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problem with blocked hole for front derailleur cable in carbon frame


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#1 BIANCHI_EURO

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Posted 23 March 2011 - 03:08 AM

Hi,

 

I have a major problem with the very small hole in my frame that's located behind the seat tube. This is the hole through which the front derailleur cable goes to the underside of the frame.

 

The old cable broke at the location right at the dura ace shifter. It turned out that the cable was pretty difficult to remove from the frame. I used a wrench to gently pull it out. I wanted to clean out the dirt and insert the new cable, but no matter what I try, nothing gets through the hole anymore. Even penetrating oil doesn't get through (tried an overnight period and from both sides). The penetrating oil just stays in the hole, the level doesn't get any lower, so it doesn't dissapear in the bike frame either.

 

My questions are:

1. Did anybody else experience similar problems?

2. Does anybody have a clue what to do now?

3. Is there a little tiny tube thorough the frame connecting the upper- and the lower hole or (I don't think so) does it run freely through the frame tubes?

4. Will this narrow tube be in a straight line or will it be bended. (If it's in a straight line maybe I could carefully use a hand drill to clear whatever is in the hole out)?

 

Hoping for some good advice, I remain.

 

 


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#2 swampy1970

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Posted 23 March 2011 - 05:43 AM

Unfortunately, my crystal ball can't really make out what frame you have or where exactly this behind the seatpost hole is. Nor can it give me a link to the website of the manufacturer to see if there's been 1,234,567 people who have suffered the same fate....

 

With all those factors taken into account, I reckon a 1" diameter drill should provide sufficient clearence for the front mech shifter cable to move freely. That and some cellotape - because cellotape always makes it better.

 

Any basic information like specific make, model, year of manufacture etc etc would be really really helpful.



#3 BIANCHI_EURO

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Posted 23 March 2011 - 07:53 AM

I don't see the relevance of the information, because there's many frames with this type of construction with the mini hole richt behind the seat tube for guidance of the front derailleur cable. But here are the specs:

 

Frame: Bianchi XL carbon (Alesio pro bicycle team le)

Tube set: Deda carbon

Gruppo: Dura Ace 7800 group (also original Dura Ace cables)

 

The bike is kept in supre condition and always cycled grandisimo!

 

 


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#4 MMMhills

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Posted 23 March 2011 - 08:37 AM

If you can put the cable through the hole from both the top and bottom than neither is plugged.  You just need to be patient and try try try until you finally get it.  Try to use a dab of superglue on the cable end so that it does not unravel on you (wait for it to dry before putting it in the frame).

 

I have the small tube that came with my frame for the initial installation and use it as a guide.  Of course you need to use the old cable to get it back through and that is not an option for you.

 

Good luck.



#5 MMMhills

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Posted 23 March 2011 - 08:38 AM

you could also call a Bianchi dealer and ask them for advise.



#6 tafi

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Posted 23 March 2011 - 02:23 PM

I'm not quite sure what the significance of the oil is.  Surface tension could be holding it in place.  In any case, a hole in a carbon frame is no place for oil.

 

As long as you can thread a new cable through all will be well.

It may be that the hole on each side of the frame is joined by a guide (tube), in which case just push the new cable through and you should push out any debris that is plugging the hole.

If the the holes are not joined by a guide then (as MMMhills suggested) you might need to stab around a bit with the cable.  You should be able to tell by feel which is the case here.

 

Short of these things, no-one here can see your problem so taking it to a mechanic is a good idea also.

 



#7 swampy1970

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Posted 23 March 2011 - 02:55 PM

If you don't see the relevance of helping us understand what you're trying to fix then I don't see the point in trying to help.

 

Good luck unblocking your hole.



#8 dhk2

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Posted 23 March 2011 - 04:44 PM

bianchi, believe I know what you're talking about.  The holes are in the "monobox" fitting, right in back of the seattube.  It's possible some people here aren't familar with the monobox construction.  On my frame, the monobox fitting joins a CF rear section to an aluminum main triangle; the box design allows for plenty of bond area with the CF rear plug.   The holes are positioned carefully to allow the FD cable to come up though the mono fitting in line with the FD.   On my (custom) frame, there is no guide tube inside; you have to "fish" the cable through. 

 

I'd just go ahead and clean the holes out with a cable, awl or drill bit of matching size (1/16 or 3/32's?).  Not sure how the holes got plugged, but they shouldn't be too hard to clear.....it's got to be road grit or sand.      



#9 alfeng

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Posted 24 March 2011 - 05:30 AM



 

Originally Posted by BIANCHI_EURO View Post

I have a major problem with the very small hole in my frame that's located behind the seat tube. This is the hole through which the front derailleur cable goes to the underside of the frame.

 

The old cable broke at the location right at the dura ace shifter. It turned out that the cable was pretty difficult to remove from the frame. I used a wrench to gently pull it out. I wanted to clean out the dirt and insert the new cable, but no matter what I try, nothing gets through the hole anymore. Even penetrating oil doesn't get through (tried an overnight period and from both sides). The penetrating oil just stays in the hole, the level doesn't get any lower, so it doesn't dissapear in the bike frame either.

 

My questions are:

1. Did anybody else experience similar problems?

2. Does anybody have a clue what to do now?

3. Is there a little tiny tube thorough the frame connecting the upper- and the lower hole or (I don't think so) does it run freely through the frame tubes?

4. Will this narrow tube be in a straight line or will it be bended. (If it's in a straight line maybe I could carefully use a hand drill to clear whatever is in the hole out)?

 

Hoping for some good advice, I remain.

 

 


Can you push a 14g-or-15g spoke (or, equivalent) through the hole FROM EITHER END?
 

 



#10 BIANCHI_EURO

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Posted 24 March 2011 - 10:11 AM

Maybe I don't make myself clear in the English language very well. I am not a native English speaker. But the hole is blocked, I cannot put anything through. The oil is necessary because you'll need to lubricate the cable anyway. I tried to use some extra oil in order to clean the dirt out. I assumed that there was a tube inside so the oil wouldn't enter the frame anyway. Probably this assumption was correct, because even the penetrating oil didn't flow away. I built up this bike myself and I remember from the construction phase that it's not just a drilled hole, but it looked like a tube entrance. I have to be sure that it's not just two tube entrances which are not connected with each other on both top and bottom side of the frame. They have to be connected (in other words a tube). Otherwise I ruine from inside out the entrance on the other side.

 

DHK2 understands exactly what I mean and probably he/she is able to give a better description/explanation of the problem:

[quote=dhk2]

bianchi, believe I know what you're talking about.  The holes are in the "monobox" fitting, right in back of the seattube (exactly DHK2!!).  It's possible some people here aren't familar with the monobox construction.  On my frame, the monobox fitting joins a CF rear section to an aluminum main triangle; the box design allows for plenty of bond area with the CF rear plug.   The holes are positioned carefully to allow the FD cable to come up though the mono fitting in line with the FD.   On my (custom) frame, there is no guide tube inside; you have to "fish" the cable through. 

[/quote=DHK2]

 

I think the spoke trick from "alfeng" is a good one. But when I push with a metal needle, it's as if I'm striking something hard. I have to be exremely cautious because if there is no tube in there, or the tube inside the frame is bended, than I might ruine the little tube inside the frame.


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#11 BIANCHI_EURO

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Posted 24 March 2011 - 11:59 AM

I asked Bianchi about this. At the moment I am awaiting their reply. Maybe it's a good idea to ask Deda tubes, or try to see some Deda tubes at the local custom factory in order to see whther thre is a mini guidance tube inside those monobox CF tubes.


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#12 alfeng

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Posted 24 March 2011 - 07:34 PM

FOR YOUR CONSIDERATION:


Is it at all possible that when you removed the cable & housing that one-or-both of the housing's end caps may have been left in the recesses of either end of the frame's openings?
 

  • If so, FWIW, that's another reason that I don't like the parallel stranded cable housing which Shimano & Campagnolo supply with their cable sets.

 

 



#13 BIANCHI_EURO

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Posted 09 April 2011 - 11:49 AM

No the endcap is right here on my desk. Luckily I saved it, otherwise I might even have started to wonder. My thoughts go to maybe a strand of the steel cable which got stuck? Maybe for some reason the little tube through the monobox is damaged (hard to believe since nothing strange happened before the cable snapped)... Strange problem.

 

I am still waiting for Bianchi's technical department in Italia to reply (this bike is handmade over there). I hope they have some experience with this problem.


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#14 waxbytes

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Posted 11 April 2011 - 06:36 PM

Do you have access to a compressor? Try blowing out the blockage with compressed air?

Wear eye protection if you try this because this is the type of situation that sometimes sends crud flying back at the user.



#15 tafi

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Posted 11 April 2011 - 08:52 PM

 

Maybe I don't make myself clear in the English language very well. I am not a native English speaker. But the hole is blocked, I cannot put anything through.

You are making yourself perfectly clear.  No-one who has responded so far does not understand what the basic problem is.

 

The oil is necessary because you'll need to lubricate the cable anyway.

The hole through the "monobox" is a clearance hole and no lubrication should necessary at this point.  It is up to you, what you do, but, putting oil around this point of the frame just attracts dirt.

 

I assumed that there was a tube inside so the oil wouldn't enter the frame anyway. Probably this assumption was correct, because even the penetrating oil didn't flow away.

The hole for the cable is small and fluids can be held in place in such a hole by their own surface tension.  The fact that some oil stayed in the hole is not necessarily proof of a blockage.

 

I have to be sure that it's not just two tube entrances which are not connected with each other on both top and bottom side of the frame. They have to be connected (in other words a tube). Otherwise I ruine from inside out the entrance on the other side.

I think you mean that you are sure that the holes on each side of the "monobox" are joined by a guide.  You need to be sure about this, because, contrary to what you think, it is not necessary for the holes to be connected with a guide.  Many frames actually don't have a guide, as DHK2 suggested:

 

Quote: By DHK2
On my (custom) frame, there is no guide tube inside; you have to "fish" the cable through.

In such cases the frame may have come with a temporary plastic tube in the frame to assist cable installation or changing cables.  You can find out with the spoke method Alfeng suggested.  Put the spoke in one side and wiggle it around.  If there is a guide you would not be able to wiggle the spoke around much.

 

I think the spoke trick from "alfeng" is a good one. But when I push with a metal needle, it's as if I'm striking something hard.

Yes it is a good one but you need to be sure of the conclusions you draw from it.  Are you sure you're striking an obstruction? Or are you just hitting the other side of the "monobox" (from the inside)?  You can check this by measuring how far you can poke the needle through and comparing that to the measured depth of the "monobox".

 

I have to be exremely cautious because if there is no tube in there, or the tube inside the frame is bended, than I might ruine the little tube inside the frame.

It is true that being cautious will help prevent damaging the frame, but, I think your cautiousness may also be preventing you from finding out what is going on (and possibly fixing the problem).  If there is a guide then it will be integral with the carbon of the frame and therefore should be quite strong.  It should have started life straight for a straight cable run and if it is solidly mounted at each end it should stay that way.  If there is no guide then the worst you will do is hit the wall on the other side (hardly catastrophic - possibly you've already done this).

 

In light of this and the fact that it has now been three weeks since you reported the problem, it might be time to just take the frame to a bike shop and get a mechanic to look at it.  The thoughts of everyone else here is about all you will get without actually seeing the frame.



#16 BIANCHI_EURO

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Posted 13 April 2011 - 08:28 AM

Thanks again for the answers.

 

Yes, three weeks already... Before taking action, I am still awaiting the answer from the Bianchi factory. I want to be 100% certain about what I am doing.

 

With the oil you're right. But I was worried about the breaking cable and I thought that mabe it needed some lubrication in order to prevent it from breaking again. But now I am sure yu're right. From other cyclists I understood that there is a liner inside the hole which functions as a slide bearing. Probably this liner is damaged and caused my cable to break. By taking away the broken cable the damaged liner got jammed in the hole and now it's impossible to put through the new front derailleur cable.

 

If the above is really the reality, then the old slide bearing will have to be replaced by a new one. I 'll need a new "slide bearing tube" and an instruction sheet (or whatever) from Bianchi in order to know how to mount a new ("slide bearing") tube.

 

I want to give Bianchi some more time to come up with a sollution. Porbably I am one of the first cyclists with this problem, with many more to follow. After a few years of fanatic cycling the tube will collapse and you've got a major monobox problem .


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#17 dhk2

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Posted 14 April 2011 - 07:45 PM

Bianchi, I'm surprised that your frame has a "guide tube" inside.  It's probably a plastic tube that's glued in place or perhaps located with bushings.  In my opinion, it's not needed and risks the problem you've experienced.  I replaced my FD cable once (at 18K miles), and it only took a few tries to poke the cable from the bottom through the top hole in the monobox. 

 

Your patience while waiting for the factory guidance is admirable.  But If it were my frame, believe I would have clear the holes with a spoke or drill bit by now rather than have the bike sitting for three weeks.  Wouldn't be surprised if the Bianchi rep tells you to do just that.  Good luck! 



#18 BIANCHI_EURO

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Posted 19 April 2011 - 03:59 AM


 

Originally Posted by dhk2 View Post
Your patience while waiting for the factory guidance is admirable.


 


Yes... that's what I think too . "Bianchi" waiting for Bianchi... for almost a month

 

But what else can I do? If I poke through with a spoke and later find out that I made things even worse, than I would regret. At the same time I really feel that poking through is not going to work since it is not just debris in the hole. There's something hard in there blocking tha way through and therefore I find the "sliding tube bearing theory" very much believable.


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#19 alfeng

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Posted 19 April 2011 - 08:26 AM


 

Originally Posted by BIANCHI_EURO View Post

The old cable broke at the location right at the dura ace shifter. It turned out that the cable was pretty difficult to remove from the frame. I used a wrench to gently pull it out. I wanted to clean out the dirt and insert the new cable, but no matter what I try, nothing gets through the hole anymore.

 


BTW.  It may be opening-a-can-of-worms, but have you looked at how the OTHER derailleur cable feeds through the frame?

 

AND, who did the initial assembly of the bike?
 

 

Is THAT person-or-bike-shop in the same country that you live in (i.e., local to you OR within 100km)?

 

 

  



#20 BIANCHI_EURO

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Posted 10 June 2011 - 01:45 PM

Hi again,

The solution:
Yep.. a lot of people are going to run in a lot of trouble in the near future with their monobox frames. Bianchi didn't answer until I became angry (after a month). And then they suggested my own initial suggestion when I wrote my service request a month ago to Bianchi (I suggested to use a drill to get through).

 

The lack of any usable advice and the fear of Bianchi to be held liable for the problem has irritated me very much. According to me these people don't have a technical education. It's just a sales organisation with production in Taiwan, according to me. On the frame it says that the frame is "handmade in Italia". I always found it hard to believe that this frame is handmade because the construction is impossible to be made by hand. And how can itr be handmade by Italians if they can't even tel me whether the monobox drill hole is bended or straight. You guessed it... this was the last Bianchi of Bianchi_Euro... Unhappy with the service if any service at all.

I found out myself:...
1. yes!! the hole is a straight line through the monobox(!in my frame!).
2. it turned out to be dirt in the hole.
3. use a handdrill to get it out.
4. in my frame there's no liner in the hole that can be cracked, the inside of the drilling hole almost looked like solid carbon fibre (no sliding bearing here).

Thank you for all your messages. Hopefully this update with my experiences will help other people to solve their problem. I hope they provide their contribution as well on this thread.


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