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Since many here are considering or perhaps have just purchased a new Roubaix or Tarmac with hidden cable routing...I thought I would provide some simple tips I have learned. This can be used as a living thread for others to share their experience as well to help elevate working knowledge of threading cables through these great new bikes.
I will start by saying that anybody avoiding a hidden cable bike because they prefer the simplicity of an exposed cable frameset...shouldn't. Its super easy to set up the cables on the new bike. So want to mention this up front for anybody concerned about installing cables on the new bikes with hidden routing. Also cable drag is very low on my new build...bike upshifts solidly into the new smaller cog in back. Many know about the 'California Cross' for cable routing. This simply crosses derailleur cables in front of the head tube and then again inside the downtube as they route down through the cable guide shown below which on my '12 Roubaix Pro is a 2-piece cable guide. Cross of cables is minimize internal cable drag by having cable housing bends as natural as possible. Multilple or tighter radii same side routing 'may' increase internal cable drag creating lethargic up shifting in particular.
The issue of whether to run in-line cable housing adjusters has come up before and I will only add, I am a huge proponent of doing so having tuned the derailleurs on my Roubaix now for a short while. They make life a whole lot easier. I am fussy about the trim on my derailleurs and want the bike dead silent even when running slightly cross-chained which is attainable.
Since I have had the cables on and off my bike a couple of times to achieve just the right length of housing, I have learned a couple of tricks along the way:
- From the vantage point of the opening in the downtube just in front of the BB under the bike, peer down into the downtube to ensure when you cross the front and rear derailleur cables you don't wrap them one more time. Double crossing derailleur cables would hamper shift quality greatly. It is unclear whether to cross front or rear derailleur cable over the other having studied it.
I would say it doesn't matter as both cables enter the downtube at the same elevation and also end up at the same vertical height on the cable guide under the bottom bracket shown below. Put a light down the down tube when seeing whether the sheathing is crossing once only as it should when setting up the California Cross orientation.
- Which leads to the best way to install cables. Once you have the proper housing length established from under the handlebar tape to down tube, best approach is to invert the bike and rest it on its handlebar hoods and seat like a tripod. This is how we worked on bikes as kids and much easier than threading cables though the frame with the frame hanging from a frame stand. Now you can see under the BB and inside the downtube without craning your neck and much easier to fish cables through the BB cable guide.
- A further good tip is...if you don't like the length of your housings for example and need to remove them for shortening which is common after an initial build...and need to pull the cables out of the frame, restring your sheathings back over the cables and...the important point...you don't have unscrew the ICR stops on the frame. The little screws are sensitive to cross-threading and my suggestion is don't remove them unless you have to. The sheathing diameter easily penetrates the housing stops so you don't have to remove the stop ports and I suggest the fewer you need to take these off the better.
- Speaking of cross threading...a brief comment about the cable guide screw that keeps the two cable guide halves together and secure to the bottom of the BB. The thread on my new Roubaix is sadly sub par. It is not stripped, but it is ratty. This maybe just an outliar or maybe common issue on these bikes. But my bike had a thread that not only doesn't look good but offered resistance when threading the little cable guide screw which is unfortunate. There are many workarounds if the screw were to strip but it didn't. I was very sensitive to not overtorquing however because of the poor thread quality. Further, the thread engagement of the screw was insufficient...screw was spec'ed too short and existing thread wasn't used throughout its thread bore length which further stresses the amount of thread that is engaged...especially with a poor female thread. You want the BB guide screw to penetrate the BB thread depth/thickness of the shell which on my bike it didn't. This can cause water puddling on the backside of the thread inside the BB. I believe the thread is 10-32. I replaced the screw with a stainless screw one size longer for full thread engagement thru the BB shell. Because of a margin thread, I used blue loctite and believe it will be fine but word up if you run into this on your new frameset. Btw, you do not have to remove this screw and I suggest you don't unless you have to as the cables can be threaded...including sheathing without removing the bb screw and lifting one side of the cable guide. Also, there is a drainage hole adjacent to the guide so no need to remove the screw periodically for drainage if you tend to ride in the rain.
- A last note if one side of the sheathing falls inside the downtube or rear right hand chainstay which happened to me in both cases. Don't panic. The sheathing has sufficient spine to route it thru again. Simply rotate and angle the sheath and fish it back through which can be accomplished with a bit of finessing accompanied by colorful language.
Above are the salient points and a very short list. I wanted to provide some notes to those that go next that threading or recabling a new Specialized road bike with hidden routing is very easy.
A last note...and I wrote to Specialized about this...Specialized made a running change to make all ICR (internal cable routing) stops the same. They are all labeled with the no. 3.
Since brake and derailleur housings have different diameters...4mm OD for derailleur and 5mm for brake housings, general wisdom is, only derailleur housings should use ferrules into the ICR stops and not brake housings which typically don't need them anyway because of housing construction.
Hope that helps and please use this thread to provide tips you have learned along the way.
I will start by saying that anybody avoiding a hidden cable bike because they prefer the simplicity of an exposed cable frameset...shouldn't. Its super easy to set up the cables on the new bike. So want to mention this up front for anybody concerned about installing cables on the new bikes with hidden routing. Also cable drag is very low on my new build...bike upshifts solidly into the new smaller cog in back. Many know about the 'California Cross' for cable routing. This simply crosses derailleur cables in front of the head tube and then again inside the downtube as they route down through the cable guide shown below which on my '12 Roubaix Pro is a 2-piece cable guide. Cross of cables is minimize internal cable drag by having cable housing bends as natural as possible. Multilple or tighter radii same side routing 'may' increase internal cable drag creating lethargic up shifting in particular.
The issue of whether to run in-line cable housing adjusters has come up before and I will only add, I am a huge proponent of doing so having tuned the derailleurs on my Roubaix now for a short while. They make life a whole lot easier. I am fussy about the trim on my derailleurs and want the bike dead silent even when running slightly cross-chained which is attainable.
Since I have had the cables on and off my bike a couple of times to achieve just the right length of housing, I have learned a couple of tricks along the way:
- From the vantage point of the opening in the downtube just in front of the BB under the bike, peer down into the downtube to ensure when you cross the front and rear derailleur cables you don't wrap them one more time. Double crossing derailleur cables would hamper shift quality greatly. It is unclear whether to cross front or rear derailleur cable over the other having studied it.
I would say it doesn't matter as both cables enter the downtube at the same elevation and also end up at the same vertical height on the cable guide under the bottom bracket shown below. Put a light down the down tube when seeing whether the sheathing is crossing once only as it should when setting up the California Cross orientation.
- Which leads to the best way to install cables. Once you have the proper housing length established from under the handlebar tape to down tube, best approach is to invert the bike and rest it on its handlebar hoods and seat like a tripod. This is how we worked on bikes as kids and much easier than threading cables though the frame with the frame hanging from a frame stand. Now you can see under the BB and inside the downtube without craning your neck and much easier to fish cables through the BB cable guide.
- A further good tip is...if you don't like the length of your housings for example and need to remove them for shortening which is common after an initial build...and need to pull the cables out of the frame, restring your sheathings back over the cables and...the important point...you don't have unscrew the ICR stops on the frame. The little screws are sensitive to cross-threading and my suggestion is don't remove them unless you have to. The sheathing diameter easily penetrates the housing stops so you don't have to remove the stop ports and I suggest the fewer you need to take these off the better.
- Speaking of cross threading...a brief comment about the cable guide screw that keeps the two cable guide halves together and secure to the bottom of the BB. The thread on my new Roubaix is sadly sub par. It is not stripped, but it is ratty. This maybe just an outliar or maybe common issue on these bikes. But my bike had a thread that not only doesn't look good but offered resistance when threading the little cable guide screw which is unfortunate. There are many workarounds if the screw were to strip but it didn't. I was very sensitive to not overtorquing however because of the poor thread quality. Further, the thread engagement of the screw was insufficient...screw was spec'ed too short and existing thread wasn't used throughout its thread bore length which further stresses the amount of thread that is engaged...especially with a poor female thread. You want the BB guide screw to penetrate the BB thread depth/thickness of the shell which on my bike it didn't. This can cause water puddling on the backside of the thread inside the BB. I believe the thread is 10-32. I replaced the screw with a stainless screw one size longer for full thread engagement thru the BB shell. Because of a margin thread, I used blue loctite and believe it will be fine but word up if you run into this on your new frameset. Btw, you do not have to remove this screw and I suggest you don't unless you have to as the cables can be threaded...including sheathing without removing the bb screw and lifting one side of the cable guide. Also, there is a drainage hole adjacent to the guide so no need to remove the screw periodically for drainage if you tend to ride in the rain.
- A last note if one side of the sheathing falls inside the downtube or rear right hand chainstay which happened to me in both cases. Don't panic. The sheathing has sufficient spine to route it thru again. Simply rotate and angle the sheath and fish it back through which can be accomplished with a bit of finessing accompanied by colorful language.
Above are the salient points and a very short list. I wanted to provide some notes to those that go next that threading or recabling a new Specialized road bike with hidden routing is very easy.
A last note...and I wrote to Specialized about this...Specialized made a running change to make all ICR (internal cable routing) stops the same. They are all labeled with the no. 3.
Since brake and derailleur housings have different diameters...4mm OD for derailleur and 5mm for brake housings, general wisdom is, only derailleur housings should use ferrules into the ICR stops and not brake housings which typically don't need them anyway because of housing construction.
Hope that helps and please use this thread to provide tips you have learned along the way.