Deal With a Broken Derailleur Cable
The issue: You’re struggling up a climb when you hear a snap and find you suddenly can’t shift to an easier gear. The rear derailleur cable gave way and you’re miles from the car.
Option #1: Good luck — you’ll effectively be riding a singlespeed to get home. Get off your bike and tweak the high limit screw until the derailleur is lined up with the right cog for the terrain.
If the front derailleur fails, tighten the low adjustment screw so it stays in the right position.
Option #2: (Which only works on bikes with cable stops) can sometimes gain you an easier gear. You’re still going to be one-speeding it for the rest of the ride, though. This option will work on either front or rear derailleurs, but the explanation that follows is in the context of the rear derailleur.
First, take your broken derailleur cable out of the shifter. Clean the broken and frayed end of the cable—often you can simply re-twist the cable into some semblance of cleanliness.
Take the other end of the broken cable, (presumably it’s still attached to the derailleur), and discard it in your pocket (littering makes kittens cry). Keep the cable housing. Now find the cable stop closest to the derailleur, usually on the seatstay or chainstay for a rear derailleur.
Thread the short, cleaned-up piece of cable through this cable stop and into the cable housing that’s (hopefully) still there. Pull it all the way through until the cable end that was inside the shifter sits snug against the cable stop. You should now have a clean-ish piece of cable to attach to the derailleur.
With your hand, manually push the derailleur to whatever gear you want to be in for the rest of the ride. While holding the derailleur in place, attach the cable to the derailleur in the normal manner. (This procedure is easiest with three hands, so hopefully you brought a friend.) If your derailleur has a barrel adjuster, use that to dial in the derailleur so it runs smoothly.
If your derailleur doesn’t have a barrel adjuster, it may take a bit of guesswork to get the derailleur properly centered over the cog.
These quick fixes will allow you to limp home, probably with some difficulty, depending on the trails. Derailleur cables age quickly and can snap unexpectedly, so it’s important to check for thin or worn spots. Replace cables frequently and solder or cap the ends to prevent fraying.
Also, and this may be obvious, a 26″ tube will work just fine on a 29″ wheel to get you home. Don’t walk your bike just because you are the only one of your friends who rides wagon wheels.
Yup, and the reverse is true as well – you can cram a 29″ tube into a 26″ tire.
Here is one:
Cut tire casing use a 1 dollar bill to boot the inside casing between the cut and the tube.
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