When it fucking snaps:
Ok, so I decided to replace it myself because the dudes at ye olde bike shoppe said that it wouldn’t be fixed before 7pm, which is too damn late for me! It’s actually super easy to replace bike gear cables. The hard part is making the adjustments so that your gears change smoothly, so I won’t be telling you anything about that.
First, get yourself a cable. This baby set me back $2.72. Ouch.
See those two prominent screws? You’ll want to unscrew them. Maybe you don’t have the same braking/gear system as I do, but for these Shimano‘s those screws are your gateway to the innards.
There. See the cable head? Snapped just as we expected to see.
The easy part: Feed the new cable through the guide holes. You really cannot miss. Don’t forget to guide the cable through the cable sheath as well.
Now guide the cable through the rest of the guide holes until you’re at the rear wheel. Again, it’s impossible to miss if you pay attention. Guide the cable through the sheath, attach it (you’ll need an Allen Key), and adjust as needed. It’s a good idea to flip your bike upside down at this point and test that you can actually shift gears while the wheels are spinning. You’ll determine just how much slack the cable needs this way. And that’s it! Now go put your bike away until next summer.