Cable routing

Discuss light weight issues concerning road bikes & parts.
kgibbo1868
Posts: 157
Joined: Thu Jun 21, 2012 6:36 pm

by kgibbo1868

I decided to re cable my bike for the first time. It’s not perfect but I thinks it is much better than the way it was done previously. I would love to see some other examples of “good cable routing”. Feel free to critique my job as I am always looking for possible improvements.

Before
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After
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ImageImage

So far I am really happy with the shifting using Jagwire. The cables are running in a sealed liner and have a very low friction. I ran the sealed tubing in one continues piece from the shifter to just before both derailleurs, so they should stay clean (especially at the BB).

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by Weenie


NiFTY
Posts: 1222
Joined: Sat May 26, 2012 11:26 pm

by NiFTY

Looks good.
Evo 4.9kg SL3 6.64kg Slice RS 8.89kg viewtopic.php?f=10&t=110579" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

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wheelbuilder
Posts: 533
Joined: Wed Feb 08, 2017 2:10 am

by wheelbuilder

Nice work!

alcatraz
Posts: 1301
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

The cables are a bit on the short side. Front brake centering can be tricky. Also the derailleur might be held back by the cable in small/small and cause a larger gap to the cassette than necessary. (lose some small cog shifting quality)

The good thing is you can add a link if you need. Right?

/a

dmulligan
Posts: 313
Joined: Wed Jul 23, 2014 6:16 pm

by dmulligan

I have exactly the same frame and I'm about to replace my brake housings. Could the rear housing across the seat tube be just a little shorter than the OP ran it?

Also was the comment about the front brake housing being a little short specific to that brake caliper (campy?)? The OP ran it about as short as I was thinking of doing but I've got 6800 brake calipers. I've never found them to be difficult to center but I've also never had the cable housing that short.

Thanks!
D

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kgibbo1868
Posts: 157
Joined: Thu Jun 21, 2012 6:36 pm

by kgibbo1868

alcatraz wrote:
Wed Mar 07, 2018 8:37 am
The cables are a bit on the short side. Front brake centering can be tricky. Also the derailleur might be held back by the cable in small/small and cause a larger gap to the cassette than necessary. (lose some small cog shifting quality)

The good thing is you can add a link if you need. Right?

/a
Front brake has been fine so far. You are right about it being good that I can add or remove a link if required. There have been no issues with the rear derailleur either regarding shifting. In fact I can say this is the best (more crisp and precise) my rear derailleur has ever shifted, but I attribute that to a very slick housing.
Pain is my friend!

kgibbo1868
Posts: 157
Joined: Thu Jun 21, 2012 6:36 pm

by kgibbo1868

dmulligan wrote:
Wed Mar 07, 2018 4:05 pm
I have exactly the same frame and I'm about to replace my brake housings. Could the rear housing across the seat tube be just a little shorter than the OP ran it?

Also was the comment about the front brake housing being a little short specific to that brake caliper (campy?)? The OP ran it about as short as I was thinking of doing but I've got 6800 brake calipers. I've never found them to be difficult to center but I've also never had the cable housing that short.

Thanks!
D

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The rear brake housing could definatly be run 1 or 2 links less than what I did if you prefer the looks of that. I was trying for a smooth arc that lined up nicely when attaching to the brake caliper (sram red). The ability to add / remove links is very nice when you are setting up the cables. :thumbup:
Pain is my friend!

kgibbo1868
Posts: 157
Joined: Thu Jun 21, 2012 6:36 pm

by kgibbo1868

I used Calnago’s trek as a model for what I was trying to achieve.
Image
Image
Image


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alcatraz
Posts: 1301
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

The first gen red derailleur has a relatively steep angle on the cable input so it generally needs more cable than other bikes going into it.

/a

RussellS
Posts: 792
Joined: Wed Feb 03, 2010 1:31 am

by RussellS

kgibbo1868 wrote:
Wed Mar 07, 2018 11:25 pm
I used Calnago’s trek as a model for what I was trying to achieve.
Image
I do not like switching the derailleur cables from side to side, as was done in this picture. The rear shifter cable is on the drive side, so it should only run on the drive side. In the picture it goes to the non drive side and then crosses the front derailleur cable to get back to the drive side under the bottom bracket. No thanks.

Regarding your pictures at the beginning. The rear derailleur hanger and seattube rear brake cables look good. As for the cables in front of the bars, I'd have to see them in person to decide if they are good or not. Can't really tell from the picture. You need to move the bars side to side and watch how the cables move. About the only comment is the front brake cable seemed too short.

kgibbo1868
Posts: 157
Joined: Thu Jun 21, 2012 6:36 pm

by kgibbo1868

RussellS wrote:
Thu Mar 08, 2018 12:47 am
kgibbo1868 wrote:
Wed Mar 07, 2018 11:25 pm
I used Calnago’s trek as a model for what I was trying to achieve.
Image
I do not like switching the derailleur cables from side to side, as was done in this picture. The rear shifter cable is on the drive side, so it should only run on the drive side. In the picture it goes to the non drive side and then crosses the front derailleur cable to get back to the drive side under the bottom bracket. No thanks.

Regarding your pictures at the beginning. The rear derailleur hanger and seattube rear brake cables look good. As for the cables in front of the bars, I'd have to see them in person to decide if they are good or not. Can't really tell from the picture. You need to move the bars side to side and watch how the cables move. About the only comment is the front brake cable seemed too short.
Thanks Russell, I agree the front brake cable could use an extra link or two when I look at it now, but functionally it works well as the fork obviously moves with the bars so the cable spacing does not change, unlike the derailleur / rear brake cables.

I don't mind a single cross in the downtube as it doesnt seem to hinder the performance. Also, with the Jagwires I have run the inner liner through the downtube across the BB and ended it just before the derailleur so I wont have cable rubbing against cable in the downtube.
Pain is my friend!

MikeD
Posts: 143
Joined: Thu Dec 11, 2014 9:55 pm

by MikeD

If your cable housings are rubbing against each other or against your frame, use those Jagwire rubber protector things.

Bondurant
Posts: 91
Joined: Tue Mar 01, 2011 12:28 pm

by Bondurant

RussellS wrote:
Thu Mar 08, 2018 12:47 am
The rear shifter cable is on the drive side, so it should only run on the drive side.
That doesn't make any logical sense. The cable run on the Trek is routed as it is to reduce sharp bends and therefore friction. Friction will reduce shifting performance far more than running a cable on the 'wrong' side.

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Calnago
Posts: 6634
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

Little bit of history...
Back in the day of skinny steel tubes... it was quite common, especially on really small bikes, to route cables this way, and the exposed derailleur cables crossed each other underneath the downtube. It made a much smoother arc in the housing from the handlebars to the downtube, which of course, results in less friction and better shifitng. And that was with 8 and 9 speed stuff. The only reason I didn't like it back then was an aesthetic one, I just really didn't like the look of cables crossing like that underneath the downtube... I much preferred the look of the exposed cables running along a straight line down their respective sides... "Mind the lanes, cables!". It just looked nicer to me, yet I understood the functional reasoning behind the crossing under the downtube method. I also liked to "frame" the headtube badge, be it a Colnago logo or whatever, between the elipse of the cables crossing in front of the headtube. Again, it was purely an aesthetic thing.

Then tubes started getting fatter, and derailleur housing bosses on the downtube were not low enough to allow cable crossings underneath the downtube, so that type of routing became impossible for awhile. Until the tubes got even fatter and internal cable routing became popular. All of a sudden, with the unsightly cable cross underneath the downtube now able to be hidden within the downtube itself, I really had no reason not to do it, and lot of reasons to do it...
1) It results in only one rather large radius bend from the shifter to the downtube... it's almost as if the housing is in a straight line. Bottom line is this reduces friction, a lot, compared to the tight radius S bends that have to occur otherwise. You can do a simple experiment to see the difference: take a new umounted shifter housing and insert a derailleur cable through it. Bend it into an S shape and pull the derailleur cable through. Now let it go and just make one large arc in it and do the same test. I don't think you even need to go through the exercise to realize which one is going to have less friction. Now, imagine squishing that S shape between the bars and the downtube of a small frame... ok... enough said.
2) If you buy the first point above, and you realize how adding more gears (11spds) have meant that each shift requires a smaller amount of cable pull than years gone by, and you also realize that the less friction the better, then from a functional perspective I can't see how anyone could argue against this routing.
3) From an aesthetic point of view, the crossing of cables occurs inside the downtube, so no more unsightly crossing underneatht the downtube. There is no added friction, unless you can convince me that a 1.2mm steel derailleur cable passing over another for 2-3mm, is being held up somehow. The only thing you have to be careful about is that the cables don't actually get twisted around each other inside the downtube, because that would indeed cause some shifting issues.
4) There is no point where the cables are rubbing on the headtube or other parts of the frame. Saying you can put a sleeve around the housing that rubs on the headtube has never sat well with me, because now instead of the actual cable housing rubbing the abrasive dirt into your headtube, you now have the sleeve doing that job. It does protect you cable housing however . And I really hate those clear stick on patches where cables rub on the frame.

Ultimately, you can use whichever method you like... I'm currently using this method on virutally all my builds, except where it's impossible (My C50 for example, won't allow it).

Oh, and for the rear derailleur housing... that deserves just a brief mention. The key to the correct length for that will depend on your frame ports and bosses, as many rear derailleur cables just exit out fo the end of the chainstay now, versus being attached to a bosse several centimeters up and underneath the chainstay. Also, the SRAM derailleurs typically require a much larger loop so that the cable enters without too tight a radius. The new Shimnao derialleurs actually come with a much more flexible piece of derailleur housing just for this purpsoe, because the length to their derailleur entry point is so much shorter than it has been in the past.

Then, finally, from an aesthetic point of view... I strive to have all the cable housings intersect within a 5mm circle or so right below the center of the stem out front. If I see a cable job like that, I know the builder probably took the same meticulous care in putting together the rest of the bike. Sloppy cables, sloppy build.
Last edited by Calnago on Thu Mar 08, 2018 7:46 pm, edited 1 time in total.
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kgibbo1868
Posts: 157
Joined: Thu Jun 21, 2012 6:36 pm

by kgibbo1868

Two more links in the front brake and I am happy now, no more tinkering..... for now.....

Image


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Pain is my friend!

by Weenie


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