When do you replace cable/housings?

[swc7916]

Just wondering...Do you replace cables and housings on a regular schedule (i.e.: as part of a yearly "overhaul") or only when you start having problems with them? Do you replace them together or go through more than one cable for each change of housings? (I would never replace the housing without replacing the cable, but it's much easier to leave the housing on and just thread a new cable through it.) Which gives you trouble first, the cable or the housing? What kind of problems have you experienced; cable breakage, stretch, lining wearing out? Do you have a favorite cable set? Thanks.

[jgg3]

Housing can last many years. Typically, you replace it when it gets damaged, but I supposed a regular schedule of every 5 years might be ok. I have had bikes with the same housing for 20 years. It all depends on how much abuse it is taking, what type it is, etc. The teflon lined stuff is very good. But as soon as anything gets kinked or bent, it should be replaced.

[TandemGeek]

This is one of those "it depends" question / answers: see below.

Rear derailleur cable about one a year, the front and brake cables as needed. Cable housing only gets replaced once it's clear that the lining is breaking down or has become contaminated as evidenced by what comes out on a cable when trouble-shooting balky shifting or brake return action and at that point I usually replace all the cables and housing as a general refresh.

Much of "when needed" depends on the conditions we've been riding in and how much a given bike or tandem gets used (we have had at least two road tandems in the stable since '02). So, in some years one tandem may see 3,000 miles of use, whereas the other only gets ridden a 1,000. However, if the 1,000 was in the winter, it may start having cable issues before the higher mileage bike. Of course, we also live in a place where the roads are constantly undulating with the occasional hill or mountain thrown in so we do a lot of shifting and braking. If someone lives in the flat lands where there is a low demand on shifting, braking, and rear tires will last for a couple thousand miles (climbing hills really wears down rear tire tread), then cable life should be significantly longer.

Rear derailleur cable breakage at the shifters (STI & Ergo) is the most common and also the most troublesome, which is why they tend to get replaced on a scheduled basis. The front derailleur will begin to fray in the same place, but since it's utilization is a fraction of the rear derailleur, it takes a while before they begin to break.

For anyone using integrated shifters with linear-pull / V-brakes that have the Travel Agent cable pull modifiers, you need to be attentive to those relative to cable fraying as well. We don't use them so I don't have a feel for how long the replacement intervals might be, being mindful of the earlier comments about personal riding habits / terrain / mileage / conditions.

As for which brand... I usually go ahead a snap up Campy cable sets when I see them on sale or priced attractively on Ebay. The housing in a standard set is all you need for a tandem. For cables, I can the single bike cables on our travel tandem but it takes two sets, which works just fine since our non-travel tandem needs tandem length cables. For those I buy the generic stainless steel ones from Performance, Jenson USA, etc... when I see them on sale for about $2/ea.

[sch]

Stainless cables are a must, avoiding the occult rusting problems of steel cables with
exposed cable between cable stops which get water into the cable housing. You
do not want a brake cable to snap on a downhill. Der cable snap you can survive, brake
cable snap would be a disaster. Apart from that consideration, brake cables tend to
last a very long time, where as derailler cables with their smaller OD and tight wrap around
the drum in the shifter start fraying inside the shifter after a few years. Best to replace
every 6-10 kmiles, or at least detach from the der clamp and slide them out 3-4 inches to
check the most vulnerable part inside the shifter (brifter/DT/barend or twist grip).

[swc7916]

So.. The jist of it is: The housings last a long time so there's not need to replace them unless they're obviously damaged, watch the cables for damage and replace when they show signs, and replace the derailleur cables (especially the rear) on a regular basis as a preventative measure.

On replacing cables: Do you "prestretch" your cables before installation? If so, what is the procedure?

[TandemGeek]

Do you "prestretch" your cables before installation? If so, what is the procedure?

After installation of the rear derailleur cable only and it's nothing dramatic: before dialing in the rear derailleur trim -- and with the bike sitting static in the work stand -- I simply over-shift the derailleur with moderate hand force; about 50% more effort than it would take to shift. The derailleur can't move much since the chain is pushing up against the cassette (remember, the bike's static; nothing's rotating). All it seems to do is to eliminate the break-in period where you would otherwise find yourself making small adjustments via the barrel adjusters at the downtube.

[brewer45]

I never replace cables/housings. That's a job for my LBS.

Cheers!

[zonatandem]

If it's working OK, if it's not broken . . . leave it alone!
Typical failure with barcon shifters is the rear der. (right) cable will fray where it leaves the barcon. A dab of lube/oil/vaseline once a year on that spot will facilitate shifting and minimize friction issues.
Having said that, with 18,000+ miles on our Zona tandem have not had any cable failure.
In over 200,000 miles of tandeming have broken only one brake cable. Seems rear der. cable is the most prone to failure . . . used most often and it is the longest.
Good quality cable and housing will last and last and last . . .
When we install new cable we usually run the cable through a block of canning wax.
Pedal n TWOgether!
Rudy and Kay/zonatandem

[JanMM]

I've only changed out all the cables and housings once on our 2000 KHS Tandemania Comp. We only ride it April - October and never in foul weather or off road. Not a lot of miles, either. If it didn't seem to be working well, tho, I wouldn't hesitate to change it out.

[dfcas]

I'll be the lone voice of dissent here- I replace the rear derailleur cable at least once a year.I also replace the rear housing loop at this time. I find all other cables/housings to be much less critical and only replace them as needed.

The old rear cable becomes the new front cable. The most weathered part of a rear derailleur/brake cable gets cut off,and is fine for front use.

Note that I use Campy Ergo levers and front derailleur shifting is much more verastile and less finicky than Shimano STI front shifting, which I abhor and refuse to use.

dan

[merlinextraligh]

Standard advice 30 years ago was replace cables once a year. I actually broke a derailleur cable or two back then.

I never replace cables now, and don't recall the last one breaking.

The original cables and housings on our 1993 Burley Duet are fine.

If its not visibly worn, and the bike is braking and shifting smoothly, I'd leave them alone, other than an occasional drop of lubricant.

[jgg3]

I just got some nice gear indicators, and am planning to replace my derailleur cables, even though they don't really need it. Does someone have a good source for tandem-length cables? I could probably just shorten the old rear one to repurpose for the front derailleur, but still would like to know who carries tandem cables (on line).

[lopsided]

thethirdhand.com and biketoolsetc.com are good sources for tandem length cables.

[regomatic]

Cleaning the bike after last W/E's rides I noticed a frayed strand on the rear derailleur cable where it turned aft under the front BB. It had about 3000 miles on it and gets shifted plenty.

I'm still learning a lot of this stuff, so I took it to my independent mechanic/ maintenance mentor who works out of her home based shop. She showed me how to replace the cable and added a plastic sleeve that goes around the cable to reduce friction at the turn. She also commented that the cable connectors used on travel bikes were a good idea on any tandem as they allow for the use of two readily available cables of single bike length, instead of trying to track down tandem length cables on a tour or on short notice for next week's ride. She had a cable to fit within reach of her workstand when I walked in. If I needed a tandem length she would have had to order it.

[TandemGeek]

Does someone have a good source for tandem-length cables?

Almost all of the Etailers have them in stock; you just need to search on 'tandem' to find the tandem-specific stuff like extra-long cables. The trick is finding them on sale. Anyway, to actually find them quickly just GOOGLE on the name of an Etailer and 'tandem cable'. For Example, Jenson USA tandem cable (http://www.jensonusa.com/store/product/CA409A24-Jagwire+Tandem+Derailleur+Cable.aspx?sc=FRGL) will bring up a page with Jenson's Jagwire-brand tandem length cables... and the prices don't look bad either. Nashbar tandem cable (http://www.nashbar.com/profile.cfm?category=600074&subcategory=60001027&brand=&sku=2439&storetype=&estoreid=&pagename=Shop%20by%20Subcat%3A%20Brake%20Cable) results yield a more expensive product that doesn't seem all that much better.

However, I agree with Regomatic's observation / shared sentiment from his wrench: the use of something like a daVinci 'Easy Split' cable splitter eliminates the need for tandem length cables and that's a good thing for three reasons:

1. You can almost always find one or two standard length cables.
2. It's usually the front 1/2 of the derailleur cables that wear-out; the back 1/2 will last a really long time.
3. It could be my imagination, but it seems like cable runs using splitters have less elasticity than the uninterrupted tandem-length cables: in other words, they don't seem to stretch as readily and/or don't need as much adjustment.

[regomatic]

Whoo-Hoo!!

I posted something mechanical and TG agreed without debate or derision.

Have I finally arrived?

Is there group hug on the horizon?

Not getting my hopes too high, just checking.

[jgg3]

I posted something mechanical and TG agreed without debate or derision.
In defense of TG, I don't recall him ever being derisive.

[oldacura]

I used to replace cables / housings every so often as a "tune-up". Now however, I agree w/Rudy - if it ain't broke, don't fix it. For cables especially, if they're not kinked or frayed, they are really no different than when installed. If they are dirty & causing friction within the housings, they can be cleaned easily with steel wool or the like. As far as the housings go, depending on their location on the bike, they can get contaminated internally and very difficult to clean. So, critical ones - like the rear der loop may need to be replaced if shifting gets sketchy.

[regomatic]

In defense of TG, I don't recall him ever being derisive.


My apologies, my post wasn't intended to be derisive either, I like to use alliteration when I write, probably should have found a better word.

[Artmo]

Whoo-Hoo!!

I posted something mechanical and TG agreed without debate or derision.

Have I finally arrived?

Is there group hug on the horizon?

Not getting my hopes too high, just checking.


I'll give you a hug next time I see you, Reg!!

Just done 51 mi today on "your" tandem on the Silver Comet Trail in Atlanta. The T2000 still flies!