# TCR Advanced cable routing & cable friction



## tom_h (May 6, 2008)

I'm a long time Specialized S-Works Tarmac rider, but I am thinking about a TCR Advanced frameset next year, that I would build up.

I'm unable to find any detailed technical info on the Giant website, concerning the internal cables.

Specifically - do the hidden shift & brake cables actually slide inside a sheaths, casings, or housings, once the cables enter the frame? 

I am concerned about the cable friction.

The Specialized frames use hidden sheaths only for routing and snaking the cables through the frames. Once cables are routed inside the frame, those mini-sheaths are removed and the cable itself is free-floating -- no added friction.

How does Giant do the cables?


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## Ventruck (Mar 9, 2009)

Not sure if it varies or if there's even a strict way to do it. I've read most do without sheaths/liners. If you buy it brand new there would be some in there for ease of installation like the Specialized frames you mentioned.

My LBS kept the liners (or perhaps added their own) in my 2015 Advanced for the shift cables. Literally straight piece from headtube to rear dropout at the exit/entry ports for the RD, and you'd evidently see the liners running past the BB shell. So far in over a month it's been problem-free and smooth. Technically would be better as it's "completely sealed", and there's no tight bends to make it an issue just as long as you don't wrinkle or crease the liner.

I'm not sure if you can get away with that for the 2016 version. Depends if the guides at the BB shell could accommodate it I guess.


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## izza (Jul 25, 2012)

Ian 2015 models there is no sheaths or internal casings. The cables are free floating.


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## MMsRepBike (Apr 1, 2014)

The only bikes I know of that would use an inner lining are those that have the cable run around bends where they would eat into the carbon. As in bikes that have the cables all enter in the top of the top tube.

No traditionally built internal routed frame uses internal sheething that I'm aware of. The Tarmac and TCR are just like everything else.


You should know though, being a long time Tarmac user, that the Tarmac actually requires a sheath in the top tube to run over the cable. This sheath has rubber bumpers attached to it and is the tool used to stop/quiet the cable rattling and making noise in the top tube.


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## tom_h (May 6, 2008)

MMsRepBike said:


> .. You should know though, being a long time Tarmac user, that the Tarmac actually requires a sheath in the top tube to run over the cable. This sheath has rubber bumpers attached to it and is the tool used to stop/quiet the cable rattling and making noise in the top tube.


But I believe that sheath is a "static" guide sheath used during cable installation.
ie the inner cable does Not slide within that mini-sheath -- so no added cable friction.


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## tom_h (May 6, 2008)

izza said:


> In 2015 models there is no sheaths or internal casings. The cables are free floating.


Couple days ago a mechanic should me what he claimed was the sheath inside the downtube, from a TCR. That sheath had an end ferrule, which supposedly was static & fixed in place, where the shift cable enters it. Therefore the shift cable had to be sliding within that mini-sheath and adding friction.
Possibly either the mechanic or myself misunderstood each other.
But that's what concerns me on the TCR -- possibility of cable friction on a mostly full-length sheath.
if only I could get an install manual, which should decisively convince me one way or the other.
Unfortunately, it appears Giant does not have any install manuals on their web, unlike Specialized.


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## MMsRepBike (Apr 1, 2014)

tom_h said:


> But I believe that sheath is a "static" guide sheath used during cable installation.
> ie the inner cable does Not slide within that mini-sheath -- so no added cable friction.











Note the tech tip.


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## tom_h (May 6, 2008)

MMsRepBike said:


> Note the tech tip.


Yes .. but it says,
_"route the cable through the sheath (F) and through the brake ICR stop hole in the top tube,* then remove the sheath*._"

Leaving that short section of sheath (F) is optional .. and in any event, the cable itself does Not slide relative to the sheath .. therefore no added friction.


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