Perils of self teaching from Youtube - gear cable ruined?

[Ajax Bay]

The cable adjusting bolt should only be used for fine tuning the indexing, not making major adjustments.

This.

with a stretched gear cable

Cables do not 'stretch', not even while 'bedding in'. Securing points and the outers the cable passes through might affect this though.

Not all of them have springs.

This (beaten to it by @smutchin ). Don't worry about the spring. Cable tension holds this together. If the design includes a spring (and this one clearly doesn't as it is not present and there has been no opportunity to lose it) it makes the adjustment a bit easier.
It is quite possible that the threads have been damaged as you incrementally unscrewed it and tested the RD. At the end (ie before it finally came apart) there would only have been a couple of threads engaged and the bending moment on the 'bolt' element would have damaged either its threads or, less likely the tapped hole in the RD. Looking at the diagram, it's possible the hex nut has twisted in the knurled body and is not square on to the bolt, thus preventing it screwing in. @smutchin has given advice there: poke out the nut if it will come out and screw it on first. I think it more likely that you'll have to square it up in situ.
HTH

 

[gazza1286]

The threaded part needs to be disconnected from the ferrule and outer cable and screwed back into the rear mech body. Unless you do that there won't be any adjustment available. Look on Google images for new rear mech to see how they look fresh out of the box.

Once you've done this. Give YouTube another chance. RJ The Bike Guy is without doubt the best resource.
See:


View: https://youtu.be/D5HP1poRjv0


Hopefully this will be give you the confidence to proceed.

 

[smutchin]

I would then surmise that turning the black adjuster counterclockwise pulls the silver part in.

Aha! I've just had a penny-dropping moment...

I couldn't work out how this design of adjuster works but what you say makes sense. It means the adjuster works in the opposite direction to a Shimano model - turning it counterclockwise shortens the cable (reduces cable tension), while turning the adjuster counterclockwise on a Shimano model increases cable length (increases tension).

This is a fairly important difference to remember when making adjustments to indexing!

I'm guessing the hole in the mech body isn't threaded and as @Ajax Bay says, it uses cable tension to hold it all together.

 

[Roadhump]

I managed to fix the barrel adjuster. The hex nut lodges inside the black plastic swivel housing and when I prised it loose (as suggested above), I was able to screw it onto the threaded part of the adjuster (the 1 cm threaded bit) and reassemble the mechanism, then put it back together. However, although the barrel adjuster now seems to work (I can see the hex nut is moving along the thread as the adjuster is rotated, and rotating it clockwise does make the derailleur move and the chain move up a few cogs), it only does so partially and getting the chain onto anything past the middle cogs (to the bigger ones, i.e. the lower gears) can only be done by pushing the derailleur manually - the range of movement is there but not via the cable as it should be.

Despite my very limited knowledge, I suspect 2 causes. The first is that I don't seem to be able to get the full length of inner cable exposed despite pulling it with pliers which pulled a bit more out but ended up just pulling the end clamp off. In the below photo the slight kink in the cable is probably where it was previously clamped by the retainer bolt.

The second issue seems to be the shifter which now seems to be very loose when using the lever to go down the cogs / up the gears, and when going the other way, it goes from a very loose ratchet type movement to very stiff quite quickly. At its stiffest, the cable is very taut, but just doesn't have any effect on the derailleur. I think the LBS is my next port of call. Thanks for the help offered.

 

[summerdays]

I'm assuming that kink in the cable was where it was previously clamped? (Edit I reread your post and realise you have said that) If so then you need the cable a bit tighter than you have currently. I struggle to do that myself so I bought myself a 3rd hand tool which helps to pull the cable whilst your hands tighten the bolt.

 

[raleighnut]

I managed to fix the barrel adjuster. The hex nut lodges inside the black plastic swivel housing and when I prised it loose (as suggested above), I was able to screw it onto the threaded part of the adjuster (the 1 cm threaded bit) and reassemble the mechanism, then put it back together. However, although the barrel adjuster now seems to work (I can see the hex nut is moving along the thread as the adjuster is rotated, and rotating it clockwise does make the derailleur move and the chain move up a few cogs), it only does so partially and getting the chain onto anything past the middle cogs (to the bigger ones, i.e. the lower gears) can only be done by pushing the derailleur manually - the range of movement is there but not via the cable as it should be.

Despite my very limited knowledge, I suspect 2 causes. The first is that I don't seem to be able to get the full length of inner cable exposed despite pulling it with pliers which pulled a bit more out but ended up just pulling the end clamp off. In the below photo the slight kink in the cable is probably where it was previously clamped by the retainer bolt.

View attachment 337506

The second issue seems to be the shifter which now seems to be very loose when using the lever to go down the cogs / up the gears, and when going the other way, it goes from a very loose ratchet type movement to very stiff quite quickly. At its stiffest, the cable is very taut, but just doesn't have any effect on the derailleur. I think the LBS is my next port of call. Thanks for the help offered.

Did you select 'top gear' before removing the cable clamp, I suspect not. What you need to do is click the shifter all the way to it whilst pulling the exposed cable that runs along the chainstay, this will end up quite slack then you can reclamp the cable removing all of that.

 

[Roadhump]

Did you select 'top gear' before removing the cable clamp, I suspect not. What you need to do is click the shifter all the way to it whilst pulling the exposed cable that runs along the chainstay, this will end up quite slack then you can reclamp the cable removing all of that.

I can't recall if I did that when I first removed the clamp if am honest.

I suppose this shows the pitfalls of trying something you have never done before, and when you don't understand the workings of the mechanisms involved. I recall the Youtube videos saying you should change to the highest gear / smallest cog, but don't recall any explanation for this, and I may well have forgotten about it. Having played around with the cable and felt the difference in tension when the shifter is moved either way, i now understand why it is necessary to change to the highest gear to achieve maximum slack whilst working on the cable.

Having said all that, would it make any difference because after reconnecting the cable I did move the shifter to the position that would select the highest gear, if it was working correctly, and there was a lot more slack when I disconnected it again? Perhaps my naivety is showing again, buying that big blue book might be a good idea

 

[Jenkins]

Looking at your last picture, your cable run doesn't appear correct - it should be in the guide slots under the part of the dérailleur that the cable is against where the kink is. Here's how it should be...

 

[summerdays]

I suppose this shows the pitfalls of trying something you have never done before, and when you don't understand the workings of the mechanisms involved. I recall the Youtube videos saying you should change to the highest gear / smallest cog, but don't recall any explanation for this, and I may well have forgotten about it. Having played around with the cable and felt the difference in tension when the shifter is moved either way, i now understand why it is necessary to change to the highest gear to achieve maximum slack whilst working on the cable.

I only learn this sort of thing by doing it, and many a time I've started and then had to come on here for help to finish a little adjustment! There are lots on here who are very knowledgeable.... and I'm gradually improving. Just ask and someone will have some advice

 

[raleighnut]

I can't recall if I did that when I first removed the clamp if am honest.

I suppose this shows the pitfalls of trying something you have never done before, and when you don't understand the workings of the mechanisms involved. I recall the Youtube videos saying you should change to the highest gear / smallest cog, but don't recall any explanation for this, and I may well have forgotten about it. Having played around with the cable and felt the difference in tension when the shifter is moved either way, i now understand why it is necessary to change to the highest gear to achieve maximum slack whilst working on the cable.

Having said all that, would it make any difference because after reconnecting the cable I did move the shifter to the position that would select the highest gear, if it was working correctly, and there was a lot more slack when I disconnected it again? Perhaps my naivety is showing again, buying that big blue book might be a good idea

It's an easy mistake to make, some peple think "well I'll just shift the lever to that before I hook it back up" but the ratchet in the brifter won't work without cable tension.
As for the 'blue book' there is a lot to be said for learning by mistakes and it's not like you've broken anything,

Looking at your last picture, your cable run doesn't appear correct - it should be in the guide slots under the part of the dérailleur that the cable is against where the kink is. Here's how it should be...
View attachment 337545

Nice picture of the cable routing, have you thought about using 'anti-fray' end caps.

 

[Jenkins]

Nice picture of the cable routing, have you thought about using 'anti-fray' end caps.

It got "removed" - pulled too hard with pliers in an effort to keep the cable tight - when I was messing with the cabling last year I'd deal with it if I could be bothered.

 

[raleighnut]

It got "removed" - pulled too hard with pliers in an effort to keep the cable tight - when I was messing with the cabling last year I'd deal with it if I could be bothered.

http://www.google.co.uk/url?sa=t&rc...-caps/&usg=AFQjCNEy34lJiC9MvpVbspf89IM4AmI0BA

 

[Roadhump]

The advice about learning by doing things and making mistakes is very true, there is no substitute for learning by bitter experience imho, an analogy could go something along the lines of you only learn to swim when you jump in the water....only problem is that the time it takes to learn the lessons means the bike is unavailable for use for longer periods.....perhaps I need to buy another bike then.....so, how can I sell this to my lovely wife?

 

[growingvegetables]

The advice about learning by doing things and making mistakes is very true, there is no substitute for learning by bitter experience imho,..........

... Not sure how to say this, so I'll whisper. [There is actualy a substitute - learning from other people's bitter experience.]

Seriously - I don't suppose I'm the only one watching the thread ... and learning! So thank you. Not much consolation .

 

[growingvegetables]

Hmm - and after the cheeky bit. Just a fwiw from somebody learning from the thread.

Years ago, I threaded the cable adjuster on one of the kids' bikes. Cheap-o, cheese-o components, not manufactured to be of use if the cable was under tension. Lesson learned - probably unnecessary for the vast majority of bikes, but learned nevertheless. Ever since, I flick the shift so the cable is slack before using the cable adjuster.