Any helpful Tips for Internal Cable Routing?
 

So I am near completely done building up my new bike but I just have to do the cables and chain. Problem is it is internal cable routing and it is a PITA. Any helpful tips?
This is the bike as it sits. Should I do the cables before I do the BB? in other words, should I remove the bottom bracket and crank?

Tom from SuperiorLite said do use a paper clip or a magnet and hold the frame front wheel up.

At this point I am considering the string and vacuum technique. But there has got to be a better way no?

http://liveoncenjoy.com/SMF/MGalleryItem.php?id=666

Internal cable systems vary. Some of the better conceived ones provide for easy replacement with funnel-like guides at the far end. Others reckon that you'll install the cables before the BB,and use the open shell to help you. The nicest ones have a continuous tube inside.

You have to get creative on some. I've heard of the magnet trick, but it's useless on steel. My 2 bikes with internal cables have internal guides, and a removable plastic cover/cable guide under the BB. When working on bikes without intelligent design, I've had some success using a needle threader to retrieve the wire at the far end.

Join the club of frustrated mechanics. Andy.

Things like this separate professional mechanics from DIY cyclists. Internal cables can be a thing to consider before buying and DIYers can avoid the worst ones. But Pors have to deal with everything that comes in the door.

To the OP, many frames with internal cables come with a pull already installed. Don't just pull it out. Using a variety of techniques you can use the pull, or an old cable to pull the new one through.

Tomorrow is another day. I will try Taking apart Crank/BB and seeing if I have any luck. I will also try stronger magnets. That's for the help so far.

When you have open, post details of what you have, ie. brake or gear. Is the rear wire also routed through the chainstay? and if so how is it routed through the BB.

Also before you start, bring an inner wire (brake or gear or both) to the hardware store or Radio Shack, and buy a length of electrical "spaghetti" (thin tubing). You want the thinnest that the wire fits through, either free sliding, or so you can push it up a ways and have it stick.

It'll come in handy to thread the wire.

A few tips. Make sure the cable is strongly magnetic if you're trying magnetics. Put a slight cock in the cable end, about 1" long and about 20* or so. Twist the cable about as you feel for that hole way inside the frame. Place a strong light (I often wondered about marketing a stay/frame tube mountable light that can be pointed as needed) pointing into the exit hole, or the entry hole while feeling/looking for the cable's routing. Use gravity to help place the cable near the exit port. If there's a access panel or plate that is removable then a spoke end curved into a slim hook can grab a cable end through the opening.

I've never tried the vacuum method but have gotten close a few times... It takes a lot of patience, what some might call insanity (trying something over and over) and the touch/skill/luckily to know just when to freeze your movements and push the cable through.

Many times, as i have tried to get that cable to catch on the exit port, I think of the neighboring locksmith (to the LBS i owned for 15 years) when I needed his help on day. The front door lock had closed and latched and the key didn't turn the internals any more. No way to take the lock apart, the key was useless, the door hing pins had been welded on years before and I both needed a front door to do business as well as be able to secure the shop at closing. So i walked the 3 store fronts to his shop and explained the situation. I expected some special tool, secrete back door knowledge, his years of experience to open the door. But what did he do? He very violently shook/worked/massaged the door and deadbolt latch for about 10 minutes. The frame and front windows vibrated with his efforts. And then just like magic the deadbolt latch turned and the door opened. He explained that on old and worn stuff sometimes you have to give the parts the chance to have all their various spatial relationships occur. It's only one that will be the key. (He then took the lock apart and dove into his basement to find less worn parts to "fix" the lock). I took from this that random chance with a determined touch can do the job. Andy.

Tape a vacuum cleaner to the hole you want the cable to exit from - tape up all other holes except for the entry one.

If you feed nylon fishing line in (with the vac on, of course) it will likely find its way out the exit hole..

Once you have a fishing line through pull a good amount of slack through at each end. You can then either tie it to the end of your metal cable to pull it through - or sometimes you can hold the fishing line taut in place while you slide the internal guide outer in around the line.

If you're gonna use a vacuum, mouse it first with wool.

I don't quite understand what you mean here.

I've used the vacuum-and-string" method but I use fine sewing thread as the string. It's very light and flexible and finds it's way to the exit more easily than anything heavier. Use the thread to pull through a stronger string or cord and use that to pull the inner wire. Then use the inner wire to guide the housing.

I was thinking of thread but figured it wouldn't be strong enough. I didn't consider a transitional string. The housing is not internally routed, just the cable itself. I am sure I could route sheething as well internally to make it easier for next time.

Usually, new frames come with guides installed. Don't pull them out until you are ready to install the cables, and tape them in place while you work on everything else.

Taking out the BB will be the least frustrating way to deal with shifter cables. By far. For the rear brake, usually I'll just shove the cable in, and fish with a paperclip bent into a narrow, short "J" at the end. Hook the cable, bring it to the hole, carefully back the cable out until the tip is at the improvised tool and then gently pull it out. It will slip off a couple times before you manage to get it...

When changing cables and housing in the future, leave the housing in place, take out the cables, and then run the new cables in reverse through the housing so that the heads are sticking out where the RD cable will come out, FD cable comes out, and brake cable comes out. Remove the housing from the front of the bike and you should have cables sticking out of the cable/housing entry points. That way, when you go to install the new housing, you can use the cables to guide the housing through the frame, remove the cables, and install.

Here's a trick that has worked for me. Once I figured out how to position the frame it was literally a 1 minute job. Might not work on every frame.

1. Position your frame so that the cable exit is facing straight down.
2. Run the cable and watch for when it passes the exit hole.
3. Snag the end of the cable with a piece of wire or something.

Once you have a cable threaded, you can replace it easily by sliding a thin tube down the old wire until it's out at both ends, pull out the wire, thread the new one down the tube, then pull out the tube leaving the wire.

BTW- as for the thread not being strong enough, it doesn't have to pull the cable, only a slightly stronger thread. Take a hint from how John Roebling strung the first cable for the Brooklyn Bridge. He bet a kid that he couldn't fly a kite across the East River and land it on the other side. Once he paid off the winner, he used the kit string to pull a heavier line, and progressively worked his way up to a rope strong enough to pull a steel cable across.

This is exactly how I do it, except that I use a sewing needle threader which opens up to a large target inside the tube, and can be used to pull the cable out. Since the cable can't double over to exit, you use the threader to pull it against the side of the hole, and slowly pull the cable back until you see the end, then push it out the hole. It takes a bit of touch but works every time.

My old man used to work on yacht masts; poking a bit of string through to pull ropes and wires into place is called mousing.

If you use a vacuum to suck out the thread you're mousing with, you're best off using something like cotton or wool that will be most affected by airflow.

So the updates are I had like an hour to work on it this morning before work. I was able to get the brake cable done by done it backwards with a spare cable. it was much easier to pull the cable out of the headtube than trying to poke it through the tiny little hole. I then taped them together to create a little housing for it and pushed the new cable through while backing out the other one.

I have only attempted the FD cable once and have it half done. I will have a couple of hours to play around tonight. hopefully it doesn't take that long. But I'll fill you guys in. Then I have to rebuild it all ;) As pretty as it looks, what a pain....

Might try soldering the new cable to the end of the old one.

There are a number of fairly simple ways to replace an internal cable. However, it seems that the OP is struggling to get the first cable(s) into a new frame.

Correct. And not struggling anymore. With the help of a very dedicated friend, we managed to get it all routed. the RD cable was a pain in the arse. And I hope that i never have to do that again from scratch. Replacing cables is a whole different ball game then running them in the first place.

Anyways, time to rebuild the bike and get this thing over with. I will fine tune over the next week or so.

So I take it you're gonna secure a bit of string to any cables you remove from this frame in future...

I may have cut the rd cable housing a little short, but I will test it out before I do final grip tape wrapping. But here it is for now. I still need to do the grip tape, tune the derailleurs/brakes and have some fun.
http://liveoncenjoy.com/SMF/MGalleryItem.php?id=667

Of course. As said quite a few times. This was new frame and this was the first time doing this. If I was just replacing cables that were already there, this thread wouldn't exist.
;) I do thank everybody for their help though.

I ended up using a combination of cabling from both ends and then joining them together in the bottom bracket and pulling them through. Combination of Super glue, Electrical tape helped connect the ends of the cables.

Chain looks a tad long :)