# Internal routing, what's the limit?



## 18bikes (Jan 15, 2007)

Ignoring the pros and cons of internal cable routing, what's the maximaum number of cables/hoses you've managed to get into one tube? I've got a frame coming up where it would be good to get 2 gear cables and 2 hydraulic hoses inside 1 tube, I'd want to do them in proper guide tubes (ie push cable into one hole and it pops out the other) but I"m not sure it's going to be possible. Any photos of the inside of tubes with guides in would be helpful

Thanks,
Matt

PS Most I've done before was 2 and there was certainly room for a third, but not sure about the fourth


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## Walt (Jan 23, 2004)

4 guide tubes will physically fit inside even a pretty small main triangle frame tube. Heck, a lot more than that will. Will they bang into each other on rough terrain and make noise? Maybe. Will turning the tube into swiss cheese to do all the ports be a good idea? I don't know. But there's no question that you can fit them all, at least in my mind.

That said, the most I've ever done was 2.

-Walt


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## Eric Malcolm (Dec 18, 2011)

Matt

Over in the Sticky site, Roll Call Please, Builders and Users: Page 7, there is a bike built by Chernichosky. Sorry, I'm computer challenged to be able to extract the picture and post it here. It is a pale blue, Rolhoff hub equiped bike that has 3 cables entering the top tube from the left-hand side spaced evenly apart from the HT. All 3 cables then slip into the left-hand Seat stay and exit out in the same way as they enter the top tube. I think it is Uber-Cool. 1 Hydro brake, plus 2 cables into a Std 19mm Seat-stay. The trick to this is when fitting the cables that you use sleeved down tubes that carry the wire only therefore reducing bulk and the wire cables enter and exit the frame via short butts that the outer cable slots into. Doing 4 that way is not a big deal on the Top tube as a construction, but 4 elongated drillings need support to recover lost mass of the tube.

Also, 2 hydro cables? What unusual application are you doing?

Sounds interesting.

Eric


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## shirk (Mar 24, 2004)




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## Eric Malcolm (Dec 18, 2011)

Thanks Shirk

Looks impressive Eh.

Eric


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## shirk (Mar 24, 2004)

I can't braze (yet), but I canz workz the internetz.

Looks neat. I like that he moved the seat stay to do it.

I would guess that when 18bikes says 2 hydro and 2 gear, that one of the hydro is for a stealth Reverb. Just a guess.

Are these going in the downtube? Maybe silver a sleeve/patch over the spot where the slots get put in the tube to add strength?


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## TrailMaker (Sep 16, 2007)

Yes;

Re: the Chernichosky. I liked the entry and exit of the internal routing a lot, and I like the solution past the ST, but I do not care for the stays being a-symmetrical. Just me.


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## Live Wire (Aug 27, 2007)

Most I've done was three for this bike: photo.JPG | Flickr - Photo Sharing!
Cables are internal to provide easy attachment for a frame bag.
Full length housing with stainless guide tubes in a 31.4 tube. With the curve and the fact that one had to cross from the left to the right, I don't think I could've fit another one in there. Yes, the guide tubes touch, but no, they don't make noise.


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## calstar (Mar 26, 2013)

Here's the pic of the 3 cables thru the st so you can see the flow from the tt into the st, and the asym nature of the st., although symetry would seemingly be easy to attain.

Brian


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## Meriwether (Jul 26, 2007)

I really wonder what's the limit in the number of holes you can put in a given tube before seriously reducing its integrity so that it fails sooner than later. 

Precautions like drilling the holes in the thicker portion of the butt, sure, but the holes are 1cm wide by 2-3cm long...! That's a ton of missing metal to have more than 2 in one tube atmo (sorry, it fit. Is that protected under a Copyright?). 

For my recent build I brazed on a 'patch' so that it when I drill the hole into the tube and end mill the 3cm slot in it, it will hopefully not be such a stress riser. But has anyone ever seen a tube fail at these internal cable holes?


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## Walt (Jan 23, 2004)

I was just going to mention that. It gives me the heebie-jeebies to drill holes in tubes anywhere near the head tube (especially the downtube!), but I've never seen or heard of a tube failure due to internal cable routing. That's not to say it hasn't happened, of course.

-Walt


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## 18bikes (Jan 15, 2007)

The extra hyrdo line is for a reverb stealth, it would be everything in the downtube. It's for our demo Pinion bike and I was just wondering about the possibility of cleaning up the frame a little. The bike will be a similar build to this one


18 Bikes Pinion P1.18 853 Hardtail by 18bikes, on Flickr

but the cables will be exactly the same. There is the option of running the brake along top tube/seat stay but that is more work and cable guides than needed. I do like that we've got 4 cables running in two sets on that bike so it only had 7 bottle bosses (it used bolt on guides) spread over 2 tubes. The pair under the dt at the ht are at crud catcher spacing and the lower ones on top of the dt are at bottle spacing so it kills several birds with one stone. I'd be tempted to do 2 internal/2 external but I'd only gain part of the looks but add weight. I'll have a think but I will probably just do the same as the frame above

Matt


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## DWF (Jan 12, 2004)

I'd do it all in one larger tube, full length housing. I'd probably run it from say, 2-3 o'clock on the top of the DT, then have it exit near the bottom of the DT near the BB or wherever it needs for the Pinion. Little relative stress is those areas and cap the penetrations with small reinforcements. Make sure all liners are mapped out so they're completely self draining.

Always map your internal routing on the tube and install/braze/weld the liners before installing the tube on the frame. That way if you can ensure that liners aren't touching the tube wall or other liners. Touching is bad, mkay?

FWIW, the internal routing that uses a stop for the housing and then just the cable travels through the small tube is crap. Lots of cable drag, hard to maintain. It worked OK for 8-spd stuff, but I'd never use it on current shifters/derailleurs.


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## Feldybikes (Feb 17, 2004)

Meriwether said:


> That's a ton of missing metal to have more than 2 in one tube atmo (sorry, it fit. Is that protected under a Copyright?).


Only protected when saying the meaning of the acronym doesn't actually make grammatical sense. So I think you're ok here.


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## Meriwether (Jul 26, 2007)

Feldybikes said:


> Only protected when saying the meaning of the acronym doesn't actually make grammatical sense. So I think you're ok here.


 ok grammer police. I must be missing the point tho since the purveyor of that saying uses it at the end of every/any sentence.


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## Meriwether (Jul 26, 2007)

I did this and it's probably overkill (or ineffective, you choose) but will make me sleep better when my friend's hucking stuff on the 120mm 29er with this downtube. There's one on each side (at 9 and 3).


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## Walt (Jan 23, 2004)

See, I actually think that's scary too - because you've now got a *really* stiff section of tube to deal with (ie big stress riser). I mean, better than just leaving the holes unreinforced, but I've seen just cable guides crack tubes (which is why I use the Pacenti sheet metal ones that I figure can flex a little). 

I bet it's fine though. 

Or ATMO or something?

-Walt


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## Meriwether (Jul 26, 2007)

Feel free to call it stupid, I can take it. I hope it's ok. I saw Wolfhound [/URL]do it so must be tested, mine are a bit bigger though in size. The DT is a 35mm supertherm so it's probably totally unnecessary.







If one wanted to go into the DT with all 3 cables one could make such a patch with all the cables going into that one 'guide'. 
Rody made a cool frame where three cables went into the headtube and then went their separate ways after going around the steerer somehow. Really cool idea so you don't have to drill into the front of the downtube.


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## Walt (Jan 23, 2004)

No, no I didn't mean it was stupid! I just mean *I* freak out about drilling/attaching things near the head tube, especially to the downtube. I have zero evidence that it's a problem.

-Walt


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## shirk (Mar 24, 2004)

Meriwether said:


> Rody made a cool frame.


Rody's blog is a resource of awesomeness. He fabs so many amazing items for his custom build.

A response to every questions could be WWRD (what would Rody do).

Groovy Cycleworks 330-988-0537: August 2012










Instead of a single triple, do two doubles.


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## Walt (Jan 23, 2004)

Yes, his is one of the only blogs I read because I feel like I learn something awesome every time I'm on there. 

Let's not encourage him to spend all his time blogging, though, because that man needs to be out riding more!

_Walt


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## G-reg (Jan 12, 2004)

I tried to post that Groovy Ti 650 project a few days ago but gave up because of cell phone typing. You could easily run the hydro lines through the headtube (assuming an oversized tube), and through the vent holes down the TT or DT.

The shifter cables probably won't appreciate the bending around the steerer, and would probably be happier with a smooth path in the DT. Two in near the HT and split as needed at the gearbox would be slick. I did that in Frame #3 two stainless tubes brazed in (and tacked together to prevent rattling guiding full length housing.


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## Feldybikes (Feb 17, 2004)

Whit, I was saying that your use of ATMO actually made sense. As opposed to RS, who tends to put it at the end of most sentences where it may or may not actually make sense. I was just joking that the nonsensical version was the only one protected under copyright law and since yours was comprehensible, you must not be infringing. 

And no, I have nothing useful to contribute to this thread.


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## Eric Malcolm (Dec 18, 2011)

G-Reg

The fit in the head tube is not as tight as you may think for cables to pass by the steerer. I have drawn up a head tube with a 44mm ID. The Steerer is 28.6mm. This leaves 7.7mm clearance around the steerer. Plenty of space to wriggle cables in there.
Very nice job Rody has done, I wish I had seen it earlier.

Eric


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## Meriwether (Jul 26, 2007)

Feldybikes said:


> Whit, I was saying that your use of ATMO actually made sense. As opposed to RS, who tends to put it at the end of most sentences where it may or may not actually make sense. I was just joking that the nonsensical version was the only one protected under copyright law and since yours was comprehensible, you must not be infringing.
> 
> And no, I have nothing useful to contribute to this thread.


LOL. Yes, i would agree, thanks for the clarification. 
I could try to say something witty but I can't think of anything atmo.

I wonder who has tried drilling into the head tube on a steel frame and running stainless or brass tubes through the top or downtube. You would have to braze the BB side first them thread the other end through the head tube before welding to front triangle together? Then braze the internal tubes to the HT? Since Rody's frame was Ti did he have loose housing running through the frame? Would be easier to get around the steerer smoothly big what about rattling and fishing new housing through? Couldn't figure that out from his blog.


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## jay_ntwr (Feb 15, 2008)

Meriwether said:


> I wonder who has tried drilling into the head tube on a steel frame and running stainless or brass tubes through the top or downtube.


This has been on my list to try since i received the custom head tube material from Walt a long time ago--I still haven't used any of the material yet. I'm not sure how it will work, but it works great in my head. That stuff doesn't always shake out in practice though.


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## TrailMaker (Sep 16, 2007)

jay_ntwr said:


> I'm not sure how it will work, but it works great in my head. That stuff doesn't always shake out in practice though.


Funny how that works....


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## jay_ntwr (Feb 15, 2008)

TrailMaker said:


> Funny how that works....


Yeah, tell me about it!


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## JaquesN (Sep 14, 2009)

*Merlin Newsboy*

Merlin did 3 in a titanium downtube:

The Original Merlin Newsboy aka the Ti-phoon by onespdtandem, on Flickr


The Original Merlin Newsboy aka the Ti-phoon by onespdtandem, on Flickr

(Not my photos.)


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## 18bikes (Jan 15, 2007)

Thanks for the info guys, I've pretty much decided not to do any of them internal for a couple of reasons:

1) The pinion cables exit quite high up the downtube so I wouldn't be able to get them into the butt of the tube.
2)The pinion cables would only be in the tube for about 6-7 inches so hardly seems worth it.
3)Its a lot more work on a frame that already needs a lot of work.

Going through the headtube isn't an option as I'm using our tapered headtube and a tapered fork so there probably isn't enough room for 1 cable, nevermind 4

I think a heavier duty version of this frame (44mm headtube, bigger/thicker/plain guage downtube) might work for getting them all inside but I'm not going to experiment on this one

THanks again,
Matt


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