46. How to Replace an Inner Shift Cable
Remove the old inner shift wire and install a new one.
Shift cable inner wires wear out over time. Other than obvious fraying, rust or visual wear, you can tell your cables are worn when your shifting starts to feel sluggish. If lubricating the housings or shift levers doesn’t help, they’ll likely need replacing.
For this job, you’ll need a replacement shift cable inner wire. Shift cable ends have a cylinder barrel shape as shown here. I recommend stainless steel cables if you’re riding regularly in a wet climate, as they won’t rust. You’ll need a good set of wire cutters, some bicycle specific cable cutters if you’ll be replacing the outer cable housing, and some triflow or light lubricant. You’ll need either a 9 or 10mm metric open end wrench or a 5 or 6mm hex key for the derailleur’s cable pinch bolt. You’ll also need to know how to adjust your front or rear derailleur, as explained in previous tutorials.
The first step is to relieve cable tension by shifting your derailleur so the chain is on the smallest sprocket on either your front or rear derailleur.
Carefully observe how your cable is presently routed from the shift lever to your derailleur. A misrouted cable can cause many problems. It may help to photograph each section of the cable from the shifter to the derailleur so you can use it for reference. Your derailleur may not look exactly like the one pictured here, but the concepts will be the same.
Now disconnect the cable at the derailleur’s pinch bolt. Notice how the cable is flattened where it was pinched. I like to cut the cable just before this part so it is easier to remove by sliding through the outer cable housings. I recommend replacing the outer cable housings at the same time. See the tutorial titled “How to Replace Cable Housings”.
Once you have nothing but the shift lever and the cable left, push the cable gently until you see the head poke out of the lever. Now you can pull it the rest of the way until it is completely removed. Depending on what type of shifters you have, reinserting the new cable can be tricky. I like to give the end of the cable a slight bend to help guide it through. If it meets resistance, try rotating the cable a little bit and gently pushing until it slides all the way through.
If your shifter has a barrel adjuster, turn it clockwise all the way and then back it off one full turn. Drop some light oil into your cable housings and make sure the outer housing’s cable ferrules are firmly in place before carefully sliding the new cable through the housing. If your derailleur has a barrel adjuster, tighten it all the way clockwise and then back it off one full turn. Then route your cable the same way it was before and thread the inner cable under the derailleur’s pinch bolt washer. Often there is a groove on the derailleur where the cable is meant to sit. Pull the cable tight and tighten the pinch bolt. The cable will flatten when tightened. Always tighten bolts to the manufacturer’s torque specifications. Adjust the derailleur as needed. See the related tutorials for tips on adjusting derailleurs.
Once installed and adjusted, cut the wire about 2 inches further along the cable. Your new cable should have come with a cable end that can be gently crimped on using wire cutters or pliers. This will prevent fraying.
So I've recently noticed that my rear dérailleur has almost completely lost its ability to shift the chain between sprockets (on a good day, it can move between two of the seven rear sprockets).
I think I've found the source of the problem in the shift mechanism:
In the photo, you can see the dérailleur cable enter a white plastic part (just below the "2"). You can also see some big metal wires emerging from the housing and meeting this white plastic part (just below the "1").
When the dérailleu... Read more >>
I was having issues with my bike chain slipping on the front derailleur mid ride and skipping gears on the rear when shifting. Did some reading determined that my derailleurs probably needed adjusting, most likely because as a relatively new bike the cables would have stretched. I had my housemate have a look (he has a little bit of bike knowledge) he twisted the H and L screws and the barrel adjuster to show me what they do (actually made the front derailleur worse) and left me to it.
Anyway I'm normally pretty good at fixing things so I followed instructions from the internet a... Read more >>
Can anyone tell me where to begin when resetting the position of the front derailer and shift cables on a cheep older Walmart bike? I was trying to fix the scrapping of the derailer and shifting problems but messed up and loosened the shift cable bolt and can't get anything back. I loose the large ring or the small during shifting so I need to start from scratch...but where?... Read more >>
I recently got a Trek Antelope 800, and the thumb shifter is broken. I have found a thumb shifter (Shimano Tourney SL-TX50) but I am not sure if it comes with the cables I need to install. Anyone know where I could get these cables?... Read more >>
I'm putting my plan together to fix up a Fuji Allegro, and I'm curious if I can tuck the cable housing for the brakes under the handlebar tape, or if it must be above. Not a deal breaker either way, just curious if it is a functional idea.... Read more >>
[attachment=4841]I have a non-branded carbon fiber TT bike (Cervelo P3) purchased on the internet. It looks very similar to the picture posted. The problem is once the shift cables are installed and adjusted the shifting only works a couple of times or less and then hangs up and the cable binds up somehow and the bike will not change gears. When you take the tension off, the cable will slide back and forth thru the housing without hanging up. Has anyone experienced this before? Is there a way to replace the internal housing? I think the frame is not hollow and has plates that the hou... Read more >>
So I bought a new Schwinn bike to replace my old one that got stolen, and on the first set of gears (the ones connected to the pedals) the cable wasn't taught enough to switch gears. So, I researched, and found that the cable had to be tighter. So I thightened it. Now it goes up to 3 from the first gear, but it won't go down to the 2nd gear. So I turned the dial to one, and it went to one. It won't go to the second gear even though the dial says it is. What should I adjust to fix this? I ride long distances, and up bridges, so this is kind of a big problem.... Read more >>
Can anyone tell me the difference between galvanised and stainless steel cables/wires? From what I have read online, stainless steel doesn't rust. I have bought some cables, so how do I check what material it is?
Thank you... Read more >>
Hi! Newcomer here.
I am the proud owner of a KTM Ultra Fun So far it has been nothing but joy, until recently the right-hand gear-shift cable decided to burst and detach from the gear-shift lever (Shimano ST M410) in the middle of a ride, part of the cable remaining inside...
The first pic below shows the large fraction of cable as I was able to retrieve. The second one zooms into the broken end.
[attachment=4411... Read more >>
Ok, I was cleaning my bike and as I was wiping down the seat tube, the front derailleur cable flung out, as the allen screw wasn't very tight...
I looked up several videos and followed them to the best of my ability, but I can't get the slack out of the cable...
I thought that the white things on the cable housing in the 3rd picture were the barrel adjusters referred to in videos, but turning them has no effect.
Please help ... Read more >>
Hi all, my friends road bike is knackard and it's up to me to fix it. I've compeltely overhauled the bike and it's running fantastic apart from one minor, annoying little problem.
The bike used to use those horrible lever-pull shifters below the handlebars however I changed to a pair of Shimano 7-speed rapid-fire shifters with integrated brake levers and the problem now is that the frame lacks the neccesary cable stop boss, and so far I've been using duct-tape and a bunch of cable-ties however this is just not strong enough and the cable is moving when shifting the gears on the re... Read more >>
I have just replaced the rear gear cable, the bike now runs and shifts okay but in certain gears there is either a clicking sound or the chain jumps a gear unexpectedly. Is this a tensioning issue? I have tried adjusting the mech via the rear barrel adjuster but it hasn't really helped...... Read more >>
[attachment=4121][attachment=4121]I have a Sillhoutte and the shifter cable housing has a 90 deg. bend at the downtube connection.The opposite side shifter does not have this bend.Is this a possible bend that has been done by an incorrect cable housing routing.It just looks to be to much of a drastic bend.... Read more >>
I'm attempting to put new on a bike where I never saw the old housing. I have a center pull cantilever brake and I'm wondering if anything has to go on the end of the housing before the cable connects to the link wire.... Read more >>
My cable guide on bottom bracket is a press on type and doesn't have a screw.
Looked around the 'net for a replacement but all of them have a screw.
This is for an older Black Diamond, "Ascent" model mountain bike that I just got and need to get in shape.
thanks... Read more >>