Has anyone replaced a rear deraileur cable on an Eddie merckx EMX-3 (current) frame? any advice? The inner cable only goes through the frame, with a very small exit hole at BB. Bike is newish and i would like to take it completely out to see if theres any crap in frame? gears not working properly? too much friction somewhere, I think?

Don't. At least, don't unless you run a small tube around the cable before you pull the cable out. Otherwise, you'll never be able to get the cable back in.

What makes you think there is something in the frame?

Internal cables are known for having more friction, even when new, compared to traditionally routed ones. Some bikes will have a section of low friction liner tubing that the inner goes through to try to lessen the friction. Sometimes this liner gets contaminated with grime or corrosion. The entry and exit ports are also points of friction, where any low friction liner is not likely to be present. IMO internal cables are a poor solution to the need to be cool. At work we will charge more to replace such given the longer time they take.

Modern bikes are starting to make the fishing out of the cable (during replacement) easier but this is not consistant and some brands do a better job then others. The suggestion of sliding a liner over the cable before removing said cable is a good one, if the liner can go all the way through the frame and come out again. Many times we find that we have to pull the BB out to deal with the cable's routing through the shell, espicialy with older bikes (think steel).

Wanting to check out the insides of your bike is a good thing. Water will get past any seal or clamped opening given time. The desolved crap in water won't do the frame or internal cabling any good. Also we find that the factory prep and install of BBs and headsets is often lacking in detail/amount of grease.

Expect to have to do gear cable maintainance periodicly, more often then with external cables. Merckx bikes are not popular enough for me to have any specifics about the cable routing memorized. Maybe asking at the shop that you bought it from for any insights. Andy.

My problem is that the gears change fine when indexing all the way up (10 speed ultegre) to a big gear, but indexing down on third and forth largest cogs dont aling up, the deraileur settles a fraction more towards the hubside?? anoying! the bike is newish, all in good nick, chain is on correctly, etc, so its fault finding time....

Id take the BB out, any crap in the frame will settle to the lowest point.

We've been finding issues with the new Ultegra shifters. The redesign that brings the shift cable under the bar tape seems to have also brought friction issues.

Whenever you pull cable from an internal housing bike, get familiar with how the cable is run through the frame. Some frames come with a removable guide, some come with a permanent inner guide. I'm not familiar with Merckx enough to tell you how the cables are run. If you pull the cable through the frame without a guide, it will be nearly impossible to run the cable through again.

You can try several different things to alleviate the friction. Making sure the frame is cleaned of any debris is a great start. You can replace the rear shift housing loop with a higher quality housing. Using a teflon coated cable will help as well. There are a couple of cable sets designed that may work. Gore makes various sets that I've had trouble using with some internal bikes but that cuts friction dramatically but there are others out there as well.

If the bike is relatively new, you can always take it back to the shop with the complaint that it won't shift right. At the very least, I would ask them how to replace the cable.

Good luck! Let us know how things worked.

Have replaced outer cable (gore ride on), inner cable, removed inline barrel adjusters, have packed away (from frame) BB cable guide with a piece of plastic 1mm sheet because the cables were slightly hitting frame. Gears are still not indexing down correctly where by chain rests slightly towards hub. I think its the combination of the latest handle-bar cable routed shifters and internal frame cableing that is giving me problems, back to bike shop now.

it was rear hanger that was out of align