# Can cable rub inside top tube ?



## tunganh.46 (Aug 13, 2014)

Im setting up the rear brake cable on my New Tarmac and found that i dont have the "F" sheath running along with cable inside toptube. I only have 2 "A" sheaths to install.







Is cable going to rub my frame inside when i brake or "F" sheath is only for prevent rattle?


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## 1Butcher (Mar 15, 2011)

To prevent rattles.


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## tunganh.46 (Aug 13, 2014)

1Butcher said:


> To prevent rattles.


So without it, can the bare inside cable damage my frame? I can hear some rubbing sound when braking but no rattle sound when riding ?


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## 1Butcher (Mar 15, 2011)

I guess it could, but the cable should not be hitting the inside of the tube. It will run close to it and when it vibrates, it will hit the inside tube.

But of course, maybe yours is different. Any sleeve will work. I just when into my LBS and asked for some. They gave it to me, no cost [including the rubber donuts]. The first internal cable routing bikes did not have this recommendation. It was a fix to prevent noises from the cable.


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## NZPeterG (May 21, 2011)

tunganh.46 said:


> Im setting up the rear brake cable on my New Tarmac and found that i dont have the "F" sheath running along with cable inside toptube. I only have 2 "A" sheaths to install.
> View attachment 301454
> 
> Is cable going to rub my frame inside when i brake or "F" sheath is only for prevent rattle?


Hi the "F" sheath is to cut down on cable nosie over bumps.
Here is the low down start watch from 03:08 

[video]http://servicevideos.specialized.com/video/25739509[/video]

All the best and have fun riding or new bike 

Kiwi Pete...


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## tunganh.46 (Aug 13, 2014)

Much appreciated for your reply. I have just customed a sheath for that.
I have another concern about the manual. It says i dont need short sheath after Housing ferrule, so i dont add sheath. May the cable rub the downtube?
Here is the manual, at *fig.3*
View attachment 301471


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## Dunbar (Aug 8, 2010)

tunganh.46 said:


> It says i dont need short sheath after Housing ferrule, so i dont add sheath. May the cable rub the downtube?


Some people use a sheath for weather proofing (to keep water out.) The derailleur cables can't rub the down tube if you install them properly.


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