Welcome to Shimano hell, I'll be your tour guide. Don't get me wrong, I'm a Shimano fan - they make great stuff. However, I'm cursing 'em a bit at the moment...
Replaced the rear derailleur cable on my zippy Ibis carbon road bike, which runs Ultegra STI shifters. Piece-O-Cake, done in no time flat, been through this routine before. Bike in workstand to adjust shifting - won't shift all - nada, ziltch. What the heck?
Closer inspection reveals cable end in shifter not sitting where it should be, appears to be above the grooved slot. Either I threaded the cable incorrectly, missing the grooved slot and housing (most likely), or the barrel cable end somehow pulled through the housing (unlikely). No big deal, I'll push the cable back through the shifter and reseat. Not so fast Bunky...
After an hour of screwing around, along with an additional 20 minutes from a neighbor - seems to be impossible to push the cable back through - gap is too tight. Attempted to push cable with a thin awl from the back - sorry. Grab from the front with needle nose pliers - sorry. Removed two screws to hopefully access via plastic hatch - sorry.
Cutting the new cable would do nothing but allow the cable end to drift somewhere into the shifter housing. Crap!
Considered removing pivot bolt lock nut and see where that gets me. I chicken out knowing STI shifters are not really designed to be taken apart. You can just see the tiny springs, spacers and various watch like parts waiting to explode all over the garage.
After some online searching, discover this is a fairly common problem, though usually occurs when a worn cable snaps in the shifter, leaving the barrel end stuck. My dilemma is similar, though my cable is intact. From the online pics and stories that I read, some wound up buying a new shifter after unsuccessfully trying to remove the cable - some bike shops unable to remove as well. Others drilled a small hole into the shifter housing to access the snapped cable. Most removed after hours of poking and prodding with various awls and dental type tools.
Man, you'd think Shimano would have designed some kind of access hatch to remove a broken off cable end. Replacing an expensive shifter assembly because of a broken cable is just plain nuts. Even though my problem appears to be self induced, amazing that I can't easily remove the cable.
I plan to cut the new cable a few inches back and remove the shifter from the bike. Then sitting a table with good lighting, can twist and access the shifter internals as needed. Neighbor lent me a thin awl and really skinny needle nose pliers to poke around with. What a pain in the uh, shifter.
Wish me luck.