Through Frame Cable Routing
 

So, I made a mistake this morning. I pulled the cable on a inner frame routed setup. Stupid move, I know. Luckily I only managed to make this mistake twice, so I still have two cables to go before I have to REALLY struggle.

Here's the thing, most other through frame routed cables (at least the ones I've worked on), run the housing through the tubes so all you have to do is run the cable within that. Unfortunatley, my experience with changing the cables stops there.

On this particular frame (a Klien Quantum II) the housing runs up to the frame, stops, and then the cable runs through the frame on it's own, meeting up with housing on the other side. I have no idea, even with the cables that actually remain in the frame, how to change them. The openings don't seem wide enough to allow a second cable attached to the initial to be pulled through, so I am at a complete loss as to how to solve this.

Thanks in advance,
Sherwood

Remove the seatpost and see if the top tube is open where it joins the seattube. If so you should be able to get a finger in there to guide the cable into the exit hole. I was able to do this on an early '90 Trek.

That works only for the rear brake. The rear deraileur cable is on the downtube.

Hmmm... I wonder if this could be why Shimano has stuck with external cables for so long.

if you have already pulled the cable out (and or the slim plastic tubing out) then its time to start fishing for the hole with the cable. It is a PITA but next time before you pull the cable get some of the slim plastic tubing that fits over cables and run that up the cable and gently pull the cable out while making sure that your feeding the tubing trough also. Now you will have a guide to run the new cable.

Maybe you can do a similar thing by removing the bottom bracket if it exits somewhere around there.

I've had to do this on my S-Works Transition frame. It is a little tricky.

I hope that you have a Carbon or Al frame - Its Aluminium, right?

The hole should be wide enough to fit a needle and thread or a 25mm nail with thread attached.

The thread should be a good 5 foot long so that you can pass it

Tie the other end of the thread to the end of the cable that you want to pass through. Use a fishing knot to tie it on.

Drop the Needle/Nail into the hole and use a magnet to move the thread along. (A spoke magnet works well).

Gently push the cable through and use the thread to guide it.

I'd use an old cable to practice. It takes a bit of time to do it in the first place, but once you get the hang its fine.

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One possible method is to put a vacuum cleaner hose at the cable's exit end hole of the frame and pass a piece of thin thread into the entrance hole. The vacuum will often carry the thread right out the exit hole. Then use the thread as a guide to pull the cable through.