How to replace gear cables?!

[Emoco]

I'm completely lost.

I can't figure out how to get the old cable out of my rapidfire shifter to save my life.

How on earth do I do this?

 

[ridevintagemtb]

The side of your rapidfire unit should have a little port with a rubber stopper over it (you might have unscrew). Pull the stopper: this is the cable entrance. Shift the shifter all the way down until you can see the inside mechanism rotate through with the cable end. You should then be able to reverse slide it out.

 

[gump]

..unless its an M737 XT, where there are two wee tiny screws to undo and remove cover - NOT the silver ones whatever you do!

 

[Emoco]

Right, I've figured how to get the cables in. Now, when I take up the slack with the front mech and tighten the allen bolt, the shifter doesn't do anything?

I've never done this before. I can't afford to take it to a shop though.

 

[ridevintagemtb]

http://parktool.com/repair/readhowto.asp?id=117

 

[Inigo Montoya]

was in the same situation 3 month ago when i assembled my first bike. what helped me quite a lot was shimanos techdocs. see for example this http://techdocs.shimano.com/media/t...eSystem/SI-R650D-En_v1_m56577569830611900.pdf
pdf document. it describes the whole process for a quite current deraileur and shifter but you get the idea.
http://techdocs.shimano.com/techdocs/index.jsp

 

[Err]

First, make sure the barrel adjusters are fully screwed in before beginning, ie the inner metal past is fully retracted inside the plastic knob. Set position of derailleur with appropriate limit screw.
Pull cable with pliers, and clamp with the bolt. Then use the barrel adjusters to adjust indexing.
Set the other limit screw.

My main difficulty when i first tried to do this (following park tools) was not understanding and therefore ignoring the barrel adjusters, and trying to apply sufficient tension with pliers alone.

 

[Emoco]

The barrel adjusters (like on my V's) turn but don't seem threaded. They don't screw in or out.

 

[Err]

The plastic part stays in the same place, and moves a metal piece in and out. Iirc, the metal part is pushing the cable outer outwards from the body, increasing tension on the wire, moving the derailleur away from its rest/no tension position, ie closer to making the first shift.
There's also one on the rear derailleur. Look at a working bike and you should be able to see the metal bit protrude a little.