Fixing T's bike's front derailleur cable/housing

This is the bike I used to ride before getting the Cannondale that I ride now.  T has been riding it the past few years.

The front derailleur shifter cable "broke" and won't change front gears.  It's stuck in the smallest front ring...

Triple rings.  The largest gear is 52 teeth (that's pretty big by today's standards).
T usually rides in the middle ring...

The rear is a 9 speed setup with an Ultegra derailleur (second to the highest in the Shimano lineup -- only second to the Dura-Ace).

The shifter cable housing has a plastic outer layer, a steel wire reinforcement layer then an inner plastic liner for the shifter cable to run through.  The plastic outer layer and the steel reinforcement are worn and broken.
The cause appears to be from the cable housing rubbing repeated against another cable housing (the one for the rear derailleur).

Somewhat of an unusual failure...

The cable housing is pretty short.  It's only about 16 inches(? - didn't measure it...) long and it terminates here near the top of the downtube.

The cable keeps going and ends up clamped here at the front derailleur.  First thing is to remove the old cable and housing.

First, I cut off the crimped end of the old cable (using some strong cutters, so that the cut is nice and clean).

After cutting off the old cable end, loosen the clamping bolt.

The front derailleur cable routes under the bottom-bracket area of the frame through a plastic cable guide.  The cable being replaced is the one on the right in this picture.

The other end of the shifter cable is inside the shifter mechanism at the handle bar

The "thumb" shifter has two levers that are pushed to either go up or down the three front gears (the bigger lever is for going "up" the gears -- moving to the larger rings).

To get to the other end of the shifter cable, the three outer screws on the shifter mechanism are removed.  Although there's a little bit of corrosion on the screw heads, they came off easily.

After removing the screws, the cable end is visible (it's routed through the white plastic part inside).

The cable comes through the shifter housing, as seen in this picture.

The lever mechanism, with the cable, is pulled completely out.  This allows the cable housing to be removed from it's location on both ends (the cable housing is just "located" in slip-in fittings on both ends & don't require any tools to remove.  Simply pull it out.

Another picture of the damage to the cable housing...

Using a cut-off tool (air powered in this case), I cut a piece of new housing to length (the new cable housing is silver & is to the right of the cut-off saw).  Then, I used some drill bits to deburr the metal reinforcement inside the cable housing.  Also, a file was used to deburr the outer edge of the metal reinforcement.

After cutting and deburring.

Added the cable housing ends to the new cable housing.

I used a braided reinforced cable housing meant for brake cables.  The brake cable housing is slightly larger than the old shifter cable housing but it's the only housing that I have that's not white.  (white cable housing would clash pretty strongly with the existing black cable housing on the bike).  The cable end for the shifter end of the housing was a little tight to put on but it will work.

This is the other end of the new cable where it will sit in the retainer on the downtube.  Here I can use a larger cable housing end that fits easily.

While reassembling the front derailleur cable, I noticed that the rear derailleur cable end was missing it's end crimp and was fraying & corroding.  Will fix this too...

Reinstalled the shifter, new cable housing and cable.  Routed it properly and the cable terminates at the cable clamp on the front derailleur.  The cable is left extra long initually.

After getting things installed and adjusted as well as I can,  I cut the new cable to length and installed a cable end cap.

I cut the rear derailleur cable and installed a cable end cap.

New front derailleur shift cable housing, as installed.  Although it's not black, it blends in OK with the silver bike & other silver components.

The new shifter cable housing as it enters the shifter assembly.  The mechanism at the end with the "knobs" on it is for making fine adjustment to the cable to allow adjustment to the front derailleur shifter cable length, without using any tools.

The new cable housing as it sits on the downtube retainer.

Cable housing routing.  I put the new cable housing behind the rear derailleur cable housing.  Although they touch, there's no real tension when in the straight ahead position.  I'll put some tape on the rear shifter cable housing where it touches the front shifter cable housing for some extra protection...

There are two adjustment screws on the top of the front derailleur that controls how far the derailleur is allowed to move.  The one of the top of the picture controls the lower limit (how far the derailleur can move when moving towards the smallest gear).  The one on the bottom of the picture controls how far the derailleur can move when shifting to the biggest gear.

The bottom adjustment screw is too far "down" and doesn't allow the derailleur to move far enough to engage the big gear.

Better picture of the screw end...

The adjustment of the derailleur's height is also important in getting the gears to shift smoothly and to keep the chain front rubbing against the sides of the derailleur chain guides when just riding (not shifting).

Unfortunately, the bottom screw is stuck and I could not get it to come out (I tried penetrant, different screw drivers and even an impact tool, to no avail...).  I'm going to have to drill the screw out and replace the screw...

The screw head is pretty damaged from all the removal efforts...

A job for another day.

For now, the shifter works in the lower two gears, which is really what T rides in.  It would be very rare to need to use the big ring (you'd have to be going around 20 MPH or more to really need to be in the big ring...)