Shifter cable nightmare

ED E

Hi all,

Hopefully somebody can shed light on what's going wrong here. The pictures below are from the first failure. That was the 5th of August. The end of the RD cable sheared off into the Shimano shifter. Man was that a b1tch to remove. I replaced the cable, checked the outer, it looked fine and the cable fed ok so I left it.

Then about a month or so later it happened again, exact same place. Well f'ck I thought, the outer musn't have been ok. Replaced cable and outer. Grand.

Today it happened for the 3rd time in 4 months. Same place. Felt a little weird so when I arrived at work I extended it to inspect it and SNAP(followed by a string of profanities).

Anyone know whats going wrong here? I cycle to college then work and home 6 days a week. Cant afford to have it breaking down(thus why I recently got armadillos to sort the puncture problem). Do I need a better shifter, are these Shimanos sh1t? They're Tiagra's.

Any help appreciated,
Thanks,
ED E.

smacl

You've probably checked these but..

Where the cable is snapped, i.e. very close to the shifter end, suggests either the cable hasn't been fed all the way into the shifter, or the outer isn't all the way in to the shifter on the other side.

Are you sure you're using the right type of cable? Gear cables are different to brake cables, and shimano cables are different to campag.

I don't know tiagra, but on the veloce shifters I'm using, you have different cable and outer routes based on whether the outer follows the bars, or leaves the bar at the shifter. Picking the wrong route would put pressure on the cable pretty much where you're getting the break.

Pinch Flat

Would agree, looks like there's friction from rubbing that's weakening the cable. Have a look at the shimano tech docs and follow the steps to ensure it's routed probably and with the correct cable, heads are different on some cables.

lescol

Also check the opening of the outer cable to see if a burr has been left from cutting it.

victorcarrera

lescol wrote: »

Also check the opening of the outer cable to see if a burr has been left from cutting it.

+1 and check that the outer cable is long enough so that there is no sharp bend where it enters the shifter when the handlebars are straight.
Edit: That looks like a metal cable end in the photo. They have sharp edges so I would change those for plastic ones too.

ED E

smacl wrote: »

You've probably checked these but..

Where the cable is snapped, i.e. very close to the shifter end, suggests either the cable hasn't been fed all the way into the shifter, or the outer isn't all the way in to the shifter on the other side.

Are you sure you're using the right type of cable? Gear cables are different to brake cables, and shimano cables are different to campag.

I don't know tiagra, but on the veloce shifters I'm using, you have different cable and outer routes based on whether the outer follows the bars, or leaves the bar at the shifter. Picking the wrong route would put pressure on the cable pretty much where you're getting the break.

Sounds possible, I'll check that.

Routing is the same way Raleigh did it.

Pinch Flat wrote: »

Would agree, looks like there's friction from rubbing that's weakening the cable. Have a look at the shimano tech docs and follow the steps to ensure it's routed probably and with the correct cable, heads are different on some cables.

First cable stock, second cable I didnt buy myself, but the heads matched. Third cable was what the lads downstairs in Cycleways handed me.

lescol wrote: »

Also check the opening of the outer cable to see if a burr has been left from cutting it.

There was a slight wear on the old cable. But that shouldnt be there on the new one. Havent had time to dismantle things yet

countrykid

did your shifter get a bang?
looks like a few scraps on it...
could have squeezed the mechs inside a bit causing the cable to chafe of outer shell and disintegrate slowly..

when they are working are the gear changes smooth? or tight and clumsy?

Lawr

I understand, too, that many of these 2009-2012 shifters did have a design that required the cable to take a rather drastic right angle turn. I had tiagra 9 speed shifters and, if I remember correctly, this did happen to me at least once. I think that it is also easy not to feed the cable in properly. It is difficult to see in there. I did it by feel. I moved the cable up and down the gears while pulling on the cable where it exits the shifter just to be sure it was well situated before putting the outer cable on and running it along the frame to the rear dérailleur. At the rear dérailleur, I ran the gears through their paces again just to be sure, before adjusting the rd and rolling merrily along. I doubt there is anything wrong with your shifters, though it does sound as if there might be a burr somewhere or a sharp edge.

ED E

Few more images(not that it helps hugely):

ED E

countrykid wrote: »

did your shifter get a bang?
looks like a few scraps on it...
could have squeezed the mechs inside a bit causing the cable to chafe of outer shell and disintegrate slowly..

when they are working are the gear changes smooth? or tight and clumsy?

Just a scrape off a wall, purely cosmetic.

Right before it fails it gets very rough. Usually Im on my way somewhere so I dont really have time to stop and investigate it just then.

Lawr wrote: »

I understand, too, that many of these 2009-2012 shifters did have a design that required the cable to take a rather drastic right angle turn. I had tiagra 9 speed shifters and, if I remember correctly, this did happen to me at least once. I think that it is also easy not to feed the cable in properly. It is difficult to see in there. I did it by feel. I moved the cable up and down the gears while pulling on the cable where it exits the shifter just to be sure it was well situated before putting the outer cable on and running it along the frame to the rear dérailleur. At the rear dérailleur, I ran the gears through their paces again just to be sure, before adjusting the rd and rolling merrily along. I doubt there is anything wrong with your shifters, though it does sound as if there might be a burr somewhere or a sharp edge.

Last time I fitted it I was really careful and it worked buttery smooth just after. The one thing I could find on it was that little arch in the plastic above the slot the cable end slips in to. Though I'm not sure if its manufactured that way or if its wear.

Not sure what caused it, cant find anything along the cables path that would have done it. All looks smooth. Might get onto Shimano and see what they say.

joxerjohn

Looks like a sharp edge where the cable outer goes into the shifter. 2nd picture down on the left. You could try smoothing this out with an awl tool or similar to get the rough edges off. I don't think you can replace it unfortunately.

Also the ferrule on the end of the cable outer should sit snuggly into the shifter at this point. looking at the photo i doubt that it would. Do you have a ferrule on this end of the outer ?

I had 9s tiagra shifter and they worked fine for me but your one does look damaged at that point.

ED E

Thats the same end, with ferrule off and on. Not sure if its actually sharp or thats just the pic, hard to get a proper look.

ED E

Shimano obviously say use their own outers, any significance in using another brand?

mp31

@OP - here's an idea.. why not use a bit of tippex on the new cable before it is installed and then after a few days you can see where it has been scraped off and by what.

joxerjohn

Other brands can have different cable size usually these gear cables are 5mm AFAIK. If it doesn't fit snuggly into the shifter then it doesnt protect the cable and that's where you'll get wear.

Looking at your pics again I think the ferrule you're using could be too big, it looks a bit scuffed as well on the end as if it is not fitting correctly. You should be able to check this by fitting the outer with the ferrule without any cable into the shifter. The same principles applies to the left hand shifter so have a look at this and see if there are any differences.

The gear cables I had were the Shimano SIS ones, but I have also used Clarks ones successfully with this type of shifters. Better again are the Jagwire cable sets.

I would take a trip to a good LBS and get a replacement cable outer with the correct ferrule for the job and a new Shimano compatible gear cable, make sure you cut off the correct end ! and that should sort it for you.

joxerjohn

Correction ! the diameter of a Shimano gear cable outer should be 4mm. If you used a brake cable outer it would be 5mm i.e it would be too big, and so wouldn't fit properly ! This is possibly the issue here I would say.

browsing

joxerjohn wrote: »

Correction ! the diameter of a Shimano gear cable outer should be 4mm. If you used a brake cable outer it would be 5mm i.e it would be too big, and so wouldn't fit properly ! This is possibly the issue here I would say.

I'd say that would cause problems alright. I think the OP has the correct diamter though as this is a "compressionless" outer. i.e. the wires are running parallel to the gear cable, unlike brake housing which is wound.

ED E

Checked the stock shimano outer against the replacement the LBS sold me, identical other than colour.

Will have to get a new cable tomorrow so I can get back on the road. Not solved yet but I need the bike.

browsing

ED E wrote: »

Checked the stock shimano outer against the replacement the LBS sold me, identical other than colour.

Will have to get a new cable tomorrow so I can get back on the road. Not solved yet but I need the bike.

In the mean time you could just adjust the limit screws on the deraileur so it's not in too hard a gear and use it as a single speed! Just change on the front ring if you're stuck going up a hill! It would get you out of a bind!

ED E

Bought a new cable, and ruined it in testing. Probably should have had the foresight to buy two.

Worked out what's happening. Everything is dandy when its in the normal 1-9 Positions. The problem is after 9, when you're in 9 and attempt to shift up(common enough when I'd be in traffic and not 100% what gear Im in). Pushing it slightly marks the cable. To test I pushed with more force than normal, big crimp in the cable.

It appears that something is doing a sort of racheting motion at left most side of the shifter, above the main barrel of gears. This is about where the cable is being crimped.

Bike is like 1.5yrs old or so so I doubt Wiggle would replace the shifter for me, will see what shimano say. Either way I think I'll take the luas till January.

browsing

Hi ED E,
If I was you I'd try to adjust the limit screws so that it's impossible to ratchet the mechanism as far past 9 as you are able to at the moment. This would stop you bending the end of the cable.

If you don't trust it until you have a few spare cables handy, you could adjust the limit screws even further so you can't get into 9! Then you definitely wouldn't be able to wreck the cable as you describe. You could just shift down on the front if you need an easier gear!

Whatever you feel like yourself but I'd personally want a quick interim fix to keep me on the bike.:)

ED E

Wiggle have washed their hands of it, supposedly its a component of the bike so its covered by a 1yr warranty not Shimanos 2yr warranty.

Time to replace it, any suggestions for places to look for em, Wiggle and CRC dont seem to stock em anymore. Will try a take down and see if I cant get her going myself before I order.

clog

Before changing the shifter check the indexing and rear mech limit screws. Yes the cable is crimping and ultimately breaking but you are pushing the lever past where its supposed to go.

Joff

I agree with browser and clog.....don't rush out and buy new shifters, it does sound like your RD is badly adjusted, allowing the shifter to go too far. Take it to a decent bike shop first, you mentioned cycleways-they should do this very quickly, unless you are happy adjusting it yourself. Hope that's all it is, good luck.

ED E

Im pretty confident its not that. Firstly, even if the RD goes to far the shifter shouldnt be snagging the cable, that'd be terrible design. Secondly, Ive just checked and the RD is still perfect from the last time it was set. Outer limiter locks the shifter right in line with the largest cog.

I took the little "window" off the the FD shifter and compared the two motions. Two differences. One, the ring behind the red indicator has a notch on it on the left shifter but present on the right(maybe by design) and two, the cable rises much more on the right shifter than it does on the left.

This guy had a similar issue:
http://www.bikeforums.net/showthread.php/110930-My-shifter-cables-break-to-often!
No solution listed.

From here:
http://forums.bicycling.com/topic/54635607129970344

This is not uncommon. It has happened to me.

What happens is that the cable inside the shifter frays where it "rolls" over the cylinder which translates the rotation provided by operating the shift levers to a straight-line pull of the cable going to the derailleur.

You can't see this inside the shifter body, so it can be insidious. I did have some warning, however, in the form of some shift hesitation for a few shifts before the cable cable actually broke. Don't know if you experienced that or not.

About the only thing you can do is to (1) Be particularly sensitive to any "hangups" or delays in shifting (this usually happens with the rear derailleur because so many more shifts are normally made there than in the front); (2) Change the shift cable periodically (once a year or so is probably a good rule of thumb if you ride a lot--especially if you shift the rear frequently while riding like I do).

And then THIS:


Have to go to work but I think either that roller is damaged or the cable is running the wrong side of it. More poking about to be done later, will report back.

browsing

Hi ED E,

Sounds like you've done a good bit of research on it! But still have no solution which is infuriating!
I wonder are you missing an "Outer casing holder spacer". It's in the shimano tech doc below.
http://techdocs.shimano.com/media/techdocs/content/cycle/SI/TIAGRA/SI_6UM0A/SI-6UM0A-001-00-Eng_v1_m56577569830746362.pdf

I don't see it in the pics you have above. Perhaps whats happening is that the end of outer can move around a little so it can move into a position where it shouldn't be able to which causes the cable to run against the edge of the shifter moulding as it enters the shifter.

Perhaps if you take out the rear cable, you'll see this spacer in the LH shifter?!? Then you could put it in the RH shifter to do you for a while.
I dunno if this is the answer, just a stab in the dark. The spacer might be there, I just can't see it in the pics.

Also, I'd be surprised shimano was designed in a way that over ratcheting destroyed the cable.
Since you say destroyed the most recent cable just in the testing phase (I presume not while riding?), would you consider decommissioning 9th gear while you test for a while? If you can ride a month or so you'd know that overratcheting past 9 is definitely the problem. Personally I'd suspect it's not the problem as I'd say this is done often enough.

Best of luck with it anyway, sounds pretty annoying!

coastwatch

Just looking at your photos, is the cable entry hole on the shifter directly in line with the groove in the roller or has it become slightly offset for some reason?

ED E

browsing wrote: »

Hi ED E,

Sounds like you've done a good bit of research on it! But still have no solution which is infuriating!
I wonder are you missing an "Outer casing holder spacer". It's in the shimano tech doc below.
http://techdocs.shimano.com/media/techdocs/content/cycle/SI/TIAGRA/SI_6UM0A/SI-6UM0A-001-00-Eng_v1_m56577569830746362.pdf

I don't see it in the pics you have above. Perhaps whats happening is that the end of outer can move around a little so it can move into a position where it shouldn't be able to which causes the cable to run against the edge of the shifter moulding as it enters the shifter.

Perhaps if you take out the rear cable, you'll see this spacer in the LH shifter?!? Then you could put it in the RH shifter to do you for a while.
I dunno if this is the answer, just a stab in the dark. The spacer might be there, I just can't see it in the pics.

Also, I'd be surprised shimano was designed in a way that over ratcheting destroyed the cable.
Since you say destroyed the most recent cable just in the testing phase (I presume not while riding?), would you consider decommissioning 9th gear while you test for a while? If you can ride a month or so you'd know that overratcheting past 9 is definitely the problem. Personally I'd suspect it's not the problem as I'd say this is done often enough.

Good suggestion, but Ive the version with no adjusters there.

Agreed, poor design and shimano arent two phrases I'd put together normally.

coastwatch wrote: »

Just looking at your photos, is the cable entry hole on the shifter directly in line with the groove in the roller or has it become slightly offset for some reason?

In line. And I found it, next post will explain.



Thanks for the input both of you

ED E

So, I wanted to avoid taking them down too much if possible, but it turns out you can pull the cap off if you remove a little plastic cover to allow you remove the nut. And now I know what's happening. And most likely why its happening.

Used the DSLR this time, the GS3 wasnt going to cut it. (click for high res, explanation at bottom)











As you can see, its getting very clearly crushed. If you look at the first image with a red arrow, thats where it seems to have broken. That should be limiting the cog that retains the cable, but it appears bent and possibly snapped. Its not rough edged but I assume thats due to being worn down since it snapped off. Cheapo metal, the reason its not Ultegra it seems. If you look at the later pic from the LH shifter it makes a straight contact before the cable gets caught between the cog and arm above(which has a plastic cover on that side).

It seems to be part of the frame that broke. So cant replace just it even if I could get the springloaded parts back together after the takedown. Im tempted to put in some 2part resin to make up the space, but I know it wont last that long.

Least I know what happened. Mystery solved. Thanks for all the input guys.

Joff

Delighted you solved it, fair play for persevering with it, shame you have to buy new shifters though.
Probab a good time to upgrade to 105/Ultegra.

smacl

Great piece of investigative work and on the plus side you now know much more about servicing shifters even if you do have replace one. Good excuse for an upgrade.

browsing

Hi ED E,
Well done, seems like some good detective work there!
It seems odd that part that you point at has broken since it doesn't look like a piece has broken off. You can clearly see where it squeezes the cable alright. Those images are quite nice too.

It seems like you just need to put a limit on how much the system is allowed pull the cable into the system. You could try sticking a pit of plastic (or metal) to the lever iteslf where you have your first red arrow with superglue. You could just build it up a little bit in order to stop the mechanism pulling the cable in too much. A little bit of plastic superglued to the lever itself strategically should be able to increase this minimum distance just enough!

You might as well bite the bullet and take it apart, you've nothing to loose! Just make sure you're in no rush for the bike! I'd a stressful evening one night trying to get a 7speed rsx sti lever back together before a spin the next morning!

Also, with regard to resins etc, I came across this guy on youtube who was talking about building up plastic with superglue. You can put this filler stuff in which could do the thrick to build up the lever!:
https://www.youtube.com/watch?v=Hk1cojemglE
He's also a beast with autpomotive repair. Must get round to that....

He's an American, but I'm sure you could find a similar product here, could be just the ticket! You could then file down the plastic until you had the mechanism just right so it doesn't eat cables!

Best of luck anyway, I think finding the problem is the hardest part. Finding the solution is the fun!

browsing.

Lawr

In your last two photos, it looks as if the cable is being pressed flat by a dumbell-shaped rolling pin of sorts, and it appears that one end of the dumbell is on the same ramp that the cable is on, while the other is off the ramp. Should it be situated on the ramp as is the other side?

Joff

"Also, with regard to resins etc, I came across this guy on youtube who was talking about building up plastic with superglue. You can put this filler stuff in which could do the thrick to build up the lever!:"

If you go down this line you can mix talcum powder or chalk dust with super glue to make a very hard, and cheap, filler.

Keep us informed and good luck

browsing

Joff wrote: »

If you go down this line you can mix talcum powder or chalk dust with super glue to make a very hard, and cheap, filler.

Didn't know that but makes a lot of sense now I think about it. Must try that the next time I have to fix something plastic. I've had plenty of occasions over the years trying to get superglue to stick what I want!