Bicycle Mechanics - Help!!!

I am hoping some of you seasoned wrenches out there have a practical solution to my problem. I have a carbon fiber frame with an internally routed rear brake cable. During the build, the plastic guide tube inside the top tube was accidentally pulled out :cry:
Any tricks for re-threading the guide tube through the top tube without trying to fish it through blindly?

Thanks in advance

lol.. good luck with that one :)

But you have a chance... use something like dental floss or another type of material, and use the vacuum cleaner to pull it out thorough out the other side... Just fish it as much as you can (as much as close of the other end) with the cables and use the vacuum cleaner to get the tip of the dental floss at the other side, if you are lucky it will work fine. Havent done this ever but i have heard it works.

Good luck :)

ps: never dispose of the darn tubing also.

Oh, I have it! It's just not where it needs to be! lol

Flying blind here, as I'm a wrench who did most of my work before the days of carbon fiber, but try this. Find a place that sells magnetic jewelry clasps and buy one. Has two very small magnets mounted to rings for attaching to the end of a necklace. Attach each to some stiff wire and feed into opposing holes until they click. Pull one end through, feed the wire through your plastic guide and then feed the guide into the frame. This solution depends of course on the entry holes being large enough, but the photos I've seen of th clasps show them to be quite small. Good luck.

That was the best solution I came up with as well. I found magnets of all shapes and sizes online and I ordered a few different cylindrical configurations that will fit the entry port. My plan is to epoxy two magnets to the ends of two steel cables and have them meet in the middle. Never though of the jewlery clasp though. Sounds like a cleaner solution than mine but my magnets are ready ordered. I'll keep you posted with results.

I haven't found it to be as hard as I thought it would be. My trick is to position the bike so that the exit hole is on the bottom and just thread an ordinary brake or shifter cable through. I use the elbow end of a spoke to snag it.

That is another good idea. Not sure if I have any spokes laying around or that the elbow would pass the entry port, but I'll try with some thin steel with that I can bend a hook into the end of.

151157There is your answer! A beaded chain and a magnet. I used a wheel magnet from an old computer and bought a beaded chain at my local hardware store. I realized that my best shot would be to make the tube vertical so that gravity would pull my guide string straight down. I also realized that I would need something that was more flexible and could articulate as opposed to something stiff like a brake cable. I hung the bike so that the top tube was vertical. I measured the length of the run on the chain and marked the spot of insertion that would get the lead edge to the exit port. I inserted the magnet into the exit port at the bottom, holding it with needle nose pliers, and slowly lowered the beaded chain down the tube. I had contact on my first attempt! What was essential was that I could feel the realtion between the tip of the chain and the magnet. I knew when the chain was stuck to the side of the magent as opposed to it being tip to tip which is the only way it would come through. After all of about one minute of "feeling" my way around I got the chain to settle tip to tip and gently pulled the magnet and chain out the exit port. I then scotch taped some thin fishing line to the chain and pulled that back through, then taped that mono fishing line to my brake cable and finally pulled that through.