Wrench help -- trying to keep my sanity with cables

Triathlon Forum
1

Ok, so, I’ve completely stripped my bike. This is the first time I’ve taken a bike completely apart, so please excuse some of the naivete. I have several issues regarding cables.

First is cable housing size. From researching, there are 3 main sizes. 4, 4.5, and 5mm, yes? Just looking for confirmation.

Next, the other day I went to the LBS and asked for brake cable and housing. I got it home, looked at it and saw that the strands were running co-linear. That’s derailleur housing, no? OR, is it just no big deal using derailleur housing for brake cables? In the Zinn book, it seems that it’s important, because you want the compression strength of the housing to decrease the likelihood of a burst and thus losing brake capacity. It’s just baffling, because I was standing there talking to the mechanic for several minutes specifically re: brakes. Then he goes and gives me derailleur housing???

Next, I got Jagwire derailleur housing when I asked for derailleur housing. It’s 5mm. Then he gives me nylon ferrules. They don’t seem to fit the 5mm Jag that he gave them to me for. The OD of the ferrules is 0.225". The ferrules fit the derailleur housing that I was given that in place of brake housing. So, the ferrules that fit 5mm housing, are they all the same OD?

Regarding ferrule use, are plastic used for derailleur and metal ones for brakes? Can I get metal ones that fit 4mm housing? Taking the housing off my bike, I’ve found a mish-mash of nylon and metal on the same lines. I guess it’s just a matter of what fits in the cable stops and the bike shop not taking the time to do the best job possible since I’ve got 4mm and 5mm housing coming off the the bike.

Next, with the barrel adjusters on my brakes, when I took the brake lines out of them, there weren’t any ferrules attached. I looked inside, and it looked like the ferrule was stuck inside. But, when I pulled the first one out with pliers, I thought it broke into 2 pieces. Then when I did the second one, I realized that it looks like the pieces were designed as such. In the following photo, you see the small ring with a gap and another ferrule-like piece. What’s the purpose of these pieces? Why not use a regular ferrule? Do I need to get new barrel adjuster if I’ve thrown out what I thought was a broken ferrule?

http://i44.tinypic.com/4q3khx.jpg

Also, taking apart the brake assembly, I found the brake line running into the lever without a ferrule. Is that just bad practice? Should the shop have put one there, and should I put one there when it goes back together?

http://i43.tinypic.com/107n8ys.jpg

The housing I was given when I asked for brake housing.

http://i41.tinypic.com/2cokm01.jpg

Jagwire

http://i43.tinypic.com/20u3n6f.jpg

Rear brake housing off the bike

http://i40.tinypic.com/rr73gi.jpg

Derailleur and brake housing off the bike

http://i44.tinypic.com/mkdulj.jpg

Nylon ferrule I was given for Jagwire that doesn’t fit

http://i41.tinypic.com/zu1pmp.jpg

AAAAAAAARRRRGGGGGGHHHHHHHHH!!!

2

Thank you for confirming that I do not want to attempt my first re-cabling job five weeks before my first race. Sounds like it will take longer than that to figure it all out!

3

Usually you’ll only have 4mil and 5mil housings, with the 4mil for shifter cables and the 5mil for brake cables. Use shifter cables (as you probably know, identified by the tiny metal piece on one end) in the 4mm housings, and brake cables (identified by the larger metal pieces, either like a barrel or a mushroom) in the 5mm housings.

The nylon ferrules are usually 4mil shifter ferrules. The metal ferrules are usually for the 5mm brake housings.

I use ferrules when possible, but if they don’t fit I just put the housing directly into the (brake, derailleur, STI shifter, whatever). It can be considered bad practice, especially if you have a big angled cut in the housing. This would make the housing/cable fit weird with whatever it’s going into or coming out of. However, not really a show stopper in my book. If it shifts/stops well, that’s all that should matter. You should periodically be checking your brakes/shifting anyways so if something is a bit off you’ll know soon enough and can re-adjust.

hope that helps.

4

Usually you’ll only have 4mil and 5mil housings, with the 4mil for shifter cables and the 5mil for brake cables. Use shifter cables (as you probably know, identified by the tiny metal piece on one end) in the 4mm housings, and brake cables (identified by the larger metal pieces, either like a barrel or a mushroom) in the 5mm housings.

The nylon ferrules are usually 4mil shifter ferrules. The metal ferrules are usually for the 5mm brake housings.

I use ferrules when possible, but if they don’t fit I just put the housing directly into the (brake, derailleur, STI shifter, whatever). It can be considered bad practice, especially if you have a big angled cut in the housing. This would make the housing/cable fit weird with whatever it’s going into or coming out of. However, not really a show stopper in my book. If it shifts/stops well, that’s all that should matter. You should periodically be checking your brakes/shifting anyways so if something is a bit off you’ll know soon enough and can re-adjust.

hope that helps.

Thanks. But, can I get metal ferrules for 4mm? Wouldn’t they be more durable than nylon? I suppose that nylon should last a year (assuming we change out cables at least every year), but I guess I am just being biased.

WHY 5mm for brake and 4mm for shift? Why not have everything one size?

Any comment re: the 2 pieces I pulled out of the barrel adjuster?

5

No no. I’m just particularly anal about some things, and I feel like I have a birds nest of cable/housing that was put on when I purchased the bike that needs to be put right. It’s not hard.

6

Thanks. But, can I get metal ferrules for 4mm? Wouldn’t they be more durable than nylon? I suppose that nylon should last a year (assuming we change out cables at least every year), but I guess I am just being biased.

Probably, but don’t forget metal rusts. If you buy them by the box, they’re about 5 cents each. It can’t hurt to replace them each year with your cables.

WHY 5mm for brake and 4mm for shift? Why not have everything one size?

**No idea. **

Any comment re: the 2 pieces I pulled out of the barrel adjuster?

Get a new barrel adjuster. It will cost you $2 or so at your LBS. Don’t take apart again! :slight_smile:

7

More important than the ferrules - how is it you are cutting the housing, and do you have a proper grinder?

8

You use a grinder? I have found that it melts the outside/plastic parts of the housing.

9

I use a dremel with a cutoff wheel to cut the housing. It seems to help if you leave a piece of wire inside the housing while you cut.

I like the shimano kit that comes with the housing and cables.

I think that the brake cable is thicker becuase it is under much greater strain then shift cable.

10

I have the Park Tool cutters for when I go to cut and remount the new housing and cable. I intend on filing the housing by hand.

11

Oh, and could I just get confirmation that there isn’t some new brand of housing that looks like derailleur housing…please & thank you.

12

Heh…good luck with that. You would then need a vice to hold the cable and it is a pain in the ass. If you have a grinder, or a dremel you would be much better off.

13

just finished re-cabling, etc. shifters and brakes, on Kestrel AirFoil. Best investment you can make = “Zinn and the Art of Triathlon Bikes”…

14

rrfr,what size ferrules did you use, if any where the cable comes out of the downtube and chainstay? I’m in the middle of building my Kestrel.

Thanks!

15

Oh, and could I just get confirmation that there isn’t some new brand of housing that looks like derailleur housing…please & thank you.
AFAIK, all brake housing is spiral wound for burst strength under high braking loads. Derailler cable is linear strands for constant length (i.e. housing length won’t change while bending like brake housing does) so we don’t get ghost shifting when the bars are turned.

Some people do use derailler housing for brakes, but it’s not recommended, and I wouldn’t take the chance of my brakes failing under high load - exactly when I want them the most!

16

First is cable housing size. From researching, there are 3 main sizes. 4, 4.5, and 5mm, yes? Just looking for confirmation.
Yes. 4 & 4.5mm are derailleur housing and 5mm is brake housing.

Next, the other day I went to the LBS and asked for brake cable and housing. I got it home, looked at it and saw that the strands were running co-linear. That’s derailleur housing, no? OR, is it just no big deal using derailleur housing for brake cables? In the Zinn book, it seems that it’s important, because you want the compression strength of the housing to decrease the likelihood of a burst and thus losing brake capacity.

Yes, co-linear strands in the housing is derailleur housing. DO NOT use derailleur housing for brakes, the cable could burst under brake load and potentially cause a crash. Brake housing is wound differently and is 5mm. Use 5mm metal ferules for it.

Next, I got Jagwire derailleur housing when I asked for derailleur housing. It’s 5mm. Then he gives me nylon ferrules. They don’t seem to fit the 5mm Jag that he gave them to me for. The OD of the ferrules is 0.225". The ferrules fit the derailleur housing that I was given that in place of brake housing. So, the ferrules that fit 5mm housing, are they all the same OD?
Pretty much all ferrules have the same OD, but they all have different inside diameters corresponding to the cable size of course.

Regarding ferrule use, are plastic used for derailleur and metal ones for brakes? Can I get metal ones that fit 4mm housing? Taking the housing off my bike, I’ve found a mish-mash of nylon and metal on the same lines. I guess it’s just a matter of what fits in the cable stops and the bike shop not taking the time to do the best job possible since I’ve got 4mm and 5mm housing coming off the the bike.
Yes, some derailleur ferrules are plastic but all brake ferrules are metal. 4mm ferrules are all plastic to my knowledge, you can get metal ferrules in 4.5mm and 5mm cable sizing though. I would just go 5mm on all cables because then you only need one size of ferrules and can use the same ones for brake and derailleur cables.

Next, with the barrel adjusters on my brakes, when I took the brake lines out of them, there weren’t any ferrules attached. I looked inside, and it looked like the ferrule was stuck inside. But, when I pulled the first one out with pliers, I thought it broke into 2 pieces. Then when I did the second one, I realized that it looks like the pieces were designed as such. In the following photo, you see the small ring with a gap and another ferrule-like piece. What’s the purpose of these pieces? Why not use a regular ferrule? Do I need to get new barrel adjuster if I’ve thrown out what I thought was a broken ferrule?
I actually haven’t seen things like that before in the cable adjusters. I’ve always just used a regular ferrule on cable going into cable adjusters and have always seen it done that way.

Also, taking apart the brake assembly, I found the brake line running into the lever without a ferrule. Is that just bad practice? Should the shop have put one there, and should I put one there when it goes back together?

No, that’s the proper practice. Don’t use a ferrule on the brake line that goes into the brake lever, it will get stuck in there and foul up your braking.

17

rrfr,what size ferrules did you use, if any where the cable comes out of the downtube and chainstay? I’m in the middle of building my Kestrel.

Thanks!
assuming your talking about rear der, i used a plastic 4 on the side that comes out of chainstay (goes into piece that goes into frame) and a metal 5 (i think) on the end that goes into rear der adjustment piece. that make sense ?

18

That’s the correct way - it’s exactly what Shimano tells you to do…

19

Hi, heres some tips from our Pro Shop:

-as the other stated already, you need to use brake housing for brakes and der. housing for shifting systems. The brake housing allows the line to compress somewhat, allowing you to modulate the braking power. You don’t want any compression in the shift system otherwise it it wouldn’t shift crisply and properly. The metal interior on the brake housing is coiled, the der housing is linear.

-Use dikes to cut brake housing and then gently grind the end down square with a bench grinder or hand file. Light pressure and a water bath will help prevent melting plastic. Use cable cutters (Felcos at the shop) for the der housing as well as the cables themselves. Grind the der housings ends as well, but be careful not to catch the end in the grinder and snap the outer plastic casing. A hand file will help. With both housings, a dental pick tool can help to open and widen the hole after filing/grinding to allow the cable to pass thru with minimal friction.

-As a general rule, use a ferrule wherever it will fit, whenever you can. They fit on some, some they don’t.

-We use both plastic and metal ferrules in both 4 and 5 mm, although the brakes are always metal. Some Jagwire plastic ferrules have small o-ring seals inside to keep gunk out, but can lead to sluggish downshifts if the cable cannot pass thru it freely. I generally try to use a non-sealed alloy ferrule for both brake and der systems, and take out the seals if shift performance is affected, usually in the rear 10" or so of housing just forward of the der. Thats a common culprit. Luckily for us in San Diego wet weather isn’t a reality so the housing doesn’t really have to remain sealed with those ferrules.

-As for the 2 piece metal ferrule that came out of the barrel adjuster, I think thats just a Jagwire part that can be replaced with one solid 4mm ferrule of either plastic or alloy. I have seen them corrode themselves to the inside though, but its a cheap part that most shops should have.

Hope that helps, email me anytime with other questions.

-cory

20

? that mechanic… gave you some odd stuff.

  1. you’re right, should not use der. cables for brakes. Take it back.
  2. 5mm for der. cabling is unusual. The plastic ferrules are probably for 4mm cable so they won’t fit.
  3. I’ve always used metal ferrules for both cables, but I can’t see a problem with mixing them, except aesthetic.
  4. I think you’ve broken those barrel adjusters. Try them out, if things aren’t working right then just replace.
  5. no ferrules on brake line going into the lever.

I put a toothpick in the cable when cutting so it doesn’t crush the wiring and close the hole. Then use a plain old flat file, to square off the end of the cable.

The Jagwire stuff also is a little offbeat it seems. I replaced brake cables on my race bike and ran out, got more cables from REI. The REI cables are Novara branded, but made by Jagwire. The Jagwire-branded cable I had is thicker than the Novara cables. This extra thickness has a noticeable effect on friction. Odd. I’m inclined to just get the Shimano-packaged cable sets, like
http://www.biketiresdirect.com/...ake_cable_set/pp.htm
A little more pricey, but at least you know everything matches…