bolt of the derailleur. These are common due to the high stresses in those areas. The derailleur assembly is like complex lever arm where the highest stresses occur nearest to the attachment point.
We find that most used or semi-functional (but not destroyed) derailleurs are brought back to full shifting performance with the Missing Links and Super Shims. This is because these products remove the excess play in these pivots. Furthermore, the Missing Links replace the stock links with straight, precise, durable links.
Cages
A bent cage is also a contributor to shifting issues, even though links are more important to address. If your cage is even slightly bent, it will need to be replaced. However, if you want to refurbish your stock cage (GX or X01), you can remove the parts and bend them back to straight if you have a flat reference surface. The XX1 cages are fiber reinforced plastic, and rarely bend, and therefore are rarely a contributor to shifting issues.
Pulleys
Worn pulley bearings and teeth can be a small contributor to shifting issues. New pulleys can be thought of as putting the “finishing touches” on shift performance to get it back to 100%.
Pivot Pins
Unless the pivot pins of the links are clearly bent, they rarely need to be replaced. However, if you do need them, the Madrone pins are an excellent replacement.
Battery Contacts
If your battery contacts are stuck down or don't make contact, we can fix that for you with our Professional Mail-In Rebuild Service. We remove the old pins and board, solder new pins to the wires, and then bond them into a 3D printed frame. They function as good as new and restore the electrical contact to the battery.

When is a derailleur not worth rebuilding?
SRAM Clutch
The SRAM clutches are not rebuild-able or adjustable. They are manufactured as a closed sub-assembly and molded into a plastic housing. Over time, they lose friction, leading to more chain noise and poor chain retention. If your SRAM clutch is not working, we recommend getting a new derailleur.
Clutch Housing
The plastic SRAM clutch housing should not be deformed or cracked. There are no spares for these parts.
However, there is a cosmetic cover on the clutch housing with the SRAM graphics on it. This part has no function, and is not required for a perfect shifting derailleur. More info on the cosmetic plastic cover here.
Servo Housings / Mounting Brackets
If the servo housings (or mounting bracket parts) are bent or damaged beyond repair, there is no straightforward way to bend them back into alignment, and there are no spare parts. These must be straight and functional for a derailleur rebuild to result in as-new shifting.
Servo
Other than the battery contacts, the servos are not repairable. Often the servo gears can get stripped internally from an impact to the derailleur. Tip: Never force the derailleur to move through the gears by hand, or you can damage the servo.
Battery Latch
If your plastic SRAM battery latch is broken or worn out, unfortunately we do not have a solution for this.