Internal Frame Cable routing
 

I'm getting ready to remove the front and rear derailleur cable end caps to pull cables back for installation through a new frame. I would like to keep cable ends from fraying while reinstalling, passing them through cable housing and frame downtube. I am considering super glue or wrapping the ends tightly in clear tape. What works best.

Not worth the effort. New cables are not that expensive. Roger

super glue 'might' work, but tape won't fit through the housing. To echo rhenning, if pushing the cables through results
in fraying/unraveling use the old RD cable for the FD and get a new RD cable. Old RD cable unlikely to unravel enough to
be too short to cutoff the bad part at the FD. OTOH if cables are a few years old better replace as the normal failure is
within the brifter, which is the worst place for a cable to fray/break.

This is what I do. If cutting off the end of the rear derailleur cable makes it too short, it now becomes a front cable.

No no no. Use new cables AND housing. Do not cheap out on this, it makes no sense.

I tried the super glue thing once. It worked. Have not tried it again.

If you are doing something like moving shifters that have new cables to a different bike tape will not work, super glue can work.

I hate trying to route the new cables through the Campagnolo Ultra Shift shifters . There's a tough bend positioning the cable end to come out of the housing and into the opening where the cable housing accepts the cable. I'm going to order a new RD cable and see if I can re use the existing cables first using super glue.

Sometimes routing cables sucks but when building a new bike it is always good to start with fresh cables and housing to get the best out of the bike. Buy less coffee or one less CD from Columbia House or something like that, don't cheap out on cables and housing.

Internal routing? Housing liner slid over the inner cable before the cable is pulled from the frame is a big friend. If you can't slide the inner end into the liner due to fraying then replace the inner. Andy

I usually just use the old housing to fish the new housing through the frame. I first cut off any ferrules from the ends of the old housing then I tape the end of the old and new housing together using a good strong duct tape then I pull it through the frame by carefully pulling the old cable while pushing the new cable.

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...heatshrink tubing (the stuff electricians use) is your friend. Works very well to join the end of the old cable and the new one for the pull. But I have never tried to get it to go through outer housing, and suspect it won't work for that. My pulls have always been for internally routed cables where the housing ends at the internal frame insertion.

Unless it's some sort of emergency, I never re-use cables that have been pulled out (except for sometimes converting a cable from R to F duty). As others have said, cables have a finite life, are not expensive, can be a pain to reinstall, and if they fail they are likely to cause other problems.

Expensive is of course a relative term, and so everything I take off a bike is evaluated for future use ;)

I once paid $30 for a full set of Campagnolo cables. I thought it was too much but the bike it was going on was worth it to me. Best cables I have run into with nearly no perceptible resistance. Would buy them again for the other bike that is all Campy. Wait... all the road bikes are! Ouch!

I am the same.. I patch tubes, keep old spokes bundled together have a pile of worn tires for trainer or emergency use, and stop and evaluate abandoned bikes by the side of the road for usable bits. Nothing that comes off a bike is necessarily going in the bin EXCEPT for rear inner cables. My cost-benefit analysis includes the potential time and hassle of trying to fed a frayed cable through the housing, and the likelihood that it'll seem OK but problems will materialize when trying to set the thing up. I can tolerate the risk in a cable that has been cleanly cut into a shorter cable, but that's my limit.

...you can buy die drawn cables made by Jagwire. They are very smooth, with little friction in a lined housing.