# To cross-cable or not to cross-cable?



## jne3 (Sep 14, 2011)

My understanding is that criss-cross cabling will reduce friction since the housing takes a more "relaxed" route. Another benefit I guess would be less cable rub on the head tube. What I'm concerned with is where the cables touch under the down tube. It's hard to imagine that there would be enough friction there to cause any problems.

So, if you have a frame that will allow for this, would you do it?


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## cxwrench (Nov 9, 2004)

sure. the cables rubbing against each other is as close to zero friction as you can get.


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## JCavilia (Sep 12, 2005)

That's the way I set up my road bike, because it gave the housings in front a gentler and more consistent curve, and I think reduced cable-housing friction, possibly improving shifting a bit, and reducing the degree to which the cable bends affect steering.

The tiny bit of friction where the cables cross seems to be insignificant. No noticeable issue in at least 10,000 miles.

If you think about the size of the contact patch where 2 cylindrical cables just over a millimeter in diameter cross, there couldn't be much friction unless there was a lot of force between them, and there's very little, because they barely touch.


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## tednugent (Apr 26, 2010)

jne3 said:


> My understanding is that criss-cross cabling will reduce friction since the housing takes a more "relaxed" route. Another benefit I guess would be less cable rub on the head tube. What I'm concerned with is where the cables touch under the down tube. It's hard to imagine that there would be enough friction there to cause any problems.
> 
> So, if you have a frame that will allow for this, would you do it?


No. In fact, on my Rockhopper, that derailleur cables were crossed on the downtube.

Since replacing the cables on the rockhopper, no longer crossed. Plus they are a smigen shorter now.


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## Wookiebiker (Sep 5, 2005)

I run my bikes with crossed cables and have had zero issues with this over years of riding.

The cable routing is much cleaner, allowing for every so slightly better shifting and you don't need those stupid "clear" stickers on the head tube.

The down-tube is a bit harder to clean after a rain ride though


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## RJP Diver (Jul 2, 2010)

jne3 said:


> So, if you have a frame that will allow for this, would you do it?


Both of my road bikes (Specialized and Cervelo) were set up this way by my LBS. No worries about the cables touching, as they barely do so. The benefit of easier routing - and the related reduction in friction - far outweigh the fact that the cables might touch.


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## exotec (Dec 28, 2010)

on my custom cyclocross the framebuilder prepared verything for criss-cross. (pic will follow after I have 10 posts done)


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## jne3 (Sep 14, 2011)

Thanks for the replies. Seems unanimous (where it applies to my situation)


```
The down-tube is a bit harder to clean after a rain ride though
```
No worries there. I'm pretty much a fair weather rider:thumbsup:


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## RJP Diver (Jul 2, 2010)

jne3 said:


> Thanks for the replies. Seems unanimous (where it applies to my situation)
> 
> 
> ```
> ...


Not really any different, I simply pass a thin rag between the cables and the down tube... just like I did on bikes where the cables are parrallel.


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## exotec (Dec 28, 2010)

exotec said:


> on my custom cyclocross the framebuilder prepared verything for criss-cross. (pic will follow after I have 10 posts done)


looks like


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## savagemann (Dec 17, 2011)

Any issues with which cable crosses which?
Some front derailleurs have a lot of cable slack when in the small ring.
Shifting into the big ring creates a lot of tension, possibly adding trim to the rear mech if the cables are crossed with the front under the rear.
Don't know if this is an issue, but i would make sure the front cable crosses over the rear.


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## onespeedbiker (May 28, 2007)

savagemann said:


> Any issues with which cable crosses which?
> Some front derailleurs have a lot of cable slack when in the small ring.
> Shifting into the big ring creates a lot of tension, possibly adding trim to the rear mech if the cables are crossed with the front under the rear.
> Don't know if this is an issue, but i would make sure the front cable crosses over the rear.


I can't imagine your scenario would any affect. Further, if the derailleurs and cables are properly adjusted, there should not be any "slack" in the rear derailleur cable. I have yet to not cross cables as it is the more elegant with less stress on the ends of the cables.


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## AndrwSwitch (May 28, 2009)

jne3 said:


> So, if you have a frame that will allow for this, would you do it?


Only one of my bikes has the stops in the right place for me to cross cables. So I do. I don't know if I'd say I notice a difference in shifting - there's quite a lot going on that can effect that - but when I run new housing, it certainly seems like I fight it less.

Never noticed any ill effects on the cables at the crossing. There'd have to be some really weird geometry for the tension to be effected, given how thin cables are and how long the run between stops is.


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## frankdatank1337 (Jul 25, 2010)

I personally like the look of crossing the cables. I've also never had a problem with it. If you are concerned about the cable rubbing on the downtube just put some frame protectors on:
Hudz Hi-Tech Cable Donutz | Buy Online | ChainReactionCycles.com


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## scirocco (Dec 7, 2010)

Agree, cross the cables if it suits the bike, cable stop position and BB guide etc. Friction between two cable inners only just touching in the same plane and 5 degrees different line is so small you would have difficulty measuring it.


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## C-40 (Feb 4, 2004)

*thoughts...*

I've done it both ways, but gave up on crossed cables quite a few years ago. You may find that the cables clatter against the downtube when riding, even if they don't touch the downtube. I've made small cable bumpers from pieces of stainless steel sheetmetal and siliconed them onto the down tube, right where the cable cross. That will eliminate the noise and prevent scratching the down tube.

There should never be any slack in a FD cable, if the tension is set properly. All that would do is create a bunch of "dead" lever travel on the shift to the big ring, but it might make sense to keep the FD cable on top.

Some frames have cable guides on the head tube, so there is no need for clear tape to protect the head tube.


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## bobski (Aug 12, 2005)

*More thoughts*

In hind sight, they should've assigned the rear shifting duties to the left lever when integrated shifting was invented. Cable routing would be inherently smoother. I think it wouldn't be all that hard to adapt to this shifting when coming from down tube shifters.


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## RJP Diver (Jul 2, 2010)

C-40 said:


> You may find that the cables clatter against the downtube when riding, even if they don't touch the downtube. I've made small cable bumpers from pieces of stainless steel sheetmetal and siliconed them onto the down tube, right where the cable cross. That will eliminate the noise and prevent scratching the down tube.


Why would crossed cables be anymore likely to contact the downtube than non-crossed cables? The run length is only marginally longer when crossed. I don't have my pythagorean theorem handy, but can't be more than 1cm longer.


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## AndrwSwitch (May 28, 2009)

Actually, I can kinda see this depending on where the stops at the head tube end are located. The change in run length, given how close together the stops are on pretty much all bicycles, would be a fraction of a millimeter. But if the stops aren't on the lowest point of the down tube, crossing the cables would mean they also cross the lowest point, rather than staying at the same distance, a little further, for the entire run from stop to stop.


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## C-40 (Feb 4, 2004)

*simple...*



RJP Diver said:


> Why would crossed cables be anymore likely to contact the downtube than non-crossed cables? The run length is only marginally longer when crossed. I don't have my pythagorean theorem handy, but can't be more than 1cm longer.


The problem has nothing to do with cable length, it's the shape of the down tube and the location of the cable stops, relative to the bottom of the tube. Downtubes that are larger in diameter near the BB shell or bladed will work fine with the cables running parallel to the tube, but not low enough to be "under" it. Try to cross a cable that's not "under" the bottom of the tube, when viewed from the side and there can be substantial interference. It simply does not work on all frames.


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## jne3 (Sep 14, 2011)

frankdatank1337 said:


> I personally like the look of crossing the cables. I've also never had a problem with it. If you are concerned about the cable rubbing on the downtube just put some frame protectors on:
> Hudz Hi-Tech Cable Donutz | Buy Online | ChainReactionCycles.com


If the cables rub on the bottom of the down tube, I think I'd just bag the whole idea. Is it common to cross cable even if the stops aren't low enough?


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## MerlinAma (Oct 11, 2005)

C-40 said:


> I've done it both ways, but gave up on crossed cables quite a few years ago.......
> There should never be any slack in a FD cable, if the tension is set properly. ........


I also gave up on crossed cables. Whatever reduction in friction I got from the cables was likely offset from the mismatch of the angle on the cables going through the cable guides under the bottom bracket area.

I've got two bikes with Dura Ace 7900, no crossed cables, and perfect shifting.

RE: front derailleur cable on 7900. If you don't leave the cable very slightly slack, it lever doesn't consistently move far enough to stay in the big ring position when shifting from small ring. At least that's my experience.

Funny this topic came up as I'm moving components to a new frame and went by a couple of shops yesterday to look at cable routing on new bikes. Saw some crossed and some not. What I noticed was more internal routing and new designs on cable stops. Many new carbon frames have the stops on the front of the headtube eliminating cable rub.


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## cxwrench (Nov 9, 2004)

MerlinAma said:


> I also gave up on crossed cables. Whatever reduction in friction I got from the cables was likely offset from the mismatch of the angle on the cables going through the cable guides under the bottom bracket area.
> 
> I've got two bikes with Dura Ace 7900, no crossed cables, and perfect shifting.
> 
> ...



this is very much the case. the front derailleur cable on 7900 has to be significantly looser than any other system out there or it won't stay in the big ring. some of the older Shimano D/A triple systems needed some slack in the cable to work correctly as well.


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## Kontact (Apr 1, 2011)

FD cable tension sets the large ring index position. The low stop sets the low ring position. If there's slack, there's slack. You don't adjust your FD tension for the low stop.


If crossing cables works, great. If not, don't do it. There is no reason to have an argument about cable crossing theory. Under BB guides are not precision instruments and are not sensitive to cable angle. If they seem to be, get a file.

Short of crossing cables, the best head tube protection is a thick tape on the headtube, not little thingys on the housing. I don't care if my disposable housing gets rubbed, but a scrape in a $4000 frame frame rub is horrible.


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## orange_julius (Jan 24, 2003)

bobski said:


> In hind sight, they should've assigned the rear shifting duties to the left lever when integrated shifting was invented. Cable routing would be inherently smoother. I think it wouldn't be all that hard to adapt to this shifting when coming from down tube shifters.


Perhaps, but most people are right-handed, and there is a lot more rear-shifting going on.

Perhaps in hindsight, they should have designed the drivetrain to sit on the left hand side of the BB. ;-)

https://prollyisnotprobably.com/2010/02/07/left-hand-drive_bruiser-PINP-thumb.jpg


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## Camilo (Jun 23, 2007)

Cross or not crossed is simply not an issue at all. Perfect shifting can be achieved either way. I prefer not crossed because then I know that my right downtube cable adjuster corresponds to my right shifter and vice versa. Just one less thing to remember for my aging mind.


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## clearanceman (Apr 15, 2013)

mine were crossed on my 2006 rockhopper but not on the 08 and not on my HT stumpjumper. The reason I am going to uncross the ones on the 2006 is the cables are bending the guides at the bottom of the downtube toward the center of the bike. The guides are starting to lean toward the center. I assume this is due to the sideways force. It took years to do this but I don't think it's good. And they were crossed from the factory.


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## clearanceman (Apr 15, 2013)

clearanceman said:


> mine were crossed on my 2006 rockhopper but not on the 08 and not on my HT stumpjumper. The reason I am going to uncross the ones on the 2006 is the cables are bending the guides at the bottom of the downtube toward the center of the bike. The guides are starting to lean toward the center. I assume this is due to the sideways force. It took years to do this but I don't think it's good. And they were crossed from the factory.


Nevermind, what I thought was bent was the guide being shaped that way and being much taller than on my other rockhopper and stumpjumper. It does mean the cable goes into the guide at an angle instead of straight on and I'll probably change it next cable change.


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## cxwrench (Nov 9, 2004)

clearanceman said:


> mine were crossed on my 2006 rockhopper but not on the 08 and not on my HT stumpjumper. The reason I am going to uncross the ones on the 2006 is the cables are bending the guides at the bottom of the downtube toward the center of the bike. The guides are starting to lean toward the center. I assume this is due to the sideways force. It took years to do this but I don't think it's good. And they were crossed from the factory.


this thread has been resting peacefully for over year. sooooooo...

View attachment 279167


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## ziscwg (Apr 19, 2010)

*Run Kitty, Run!!!! *


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