# Best way to clean cable housings?



## CheapSkate (Feb 26, 2012)

This may sound stupid, I've never had to do this before.

I'm having a nightmare with a new build, straightforward Centaur 10. One particular problem is cable friction. I've tried all kinds of combos of cables and outers, with no real success. A typical symptom is I re-cable it, it has mediocre friction levels, I ride 10 miles, the friction builds up and up until it hardly shifts. (Yes I know it's odd, I don't understand either).

For one brief (and I mean brief) moment, with a brand new pack of Campy Ultra Low Friction housings & cable, I got perfect shifting, low friction. I rode the bike 5 miles, in a very light shower, and the shifting went to hell, awful friction.

Weird. My other Campy bikes go through rain, get washed, and go thousands and thousands of miles on their housings.

But I can't make my 5 mile housing work like new again. I've tried squirting in GT-85 teflon lube, made it worse, very notchy. I've tried re-greasing the cables. Nope. Latest attempt was squirting WD-40 in and running a brake cable in and out to clear out any crud. Better, but far from perfect.

It's doing my head in. I've spent the whole winter fiddling with this bike. For 5 brief miles I had perfect shifting. Can I get it back? Can I *^&%

_What's the best way to clean and relube a cable housing? I mean really to get it perfect._

(I don't understand why, but this bike seems incredibly sensitive to cable friction. I can use these housings on my other Campy bikes, they shift like a dream, but not this new build. It's doing my head in like nothing else)

(yes I know I could toss the housing and renew it, but if I have to do that every 5 miles it's going to get a tad pricey. I want to know what's going on with this bike first).

cheers now


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## Kristatos (Jan 10, 2008)

Is it just the front or rear derailleur or both? 

The other question I have is if that 5 mile ride uncovered some other issue and the light rain had nothing to do with the issues you experienced. For example, could the housing have not been fully seated in the ergo lever? Could something else have caused a small loss in cable tension? Since you already monkeyed with the housing I'm not sure it's possible to tell - but to answer your last question I don't rehab housing ever - I would discard it and start over. If you can't get more than 5 miles out of housing then something is wrong with the setup.


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## CheapSkate (Feb 26, 2012)

Kristatos, thanks, considered post.

Yes this bike is weird, I think it's possessed. I've spent >50 hours on it. 2 bike shops (inc one Campy expert) have looked at it. None of us can get it shift right, apart from this magic 5 miles!

It's just cable friction. The classic signs:- a heavy finger lever, and sluggish or non-existent shifts to smaller cogs, usually requiring a jiggle of the thumb button or a twang of the cable.

I have tried _everything_. Swapped bits off known good bikes. Tried 4 (count 'em) levers, 3 derailleurs, miles of cable housing. Teflon cables, Campy cables, Jagwire cables. 3 different BB cable guides. Housing on the BB guide. I even bought some Teflon tube for the BB guide.

All the components individually or collectively work well on other bikes. Basically I can swap a whole setup from my "perfect" Storck to this winter bike, and it shifts poorly.

I've even been measuring friction forces with weights on cables. Inconclusive! Similarly the Campy 1 kg lift test

The two bike shops had no idea. One relubed the cables, the Campy guy diagnosed bad cables, re-cabled it with Campy and we got the 5 miles. I haven't been back to him.

I know a fair bit about bike builds, I'm not the worlds expert but can solve most of the problems.

Brain is melting, girlfriend is about to leave me.


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## CheapSkate (Feb 26, 2012)

Actually, here's the other question....

Cable an externally routed bike with known good NOS Centaur 2010 rear derailleur, known good NOS Veloce 2010 Ultrashift lever, Deda ergo bars, cable brand X and housing brand Y. All components known & tested to work "perfectly" on another externally routed bike with same bars & near identical routing. On other bikes that exact combo shifts so well it makes grown men weep.

Friction levels mediocre, sticky thumb shifts.

Ride 10 dry(ish) miles, friction levels increase.

Try housing on another bike, works just fine.

Discard housing and cable. Rinse, repeat.

BUT when X = Y = Campag, get 5 miles of _perfect_ shifting. Then it goes downhill. Once I got perfect shifting when X = Jagwire Ripcord and Y = Campag Ultra Shift. Again only for a few miles.

Thoughts?? It's not the BB guide, see above.

Aaaaarrrrrggghhh, it's just a stainless cable in a polyethylene tube.


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## Kristatos (Jan 10, 2008)

Seems weird that you can move all the stuff to your Storck and it works fine on that frame. That would seem to indicate that the cables, housing and components are fine and that the problem lies somewhere within that winter bike/frame. I'm stumped.


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## ericjacobsen3 (Apr 27, 2007)

*suggestion*



CheapSkate said:


> Actually, here's the other question....
> 
> Cable an externally routed bike with known good NOS Centaur 2010 rear derailleur, known good NOS Veloce 2010 Ultrashift lever, Deda ergo bars, cable brand X and housing brand Y. All components known & tested to work "perfectly" on another externally routed bike with same bars & near identical routing. On other bikes that exact combo shifts so well it makes grown men weep.
> 
> ...





Here's a possibility:

Maybe a cable guide has a slot that doesn't lead to a position concentric with the seat for the housing. Cable rub & extra friction only on that frame.


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## CheapSkate (Feb 26, 2012)

Can anyone tell me whether Shimano SP-41 will work OK? I believe Roadworthy uses it.

I've always used Campag in the past, because I've only replaced cables every couple of years. But during my current testing, opening a new £28 pack of Ultra Low Friction every ride is a bit painful! SP-41 is more like £3 a metre.

I'm not worried about the last decimal place in indexing performance, or in Italian style, or offending the gods of Vicenza, I just want a pragmatic test solution.

Shimano must have a broadly similar cable friction target to Campy, right? It's just a polyethylene tube with some metal bracing?


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## CheapSkate (Feb 26, 2012)

Eric, thanks (I replied earlier but forums seem to have lost it)
I thought BB guide too, I squirted water on the road, then as soon as I got home I squirted lube, then greased. No joy. I've tried replacing it, also putting housing liner on it, also bypassing it with a bent piece of housing. No joy.

Also checked that the cable inner does not touch the frame at either of the 2 frame stops. Also tried drilling out the ferrule to a bigger hole, also tried no ferrules (on the workstand).

The downtube stop is in a slightly awkward position, it is near the gusset where the downtube meets the headtube, so the housing has to make a tiny reverse curve there to get in line for the run down to the BB guide. Thought about making a clamp on jig to bypass the cable stops, out of wood or something. I tried some experiments with duct taping the housing to the frame at that point, inconclusive IIRC. Maybe I'll try again.

It's been like this all along. I decide it's definitely the noodle; the BB guide; the bar housing; the cable; the lever. Spend an hour fiddling, waiting for the Aha! moment. Then decide its not the noodle; the etc etc. Kick the dog, have a grump. Rinse, repeat. Bah. Frame needs exorcism.

Today I think it's the housing to the bars, which is odd because in my experience the noodle suffers much worse than the bar housing what with the 180 deg bend and the crud it lives in.


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## CheapSkate (Feb 26, 2012)

OK here's where we are:

I got some new Campy cables delivered today.

I cleaned my "old" (20 miles!) piece of Campy housing with WD-40 and reamed it out with a brake cable. 

1. Put the cleaned Campy housing + Jagwire cable on the bike, all shifts were sticky
2. Put the cleaned Campy housing + new Campy cable on the bike, shifts were better, middle gears didn't stick but top & bottom of block did.
3. Put NEW out of packet Campy housing + new Campy cable on the bike, shifts were near perfect, would not stick in any gear.

So the lever is OK, the derailleur is OK, the BB guide works, for now at least. The cable routing is fine.

The problem piece of cable is the bar part, I kept the same noodle for all 3 tests, it's Campy.

I've been here before.... last time after 5 miles it started to stick up. I'm almost afraid to ride it. I'm out of Campy housing. What should I do *before* I ride it, to see what might be the cause of my sticking up?? g/f suggests turning the bars, maybe the flexing of the housing caused my problem? etc???


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## CheapSkate (Feb 26, 2012)

OK some quantitative measurements, broadly

Hang a weight on the chainstay cable, see how much weight is needed to shift from 3rd sprocket to largest. Broadly this measures the friction in the "noodle".

All with a Campag cable:-

"new out of packet" Campag Ultra Low Friction housing ~2.8 kg
My Campag housing which got contaminated and I've tried to clean, ~4.0 kg
Shimano SP-41, ~3.5 kg
Best attempt to clean contaminated Campag housing, ~3.5 kg.

So I think virgin Campag housing has ~25% lower friction than Shimano SP-41. Impressive. Why? Dunno. And if I cable this bike with out of the packet Campag, it shifts like a dream on the bench. Too scared to try it on the road yet?!

Clearly I can't clean Campag housing well enough, it seems to lose its mojo. I've asked Campag if there's a trick to cleaning it. Cyclocrossers must have this problem. Also ordered some Jagwire housing, I'll measure that too.


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## bikerjulio (Jan 19, 2010)

Cheap - can you tell us the vintage of the Centaur shifter and RD? 2012? or earlier?


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## CheapSkate (Feb 26, 2012)

All 2010. I have Ultra Shift levers with the later, clickier, detent discs, and matching 2010 Centaur carbon RD. It's got the (stronger?) semi-circular shaped spring, not the 3/4 round "Escape" (weaker?) spring. I use this identical combo on all my bikes, it shifts unbelievably well on 2 out of 3, rubbish-ly on 1 out of 3 .

I've been having a Big Think, I think I understand what's going on, post to follow. Might help other fools like me.


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## C-40 (Feb 4, 2004)

*info...*

I've used Shimano 4mm housing many times, as a replacement for Campy ultrashift housing and it seems to work fine. I always use genuine Campy cables.

If a RD cable is used, never remove it and reinstall. The bends and twists of the cable won't be in the same place when reinstalled and lots of friction is likely. I've found this out the hard way.

Centaur RDs from '07-'08 are not compatible with ultrashift levers, because the spring has insufficient strength to pull the cable back, when shifting to smaller cogs.

Some early model ultrashift levers had problems with the drum that wraps the cable and the white plastic cable guide, where the cable exits the ergo lever. Sometimes a cable head rubs on the ergo body. That has to be fixed, or the shifter will never work. There is a possibility that your shifter has problems. That said, I have some early model '09 Centaur ergos that I converted to 11 speed and they work fine. 

I still prefer routing the cable along the back of the bars, but I use short bars that have a very tight bend, close to ergo body, if the front routing is used. I like the bars, but they have a tighter bend than any others I've owned, so I avoid the front cable routing.

I also recommend leaving the rear cable loop at it's full length.


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## CheapSkate (Feb 26, 2012)

C-40 said:


> I've used Shimano 4mm housing many times, as a replacement for Campy ultrashift housing and it seems to work fine. I always use genuine Campy cables.


Thanks. I am really struggling with Shimano stuff. I have found Campy cable > Jagwire cable, Campy housing > Shimano housing. Which is odd, it's just a polyethylene tube, right? This bike seems marginal in all kinds of ways. Maybe Shimano housing just puts me over the edge.



C-40 said:


> If a RD cable is used, never remove it and reinstall. The bends and twists of the cable won't be in the same place when reinstalled and lots of friction is likely. I've found this out the hard way.


I never do. So this diagnostic is getting expensive, I am rattling through cables 



C-40 said:


> Centaur RDs from '07-'08 are not compatible with ultrashift levers, because the spring has insufficient strength to pull the cable back, when shifting to smaller cogs.


Got it, I have 2010 with the "right" shaped spring, this is useful advice though.



C-40 said:


> Some early model ultrashift levers had problems with the drum that wraps the cable and the white plastic cable guide, where the cable exits the ergo lever. .... There is a possibility that your shifter has problems.


I have the later, black, cable bush. The cables fit in fine, no evidence of scoring around the drum. I've disassembled the shifters (one had very high friction due to the finger lever return spring pressing on the spindle). Interesting.

My levers all need about 900 g force at the lever/housing interface to do clean upshifts (the force needed to pull the spindle round to its detent, particularly if you do sloppy shifts on the thumb button). That 900 g is fairly consistent across 5 levers, now I've fixed the defective one.



C-40 said:


> I still prefer routing the cable along the back of the bars, but I use short bars that have a very tight bend, close to ergo body, if the front routing is used. I like the bars, but they have a tighter bend than any others I've owned, so I avoid the front cable routing.


I've always routed on the back. I tried the front briefly, it didn't seem to make any different though it is a pretty tight bend.



C-40 said:


> I also recommend leaving the rear cable loop at it's full length.


always.

Basically, I can get really good shifting with an "all Campy" setup, but not with anything else. That's a big step forward in the last few days. I guess that indicates my bike is marginal. Which would be fine, I've always used "all Campy" in the past. No worries, I'm not so cheap that £28 every couple of years is a problem. But shifting gets worse after just a few miles, and I can't "bring it back" no matter how I try. So it's getting really expensive:- open £28 pack of Ultra Low Friction; try some stuff; ride 20 miles; get sticky.

Maybe I had a one off bad batch of Ultra Low Friction, I've never had a problem in the past, but I'm reluctant to keep installing it until I understand what's going on better.

Thanks C-40, your advice is good as always. More thinking and fiddling to do.


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## CheapSkate (Feb 26, 2012)

Campy UK says use ProGold ProLink to lube cables. (I've never tried it)

Campy UK does not recommend crossed cables, says it adds more friction (I have no opinion on that)

OK I am getting somewhere now. My bike had 3 issues (some of this may be useful for others, who knows? I'll post anyway). 2 fixed, one outstanding

1. 2 x shifters with minor defects causing high internal friction

2. very marginal "friction budget" on all my bikes, vs the Campy "1 kg pull test"

3. a weak shift off the smallest cog.... still not sorted this one

1. lever friction

I have 6 (count 'em) 2010 Veloce Ultra Shift levers. I believe the internals are unchanged to the present day, the drawings on the spare parts list look the same

Two of my six shifters, brand new out of box, had high friction internally. The finger lever return spring, which wraps round the spindle, was pressing on the spindle. In the course of ~100 miles the spring had worn a small groove. These two shifters had about 1400 g friction measured at the cable housing interface. By contrast my other shifters have about 900 g. It's an easy fix. The part which rubs is the straight part of the spring that sits in the plastic lever housing. For one lever I slipped a piece of cable housing inner over the offending spring portion; for the other I slightly bent the spring (be careful!) so that it didn't rub. Of course you have to disassemble the lever, and do a bit of trial and error with the second method.

When building this winter bike, guess which lever I chose? When I got problems, which lever did I swap to? Right, a high friction lever both times. It took ages before this dawned on me, in fact I had to measure the friction in all my levers. Just install a cable, hold the lever so the cable dangles down, then hang weights on the cable and watch for clean unwinding of the cable bush as you do bad shifts on the thumb button.

2. cable friction budget

on all 3 of my bikes, the RD can pull about 900 g at the cable housing socket via Campy Ultra Low Friction cable. That's about 600 g in the Campy "1 kg pull test". I don't know why I don't pass the 1 kg pull test. Anyway as you can see, my bikes have no friction margin left:- the lever needs about 900 g to shift cleanly, and that's just about all the RD + cabling can deliver. Even very slight increases in friction, eg using Shimano housing, seems to drop the RD pull below the lever threshold, and shifting starts to stick. so I have to be very, very careful about friction. So, it would seem ShimaNO for me.

3. bad shift off the smallest cog... not yet sorted

This is where I started, back before Xmas. I wish I'd left this one til last and sorted the friction first. 

If I put the chain on the smallest cog & click one without holding the lever over, this winter bike is unreliable. It shifts about half the time, the other half it just rattles. On the road it's a pain, I have to remember to hold the lever in a slight overshift until the shift completes. Adjusting the H spring has no effect. Winding up the cable tension ditto, I have to take up 2 or 3 full turns to get this shift good, by which time all the other upshifts have gone. Hanger alignment does nothing (alignment checked by various shops & me). Also swapped cassette, wheel & RD with known good, no dice.

By contrast my two Storcks are bulletproof. I can even stop pedalling in the smallest cog, click, and it shifts instantly as I start to pedal. Always, never fails.

It's unrelated to friction, if I plug a lever directly into the RD with a short length of housing, the winter bike is still unreliable in that shift.

All I can think of, is the Storcks have a funny RD hanger, in fact it's well outside Campy specs in terms of the horizontal offset X, Storcks seem to have X >10 mm, can't remember the exact number. Campy says 4-8 mm. The winter bike has X around 7 mm, in Campy specs. Don't know why an out of spec bike would shift better than an in spec bike  I wonder if the Storcks have springier hangers? My shifting distorts the hanger until I start to pedal, the hanger springs back and completes the shift for me

Are my expectations too high? If you stop pedalling, click, then start pedalling, does that shift off the smallest cog ALWAYS happen immediately, no rattling?


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