Hello, this is my first ever Reddit post! I’m coming to you guys because I can’t fish a new shifting cable down to my rear derailer on my old pink Nishiki road bike. I bought this bike about nine months ago and everything was working fine when I purchased it. Then during a ride with some friends the cable snapped by the bottom bracket I believe. I decided I’d give it all new cables so I started with the brakes and everything went fine. Then moved onto the shifting and started with the rear derailleur and immediately realized it wasn’t going to be as easy as the brakes were. It seems to be stopping and hitting something at the bottom bracket, where the last cable snapped. Since the old cable broke I wasn’t able to use it to run a new one through sadly. Anyone have any experience with old Nishiki bikes that can give me some tips? If you need any information at all from me I’ll do my best to provide it! Thanks in advance!!!
Cant fish cable down to rear derailleur
byu/GEN1David inbikewrench
by GEN1David
10 Comments
Use a strong magnet to guide the cable through the tube. You could also remove the bottom bracket so you have a better view of that area.
With a carbon, titanium, or aluminum frame, my answer would be a neodymium magnet in a sock. Might still work with a steel bike. Not sure. Last time I had to do it, it took me hours of trial and error, and I was just doing a brake cable through a top tube.
That’s a hard bottom bracket to get out too. If you’re good with tools get the spanner to remove the lock rings. If not take it to a shop, have them rebuild the the bottom bracket, and then ask during that process if they can pull the cable through. Ask them if they have plastic cable routing tubes. The next time you need to replace the cable, you run it through the end to the shifter, it creates a temporary channel to guide the cable through. I’m not explaining it well but your local shop can show you, I’m sure with modern bikes they have to do this all the time.
Put a plastic cable cover in the outlet by the derailleur and fish it backwards to your cable inlet. Then run the cable in through the cable cover.
If none the suggestions work, try getting a very light and thin piece of string (like the ones uses for sowing) put it through one whole and use a vacuum to suck it on the other end of the frame. Then use the string to guide the cable. Good luck
I’m really good at this but it’s hard to explain.
What you do it get a length of cable in your hand that reaches all the way to the opening plus some extra. Hold it outside the tube and look at the cable. Put a bit of a bend 2-3cm at the end that bends towards the opening. Don’t let go of the cable. In your mind keep an idea of where the small bend is aiming to. Then put the cable in into the down tube to the bottom. Then just keep stabbing at the bottom with the cable. Keep about 10cm extra length. Just keep stabbing. Then start rotating the cable a bit clockwise and counter clockwise. Just keep jabbing the cable at the opening and giving it rotations to allow the bend angle different each time. Shots on goal here.
When it goes through, stop.
https://preview.redd.it/90fuq5trv01h1.png?width=900&format=png&auto=webp&s=d8a5e56a13aade51d84c13e1afd3bde18041a06c
Get yourself a set of these. Park tools I.R 1.3 internal cable routing kit. Pricey but you’ll never have to worry about internal cable threading again.
Assuming you dont have a cabling kit which normally includes a magnet and guiding wire with magnetic heads. As other mentioned vacuum is one other method. The other is to use another cable and thread from the bb end back up as the entry side is much easier to thread through, once the guide cable / old cable is through, tape the new one and pull (and push) the new one through
Use a magnet
It’s a steel frame. Magnets will not work. Vacuum technique or u/Mindless-Baker-7757 stab technique. Not magnets.