Garage Files: How To Keep Your Derailleur & Cables Finely Tuned
the shifter cable housing. From there, we will look at how to adjust the mechanical rear derailleur on a very common SRAM 1×12 drivetrain available on the market today. As we go through these steps, we will also explore some similarities and differences of other brands’ derailleur systems. Now, let’s shift over and grab a wrench.
Measuring and Cutting
To determine the housing length, use the least amount of housing necessary to get the job done while still having enough for a full range of motion at the handlebars and all other moving parts on the bike, like the rear linkage.
Step 1: Shift the rear derailleur to its neutral position (smallest cog). Start by checking the current housing length at the bars and derailleur. If the housing snags or is limiting the rotation, it needs to be longer. There are some cases where the housing may be too long or need to be cleaned up.
Step 2: Cut the exposed rear-derailleur cable between the cable anchor bolt and cable guide. For now, leave the remaining cable under the anchor bolt. You’ll see why shortly.
Step 3: Now, remove the cable from the shift lever. Depending on the brand of shifter, this step might require a slightly different technique. Before you go pulling the housing out, double-check how the cables are routed. If they are routed inside the frame, we highly recommend looking into an internal-routing kit to replace the housing efficiently (as we have done). To save money, you can also…