# Tarmac hidden brake cable rattle?...



## roadworthy (Nov 11, 2011)

Wanted to poll the collective of new Tarmac owners with hidden cable routing. I stumbled on the following bulletin as part of the Tarmac cable installation procedure as I researched installing cables on my new Roubaix. Since the Roubaix and Tarmac have essentially the same cable routing, I am wondering if owners without the O-rings installed per the bulletin have experienced any brake cable rattle issues? Btw some know that internal brake cable rattle can affect many different frame models and not that uncommon. 
My new frame didn't come with any O-rings and perhaps the top tube geometry is sufficiently different on the Roubaix such that this issue is just specific to the Tarmac...but wondered if new Tarmac owners have experienced this issue and if so, did you install O-rings as a solution?
Thanks


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## AntelopeTG (Aug 21, 2011)

I don't know if I have the o-rings or not on my Roubaix but I do have an annoying rattle. The front hole mount on my bike looks like part "Z" though.


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## roadworthy (Nov 11, 2011)

Maybe a possible solution Antelope. Only way to isolate to see if its the brake cable rattling is to either increase cable tension over bumps by pulling on the lever which will cause rear braking of course...or removing the cable and riding the bike with just the front brake. If you figure out it is the brake cable...as mentioned...a not uncommon occurence on many bikes with hidden routing...then consider contacting Specialized and requesting the appropriate O-rings. The new Tarmac and Roubaix share very similar qualities in terms of construction including cable routing.
PS: If you pull cables from the bike, I suggest obtaining the routing sheaths from the dealer or Specialized before pulling out the cables as this will simply reinstalling the cable. Not sure how difficult it would be to fish cables thru the frame without sheaths but have to believe it wouldn't be easy.
Ride the bike with rear brake tension and see if the culprit is the brake cable rattling and let us know.

*Edit:* Just received a PM from a knowledgable member who knows these bikes and he said he has now seen the tech bulletin and even though he didn't install O-rings on his recently built Roubaix Pro and his bike is quiet over bumps...he will retrofit O-rings to his bike. He explained what the O-rings are. They are the same small diameter O-rings sold for years on exposed cable bikes...perhaps you have seen them along the top tube of mtbs. Since I am building my Roubaix right now and under no time compression with snow on the ground, I am going to implement this bulletin. Cable sheaths came with my bike pre-installed in the frame for routing. The issue one has with this bulletin is...one really needs 2 sheaths...a long one for threading the entire top tube length and an extra 8" long segment of brake cable sheath to isolate the cable within the top tube. Reason why...is the bare brake cable needs to be threaded all the way thru the top tube which requires a full length of sheathing over and above an 8" section that will stay inside the top tube with 3 small O-rings equality spaced. The bulletin is vague and as I visualize the procedure....one starts with installing the cable stop aft of the housing from the shifter...then a 8" segment of sheath with 3 O-rings pushed on...and then thread the cable with short sheath thru the top tube beginning in the front port...as the cable protrudes thru the back of the long sheath...pull the long sheath out...and then pull the bare cable thru the rear port which will pull the 8" sheath thru the front port as you insert the cable stop...then screw the cable stop to the top tube. It really is irrelevant where the 8" segment of sheathing resides within the top tube...important aspect is...the cable won't bounce and twang off the interior of the top tube...vertically isolated by the 8" length of sheathing which is there to laterally capture the O-rings equally spaced apart for best cable isolation. Before installing my rear brake cable I need to obtain some small cable O-rings and an additional short segment of brake cable sheathing.
If anybody knows where I can obtain some generic brake cable sheathing...which btw is larger diameter than derailleur cable sheathing due to cable diameter difference, please post if you would. Otherwise I have to contact Specialized for a segment of brake cable sheathing.
Hope that helps.


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## bernithebiker (Sep 26, 2011)

Yeah, this is a known fix. I did it on my SL4 S-Works cos I did get a rattle. Used some spare sheathing that I had from an old brake cable kit, then fitted the bump rings. All quiet now!


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## pdainsworth (Jun 6, 2004)

I did this... worked like a charm.

Tarmac-Amira Internal Cable Routing on Vimeo


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## roadworthy (Nov 11, 2011)

Thanks guys. Unclear as to whether the Roubaix is as susceptible to the rattle as the Tarmac.
But there is Antelope's Roubaix and maybe others. The bulletin seems to be specific to the Tarmac but...since I am cabling the bike for the first time, I don't see the point of not including a sheath and some O-rings to keep the cable from pinging off the interior of the top tube over hard bumps...so will add the O-rings and sheath.
Thanks again.


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## AntelopeTG (Aug 21, 2011)

Thanks for the video link. I watched the Roubaix cable routing video. Funny how my 2012 has the old style rear derailleur guide and one piece bottom bracket guide. This winter I guess I will try to slide the brake cable out a little and see if the o-rings were installed on the cable. I wondered how you would replace a cable since you are supposed to pull off the guide sheath after install but the video showed using a magnet. Is that how you guys do it?


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## pdainsworth (Jun 6, 2004)

AntelopeTG said:


> Thanks for the video link. I watched the Roubaix cable routing video. Funny how my 2012 has the old style rear derailleur guide and one piece bottom bracket guide. This winter I guess I will try to slide the brake cable out a little and see if the o-rings were installed on the cable. I wondered how you would replace a cable since you are supposed to pull off the guide sheath after install but the video showed using a magnet. Is that how you guys do it?


I slid a long piece of the sheath over the cable first. It needs to be long enough to extend out of the frame on both ends. Then you slide the cable out of the sheath, leaving the sheath behind. Then, when you install the new cable and donuts, you slide it back through the sheath.


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## AntelopeTG (Aug 21, 2011)

pdainsworth said:


> I slid a long piece of the sheath over the cable first. It needs to be long enough to extend out of the frame on both ends. Then you slide the cable out of the sheath, leaving the sheath behind. Then, when you install the new cable and donuts, you slide it back through the sheath.


Thanks:thumbsup:

On the O-ring rattle, could I just slide the O-rings directly on the cable? I'm not sure what sliding them on the sheath is for.


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## pdainsworth (Jun 6, 2004)

AntelopeTG said:


> Thanks:thumbsup:
> 
> On the O-ring rattle, could I just slide the O-rings directly on the cable? I'm not sure what sliding them on the sheath is for.


I think the sheath is used to prevent the o-rings from sliding down the cable over time. Eventually, I think the rattle would come back if you didn't use it. Just an educated guess, though.


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## roadworthy (Nov 11, 2011)

To add some clarity to the above as I have dug into this a bit more...I just contacted Specialized about the Roubaix. They amended the cable install PDF for the Roubaix to not only include the 'California Cross'...their name for crossing the cables inside the down tube when running the cables across the head tube from under the bar tape...but also add the same bulletin as I posted above for the Tarmac addressing brake cable rattle. So both Tarmac and Roubaix frames are affected by the rattle if you ride bad roads.

I asked Specialized to send me an extra piece of sheathing and some O-rings and they dodged my request saying most bike shops will carry extra sheath and O-rings. Some of us don't want to make the trip to the bike shop if avoidable. O-rings are available on line...Pricepoint.com has a 'bottle' of them for $13 but I only needed a few so here is a link I found:...package of 30 for 3 bucks...the good ones...octagon shaped...3 rings wide...what you want...or something similar:
Bike Tools Etc. - 1000's of bicycle tools and parts for the home mechanic!

Hopefully most of you guys that didn't build your bikes from framesets can find some sheathing for under the O-rings...maybe from the bike shop.
As pdainsworth correctly stated...slipping O-rings over the sheath...spaced say 2.5 inches apart, keep the O-rings spaced over time. This is because of a compression fit between O-ring ID and sheath OD. OK...how do you install the 8" sheath with O-rings pushed on? Pdainsworth gave good advice again. First thread the new cable thru the pre installed sheath into the front port of the top tube pushing it thru the rear port. Next, pull out the long sheath from the rear. Cut 8" off the sheath and insert O-rings over it and then push the sheath back onto the cable from the rear and push it thru the rear port in the top tube.
The sheath will likely displace laterally inside the top tube a bit but is long enough to cover the distance along the cable where the cable would vertically displace enough causing pinging against the inside of the top tube. 

Now the next question is...how do you install a new cable in the future with an 8" shorter sheath that won't make it from the front to rear port of the top tube? That is the question.  An astute member contacted me and said the sheath isn't necessary for cable routing. How so? You can use an old brake cable housing as a routing guide. Fish a long segment of old housing over the cable thru the two top tube ports from the rear...now you have your own make shift routing sheath...the brake cable diameter of 5mm will fit thru the top tube ports. Will give you guys another option. Tape a string just aft of the rear top tube port to the existing worn cable...after removing the cable stop of course. Then pull the cable thru the front port with the string in tow...until the string comes out along with the cable out the front port. Now you have a tether to tape to the new cable to pull it thru in reverse. Just make sure you use enough tape for a strong connection between string and cable so the cable won't slip off. So a couple of ways to route cables if you don't have sufficient length sheathing.

Hope that helps.
PS: if somebody finds a source for brake cable routing sheath...like the type that comes with the frameset, please post.


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## AntelopeTG (Aug 21, 2011)

Great info thanks:thumbsup:

I looked up actual O-ring sizes and it looks like 002 or 003 should work. You should be able to get them at a hardware or auto parts store. I have some sheath that came from brake cable kits from a long time ago. The idea then was to create a slick surface for the cable to ride on.


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## tetonrider (Jun 3, 2010)

roadworthy said:


> O-rings are available on line...Pricepoint.com has a 'bottle' of them for $13 but I only needed a few so here is a link I found:...package of 30 for 3 bucks...the good ones...octagon shaped...3 rings wide...what you want...or something similar:
> <<link removed as i'm not allowed to post it>>


^^ that site has a $20 minimum order, and shipping is additional. if there are several folks who want o-rings, maybe we should just put together an order for one jar and distribute 25 or so to everyone. if a few people kick in $3-5 it will work out just fine.

i have some sheathing available, but until i build up a few bikes i will not know if i have extra to spare for others. if i do, i am happy to send that out to some folks.


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## roadworthy (Nov 11, 2011)

Great offer Teton.
Ship has sailed for me but would work for others on the forum perhaps. The little O-rings could be distributed in an envelope. What I did on the 20 buck minimum is...ordered some chain lube...a few cable ends and some FSA carbon paste I use on my handlebars. That way I got my order just over $20...but shipping ain't cheap on that site either.
What I will do is post up a pic when I get the stuff to show insertion of the sheath with O-rings into the rear of the top tube. I am glad I found this before cabling my new frame. I am routing the derailleur cables now. Have one done. 
PS: Maybe hardware store O-rings would work fine Antelope...but if you look at the pic on that site I posted...believe best approach are cable donuts like that for exposed cable bikes. Best ones are Octagon shaped and 3 rings together.


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## tetonrider (Jun 3, 2010)

roadworthy said:


> Great offer Teton.
> Ship has saled for me but would work for others on the forum perhaps. The little O-rings could be distributed in an envelope. What I did on the 20 buck minimum is...ordered some chain lube...a few cable ends and some FSA carbon paste I use on my handlebars. That way I got my order just over $20...but shipping ain't cheap on that site either.
> What I will do is post up a pick when I get the stuff to show insertion of the sheath with O-rings into the rear of the top tube. I am glad I found this before cabling my new frame. I am routing the derailleur cables now. Have one done.
> PS: Maybe hardware store O-rings would work fine Antelope...but if you look at the pic on that site I posted...believe best approach are cable donuts like that for exposed cable bikes. Best ones are Octagon shaped and 3 rings together.


i don't think the type of donut will make a difference. it's just designed to prevent metal (cable) on carbon bumping....any softer/rubber surface will dampen vibration. 

if've got an old jagwire cable kit for MTB -- it has some o-rings in it. they are longer cylinders; i will cut them down and spread them along the cable.

no need to overthink it -- anything soft will do.

i think one could insert the donuts on the cable directly, if you have the means of pushing them into the frame. (i.e., no sheath)


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## roadworthy (Nov 11, 2011)

tetonrider said:


> i don't think the type of donut will make a difference. it's just designed to prevent metal (cable) on carbon bumping....any softer/rubber surface will dampen vibration.
> 
> if've got an old jagwire cable kit for MTB -- it has some o-rings in it. they are longer cylinders; i will cut them down and spread them along the cable.
> 
> ...


Likely any type of donut will do as you say...but an interference fit matters if you want them to stay 'laterally' in place along the cable. Donuts can slide down the cable over time and with vibration migrate together. This is witnessed all the time on exposed cable bikes with donuts as stand offs from the frameset. When they push together you lose their sound deadening quality as the greatest displacement of the cable is toward the center of the top tube. The purpose of the sheath is to keep the O-rings in place and spaced apart as there is greater friction between donut ID and sheath OD compared to running the donuts over a bare cable.
Of course you do what you like


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## tetonrider (Jun 3, 2010)

roadworthy said:


> Likely any type of donut will do as you say...but an interference fit matters if you want them to stay 'laterally' in place along the cable. Donuts can slide down the cable over time and with vibration migrate together. This is witnessed all the time on exposed cable bikes with donuts as stand offs from the frameset. When they push together you lose their sound deadening quality as the greatest displacement of the cable is toward the center of the top tube. The purpose of the sheath is to keep the O-rings in place and spaced apart as there is greater friction between donut ID and sheath OD compared to running the donuts over a bare cable.
> Of course you do what you like



yes--i'm very much with you. the main thing is the ID of the donut needs to be a tight fit relative to whatever it is being attached to. i suspect a little tape around the sheath might serve the same purpose - or anything softer than metal. 

the metal cable's OD can change a little bit over time due to cable stretch, so that alone is argument to use the sheath.

just saying if one doesn't have a sheath immediately available, all is not lost.


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## roadworthy (Nov 11, 2011)

tetonrider said:


> yes--i'm very much with you. the main thing is the ID of the donut needs to be a tight fit relative to whatever it is being attached to. i suspect a little tape around the sheath might serve the same purpose - or anything softer than metal.
> 
> the metal cable's OD can change a little bit over time due to cable stretch, so that alone is argument to use the sheath.
> 
> just saying if one doesn't have a sheath immediately available, all is not lost.


Agree. Speaking of Specialized bulletin's...had an interesting email exchange with Specialized Tech department. Seems as though Specialized has made a 'running change' to the screw on ICR (internal cable routing) stops...there are four on the frame...two for the top tube for rear brake...what we were discussing...and one for each derailleur on each side of the down tube. I brought it to the attention of Specialized that their PDF reflected different stops for rear brake...marked '1' and yet, all I received with my new frame were four identical ICR stops marked '3'. Well brake cable housings and brake housings are different diameter and yet Specialized decided to commonize stops...and their paperwork and video lagged the change. I didn't see a problem honestly and finished installing both derailleur cables running them across the down tube as suggested. Shifts perfectly on the stand. Just wanted to mention this if somebody wondered why the installation pdf didn't reflect the ICR stops that come with a new frameset.

PS: the Specialized rep suggested ferrules for _ALL_ ICR stops...even for brake housings into ICR stops on the top tube.
I am not convinced that brake housing ferrules will even fit within the common ICR stops...would say most of us haven't run ferrules over brake housings in years. I highly suggest running ferrules over 4mm derailleur housing however into the stops...nice fit that way and extra support for the derailleur housing ends.


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## AntelopeTG (Aug 21, 2011)

I was going to measure up from the end of the brake cable at the brake end to inside of the top tube, guess about 3 inches in from the housing stop. Pull the cable out, then put the o-rings on spaced about 4 or so inches apart from the measured end. Maybe a touch of superglue to keep them from moving. Then again I just might do the sheath method.:lol:


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## AntelopeTG (Aug 21, 2011)

When I was digging around looking for my liner, I found 6 cable donuts in an Aztec brake cable kit I had laying around. Of course this was AFTER I ordered some Hudz donuts. Anyway, I made a 10" piece of liner with 5 donuts on it. I went 10" mainly because I have a longer than usual top tube. The install went easy. I'm pleased to report after a quick ride, NO MORE RATTLE!!! A big shout out of thanks to roadworthy for bringing this topic up and having a fix.


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## Anthony3 (Aug 29, 2011)

AntelopeTG said:


> When I was digging around looking for my liner, I found 6 cable donuts in an Aztec brake cable kit I had laying around. Of course this was AFTER I ordered some Hudz donuts. Anyway, I made a 10" piece of liner with 5 donuts on it. I went 10" mainly because I have a longer than usual top tube. The install went easy. I'm pleased to report after a quick ride, NO MORE RATTLE!!! A big shout out of thanks to roadworthy for bringing this topic up and having a fix.


Well that stinks


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## roadworthy (Nov 11, 2011)

Antelope...congrats on fixing your rattle! Pretty annoying to have a nice road bike and the thing rattles over bumps. As discussed, lots of bikes across brands with hidden routing have had the dreaded rear brake cable rattle so good to know we have a viable fix.
Those donuts you used look to be fairly substantial in diameter. Unless my eye deceives, they look to be larger diameter than typical donuts placed over an exposed cable on externally routed bikes.
Well done!


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## AntelopeTG (Aug 21, 2011)

roadworthy said:


> Antelope...congrats on fixing your rattle! Pretty annoying to have a nice road bike and the thing rattles over bumps. As discussed, lots of bikes across brands with hidden routing have had the dreaded rear brake cable rattle so good to know we have a viable fix.
> Those donuts you used look to be fairly substantial in diameter. Unless my eye deceives, they look to be larger diameter than typical donuts placed over an exposed cable on externally routed bikes.
> Well done!


roadworthy,..I don't have the others I ordered yet, {Hudz}, to compare to, but these are octagon shaped ones and they measure out at 1/4inch across the flats. Does that sound big?

I'm just glad the noise is gone.!!


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## roadworthy (Nov 11, 2011)

Will be interesting to compare what you used to what each of us has on order.
I will post with the diameter of the ones I receive when they arrive.

Thanks.


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## AntelopeTG (Aug 21, 2011)

I got the Hudz donuts today. They measure 1/4" in diameter too. I think the octagon ones must be bigger do to the shape with the flats.


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## tetonrider (Jun 3, 2010)

roadworthy said:


> I brought it to the attention of Specialized that their PDF reflected different stops for rear brake...marked '1' and yet, all I received with my new frame were four identical ICR stops marked '3'.


which PDF is this?

i'll be stringing up my SL4 tomorrow. didn't closely examine what came in the bag re: cable stops and such, as i was focused on bolting on the drivetrain and getting the basics of the cockpit set.

thanks!


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## tetonrider (Jun 3, 2010)

just did the internal brake cable install on an sl4 and a venge. i used the included cable guide/sleeve for the 8" sleeve. i also had a long (~1") avid cable donut that i sliced into 4 pieces and slid it over the 8" sleeve.

seems pretty quiet, and i just reused parts i had in my tool bin (as well as the sleeve included w/ the frame sets).


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## roadworthy (Nov 11, 2011)

I elected not to install the sheathing or donuts 'yet' on my Roubaix SL3 Pro. Reason is, I wanted to ride the bike a bit and see if it rattled...and...retrofitting the sheath and donuts is super easy even after initial brake cable install. So far no rattle. Now...I haven't ridden the bike much on the rough stuff, so may very well install the sheathing if need be as I move into spring time riding.


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## eschummer (Jul 29, 2011)

I wish I had seen this thread a couple of years or so ago - I had a Specialized Sirrus with internal cable routing and the rattle from the brake cable in the top tube drove me crazy. My lbs didn't have any readily available solutions and I ended up selling the bike and got a Roubaix which so far has not had any rattles whatsoever. Then again, if I HAD seen this in time I might still not have any "real" bikes - LOL, so maybe this was a good thing after all....

Thanks all for these great contributions. I'm getting ready to redo the cabling on the Roubaix and all these suggestions will be invaluable!


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