Removing gear cable from rapidfire shifters

[JediGoat]

I'm changing very old rusty gear cables, and cannot for the life of me work out how to get the end of the cable out of a Shimano rapidfire shifter (I think that is what they are called - the ones mounted on flat bars with finger and thumb triggers).

I've done some googling and the general consensus is "Don't open the shift mechanism or you will burn in hell". There are two plastic bits and a spring which surround the cable and screw into the trigger housing ('scuse my technical terms). I've unscrewed these, and now I can move the cable back and forward a bit, but cannot see how to get it out so that I can install a new one.

The is a very tempting big screw on the top, but my don't-do-it meter tells me not to touch that.

I'm assuming there is a simple answer to this, but after going through this forum, Sheldon Brown, Park Tools, Bicycle Tutor, two books and google, I'm still none the wiser

Jo

 

[gbb]

There are two very small pozi screws on top of the top plastic cover. Remove them and this will expose the pulley/ratchet and cable. Pull back the cable outer and push the inner cable into the shifter. You'll see the nipple then. I used a small screwdriver to lift up the nipple...it 's a bugger to get at with you're fingers.
Quite straightforward, nothing falls out

 

[gbb]

Give me a few minutes...i'll post some pics, just to make sure we're singing from the same hymnsheet

 

[JediGoat]

Well, there are two tiny screws on the bottom which seem to hold the gear display bit together.

One big screw on the top, which appears to hold the unit to the bars.

And one small screw on the bottom which holds the circular housing for the lower lever. When I remove this one I can see the mechanism, but there's still stuff in the way of the cable - i.e. I can;t see where the cable ends.

 

[jpembroke]

Before you go dismantling the shifter first make sure there's not a portal just behind the short thumb shifter on the side of the unit. It may have a 6mm wide plastic grub screw (which comes out with a single turn) or that may be missing in which case it'll e a hole. Drop down on to smallest sprocket and push cable. It'll pop out of that hole.

This is how you access/fit the cables on most Shimano shifters. However, as discussed above, there are those you actually have to open up to remove cables.

 

[gbb]

This is why i hesitated, can't remember if these are Rapidfire or Ezfire....
Top screws...

Top off exposes the ratchet etc...

If yours are the same, its quite straightforward.

Actually, i talked about usung something to lever up the nipple so you can get to it....may not be neccessary.

 

[JediGoat]

Before you go dismantling the shifter first make sure there's not a portal just behind the short thumb shifter on the side of the unit. It may have a 6mm wide plastic grub screw (which comes out with a single turn) or that may be missing in which case it'll e a hole. Drop down on to smallest sprocket and push cable. It'll pop out of that hole.

Yay!

Good grief I would never have noticed that if you hadn't said it. Thanks a lot

 

[JediGoat]

Thanks for the pics gbb, but that isn't the one I have.

The hidden 'pings about all over the room' mini plastic screw was the key.

Now all I have to do is work out how to reconnect it to the front shifter

 

[gbb]

Thanks for the pics gbb, but that isn't the one I have.
The hidden 'pings about all over the room' mini plastic screw was the key.

Now all I have to do is work out how to reconnect it to the front shifter

No problem,

 

[jpembroke]

Thanks for the pics gbb, but that isn't the one I have.

The hidden 'pings about all over the room' mini plastic screw was the key.

Now all I have to do is work out how to reconnect it to the front shifter

Ah, front mech. OK: fit new cable, run it through housing and clamp it to mech bolt whilst pulling cable taut. N.B. When you clamp the cable make sure you take note of the feint cable groove on the back plate behind the clamp bolt or on the bolt itself. Your mech may also have a tiny leverage tab - the cable needs to run over the top of this not behind it, before it is clamped (see link below for example and description).

http://www.hostelshoppe.com/tech_frontderail.php

Once you've done this take up any slack with barrel adjuster on shifter. Not too much though or you'll start to adjust the mech position. It should then shift fine - nothing to it!

Mind you, if your old cables were rusty then it is advisable to change the outer housings too. Chances are they'll be rusty inside which can result in snagging cables.

 

[JediGoat]

Ah, I may have to look at that page when I replace my new cable that I managed to fray

I seem to have spent all day cutting cables and cable housing, but for some reason, as soon as I cut that one, the darn thing just started to unravel.

I'll have to get a new one tomorrow and put it on. As for the routing over/under/around tabs, I was rather confused as to how to clamp the cable on at the front mech. The rusty blob that is the clamp seems to be able to attach in 3 or 4 different ways, but that guide should help me a bit

 

[jpembroke]

What front mech do you have and is the cable routed along the top of the frame or under the bottom bracket? If under the bottom bracket (or if down from the top tube, around a pulley and back up) then the leverage tab is important. On road bikes, where the cable is nearly always routed under the BB, you often see cables clamped incorrectly (i.e. pinched behind the tab) which seriously affects shifting, making it very clunky and practically impossible to set up.

Regarding your fraying cables: are you using good cable cutters?

 

[JediGoat]

I'm at work at the moment, but from memory it's a Shimano Deore (but I could be wrong there), and the bike is an MTB.

I checked the routing of the cabling before I removed the old one, and it was straight down the seat-tube and held under the left side of the clamp (the bit I'm not sure about is which way round the clamp originally fitted, as it kind of pinged off across the livingroom )

My wire cutters are not the best, but they managed just fine with all the other cables. I blame a half-hearted squeeze on my part

I have to get a new cable on my way home tonight, so I'll probably spend some time in the bike shop staring at various gear cable clamps on bikes to see if I can get any inspriration

Jo

 

[jpembroke]

If the cable is routed from the top and straight down the seat tube then clamping it is pretty straightforward. Should be obvious. The leverage tab is only important when the cable is routed via the bottom bracket.