Bianchi Xl Carbon / Dura Ace/ Building Up

[BIANCHI_EURO]

Hi,

I built up a Bainchi XL carbon frame with a Dura Ace 7800 group. The front derailleur happens to be shifting quite heavilly causing a bad sound and even worse feeling when shifting from 53 towards 39.

The probable cause of the bad shifting is probably the tiny hole in the frame located in the "mono block" chain stay part (right behind the seat tube). The front derailleur cable has to travel through this tiny hole in the frame. I think this causes too much friction when releasing the cable. This causes heavy load on the shifting lever at the handle bar and then at once a sudden jump (both at the lever and at the front derailleur).

I tried to lubricate the hole with teflon oil spray. But this isn't helping enough. I wonder if anybody knows about a specific trick for the Bianchi XL frame to get rid of this problem?

Thx, Frank.

 

[daveornee]

Hi,

I built up a Bainchi XL carbon frame with a Dura Ace 7800 group. The front derailleur happens to be shifting quite heavilly causing a bad sound and even worse feeling when shifting from 53 towards 39.

The probable cause of the bad shifting is probably the tiny hole in the frame located in the "mono block" chain stay part (right behind the seat tube). The front derailleur cable has to travel through this tiny hole in the frame. I think this causes too much friction when releasing the cable. This causes heavy load on the shifting lever at the handle bar and then at once a sudden jump (both at the lever and at the front derailleur).

I tried to lubricate the hole with teflon oil spray. But this isn't helping enough. I wonder if anybody knows about a specific trick for the Bianchi XL frame to get rid of this problem?

Thx, Frank.

I don't know what the hole looks like or that other purpose the material with that hole in it serves.
Have you tried removing the cable and putting a teflon liner through the hole or at least coating the cable with Dupont Teflon Grease where it passes through the hole?
Have you considered enlarging the hole and making sure the bore is smooth and the ingress and egress points rounded?
Do you have a picture or a link to a picture that shows the area of interest?

 

[BIANCHI_EURO]

Yes, it 'll be hard to get any info from this forum about this subject since it's a type related problem. There is a picture of the hole on the following
(great) page:

Once on the page:
- click on "tutte" (left side of page)
- click on the arrow in front of "prova"
- click on the arrow in front of "prove"
- click on the arrow in front of "Bianchi Xl carbon, ambiziosa senza limiti"

(Don't mistakenly click on the Bianchi XL mtb page)

- then click the third page called "componenti"
- now take a look at the second picture
- if you look carefully you 'll see the front derailleur cable behind the seat
tube dissappearing in a tiny hole in the composite frame

here goes the link to the page:

http://www.ciclismonline.it/edisport/ciclismo/notizie.nsf/

Regards, Frank.

 

[dhk]

Yes, it 'll be hard to get any info from this forum about this subject since it's a type related problem. There is a picture of the hole on the following
(great) page:

Once on the page:
- click on "tutte" (left side of page)
- click on the arrow in front of "prova"
- click on the arrow in front of "prove"
- click on the arrow in front of "Bianchi Xl carbon, ambiziosa senza limiti"

(Don't mistakenly click on the Bianchi XL mtb page)

- then click the third page called "componenti"
- now take a look at the second picture
- if you look carefully you 'll see the front derailleur cable behind the seat
tube dissappearing in a tiny hole in the composite frame

here goes the link to the page:

http://www.ciclismonline.it/edisport/ciclismo/notizie.nsf/

Regards, Frank.

I have the similar hole in an aluminum/CF monobox SANO custom frame. You could check for any friction in the cable simply by disconnecting it from the FD and determining if it moves freely.

My experience says the more likely causes would be incorrect height of the FD over the chainring, or incorrect alignment of the cage. The outside of the cage needs to be exactly parallel with the chainrings so that the cages first push on the chain in just the right place; otherwise you'll get a hard and noisy shift.

 

[Feideaux]

I have the similar hole in an aluminum/CF monobox SANO custom frame. You could check for any friction in the cable simply by disconnecting it from the FD and determining if it moves freely.

My experience says the more likely causes would be incorrect height of the FD over the chainring, or incorrect alignment of the cage. The outside of the cage needs to be exactly parallel with the chainrings so that the cages first push on the chain in just the right place; otherwise you'll get a hard and noisy shift.

Have to agree, my XL carbon shifts excellently, and that's with three year old Ultegra. Try another mechanic, is my advice.

F.

 

[BIANCHI_EURO]

Hi,

I think David is right. I tried to put the front derailleur in several different positions today (adjusting the tension lock ring on the seat tube) and sometimes the derailleur is almost shifting okay. But still that last final little bit is missing...

The height of the derailleur can't be the problem (1-2 mm above the 53). So I altered the alignment slightly which had a lot of effect. Apperently the alignment of the FD is very critical and difficult, right? A milimeter mistake and the result is horrible shifting... Also I varried the tension on the FD cable. I compared the Shimano stuff with my Campa equipment.

The hole in the frame is not the cause. Tomorrow I am going to try once more (I was a little exhausted today after the training). Maybe there is a problem with the FD, since I received it in an opened box.

I'll let u know what happened.

Thx for your good advice, Frank.

 

[dhk]

Hi,

I think David is right. I tried to put the front derailleur in several different positions today (adjusting the tension lock ring on the seat tube) and sometimes the derailleur is almost shifting okay. But still that last final little bit is missing...

The height of the derailleur can't be the problem (1-2 mm above the 53). So I altered the alignment slightly which had a lot of effect. Apperently the alignment of the FD is very critical and difficult, right? A milimeter mistake and the result is horrible shifting... Also I varried the tension on the FD cable. I compared the Shimano stuff with my Campa equipment.

The hole in the frame is not the cause. Tomorrow I am going to try once more (I was a little exhausted today after the training). Maybe there is a problem with the FD, since I received it in an opened box.

I'll let u know what happened.

Thx for your good advice, Frank.

Yes, cage alignment vs. the chainring plane is very critical, since it determines where the derailleur first makes contact with the chain. The cage needs to "pick up" the chain before it engages the chainring tooth, otherwise you're trying to push the chain straight off the chainwheel when you shift. Setting the outer cage plate exactly parallel with the big ring should do the trick.

It's possible your FD has a slightly bent cage. If the cage is bent, even a little, achieving proper alignment will be impossible. Let us know about your progress.

 

[BIANCHI_EURO]

Hello,

Well here the outcome. I checked some other Dura Ace mounted bikes and saw that compared to Campa the FD is slightly turned inward (seen towards the front side). Indeed the front point and read point of the FD have to be placed exactly above the chainwheel (the FD blade is somewhat curved, right?).

Shifting goes not as perfect as with Campa. I get the feeling of releasing something when going to the 39. Of course I AM releasing something, but with Campa the feeling is more smooth. Checking with the other bikes I realized it can't get better than it is now.

I have been busy test riding the bike for a couple of days in the Ardennes here. Great bike. Very fast uphill and on flat area's. Only trouble is that the carbon seatpost (Dedacciai Black Stick) remains sinking into the seat tube of the frame. I already changed the seat post clamp for a special carbon seatpost designed clamp. I didn't help. Well that's the final straw...

Thanks a lot for the great advice on the FD! I was looking in the wrong direction.