Replacing brake cable sheaths

Started by Steve_M90, August 13, 2016, 07:19:27 PM

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Steve_M90

To conclude the story.

Thanks for all the advice on what to do and how to do it but given that I am a novice at this, that we are talking about brake cables and that I am a nuclear engineer (we are taught to think about the consequences of failure), I decided to use a professional supplier. I chose Carrot Cycles of Lincoln. A very friendly, helpful and professional service. They helped me understand how the brake cables are connected and thus how to remove them. They made new components and performed the soldering. I decided to replace the wire and sheaths on front and rear and the result is a set of pretty responsive brakes - all the sponginess of before has disappeared.

The key thing I learned about the assembly of the cables is the presence of a brass "bolt" inside the clevice drilled to accept the wire and the nipple.

Thanks

Steve

singleminded

QuoteIf you don't fancy making your own solder bath, you can get them very cheaply via the internet. Mine works fine, even though it is Chinese, and it cost me about £15.
Thanks Paul, I didn't realise they could be got that cheaply..ordered mine last night..John

iansoady

Saw you on Midlands Today last night Paul. Looks like quite an interesting exhibition.

phutton

If you don't fancy making your own solder bath, you can get them very cheaply via the internet. Mine works fine, even though it is Chinese, and it cost me about £15.

Paul

iansoady

3.5mm sounds very thick to me. Normal brake cable would be 3mm max (probably more usually 2.5mm).

I would be replacing both inner and outer but of course if you're changing the inner size you'll need new nipples.

I use Fluxite as it's non corrosive Baker's Fluid is corrosive and needs to be carefully washed off.

Steve_M90

Thanks for all the comments.
- I have a copy of  Radco's Vintage Motorcyclist's Workshop and can see how to make a "bird's nest" in the "yokes".
- The existing wire is 3.5mm in dia. I can't find any galvanised wire this size, is 3.0mm ok?
- I understand the need to use multicore solder 60/40 tin/lead with flux (either Bakers Fluid or Fluxite Paste).
- I understand the benefit in making my own solder bath for getting a better product.

Thanks

Steve


iansoady

#8
Quote from: shorrog on August 14, 2016, 05:40:03 PM
Vic mentions the harness of the solder, and there are quite large differences between the various types. Multicore for electrical ccts is particularly soft and some of the plumbers solder is harder. Silver solder is harder still.

Graham

I can't agree. I've used multicore for decades and never had a nipple pull off. The only thing you need to look at is the composition: 60/40 tin / lead is correct. The flux core neither helps nor hinders the soldering process. 60/40 solder has a definite melting / solidifying point (is eutectic) unlike plumbers' solder which is normally 50/50 and has an intermediate range when it can be wiped, which is necessary for lead plumbing joints. And perhaps more importantly, having more lead is WEAKER rather than STRONGER. I would also avoid lead-free solder.

I use fluxite paste flux which is less corrosive than Bakers Fluid but hard to get in small quantities.

There's no need for silver solder and in fact it can be a bad thing. When I was a dopy apprentice many many years ago I allowed someone to silver solder a nipple on my Francis Barnett - he said it would be stronger than soft solder. The process overheated the cable which snapped a few days later. The nipple was however still attached......

If you look at the wikipedia page for solder you'll find more than you ever wanted to know....

https://en.wikipedia.org/wiki/Solder

Davetom

I use 'tinman's solder and bakers fluid flux, purchased online from Carrot Cycles. I made a little solder pot out of an offcut of 28mm copper pipe pinched shut in the vice. I melted a couple of inches of solder into my 'pot' ( probably about 1 square inch of solder).
I prep the cable and nipple, play a plumbing torch on it for a couple of seconds, then dip it in the bakers fluid to clean and flux it. I then heat the solder pot so it is molten, and dip the cable/nipple into it. This way, the cable/nipple is not directly (over)heated, it is heated by sitting in a molten pot of solder, and avoids weakening the cable with excessive heat.
The assembly can be dipped in and out a few times until the solder and pot start to cool. It can often lead to a small excess of solder, but that is easily cleaned off, and you can have confidence that your joint is good.
Some situations still require directly soldering the assembly, but trial and error will hopefully teach you how to do this successfully.

shorrog

Vic mentions the harness of the solder, and there are quite large differences between the various types. Multicore for electrical ccts is particularly soft and some of the plumbers solder is harder. Silver solder is harder still.

What would folks recommend?
Graham

singleminded

QuoteYou don't need that horrifically expensive tool John mentions.
Why do think I don't have one..I find that a centre punch will usually splay the cable more than enough to do the job.
Believe it or not when I worked with a lift gang and we had to re-cable a lift the cables went through the hole in the eye and the strands were then bent back,effectively doubling the cable diameter. The cable was pulled back into the eye and the recess where the doubled over cable fitted was filled with solder..John

VicYouel

Hi Steve,

In Beaming we tend not to place articles on subjects such as this that are general to most bikes and it is dealt with quite well in "Radco" as mentioned by Ian. Where do you live? I have a local mate near Bracknell who has invested in a selection of cables, a solder pot and a swaging tool from Venhill who I am sure would give you a lesson or two. He has also studied the choice of solders..... some are too soft and I have known cable strands pull through.  Most of us have learnt the hard way over the years with failed throttle and clutch cables (I still fit spares to the bike just in case) and worst of all failed brake cables.

Vic

iansoady

Making cables is relatively straightforward but MUST be done correctly, especially splaying out the cable in the countersink. It does sound as though you haven't done it before so I would practise several times especially as it's a brake cable you're working on. Radco's Vintage Motorcyclist's Workshop has a good write up. You don't need that horrifically expensive tool John mentions.

I buy cable materials as well as electrical stuff from Vehicle Wiring Products.

Some years ago I attended one of the VMCC "ride a hand change bike" days. I was cantering along on a scruffy Ariel and when I tried to use the front brake the nipple just popped off. The owner, who was a little peeved (I thought he should be grateful he wasn't aboard at the time), said he never used the front brake.....

singleminded

you have to remember that the cable is swaged after it is put through the nipple. the solder itself does not hold the nipple on,it fills the voids in the swage and stops the cable pulling through the nipple..
http://www.venhill.co.uk/Motorcycle_Tools/MISCELLANEOUS_TOOLS/VT13_CABLE_INNER_WIRE_BIRD_CAGING_TOOL.html
Take a look at the video,this tool is good but I dont have one..there is an article somewhere in the VMCC mags if i can find it..John

Steve_M90

I need to replace the sheath on the rear brake and I think I'll do the front at the same time. In the post "1935 Model 9 cable lengths" two suppliers are mentioned: T Johnson Cables GB & Venhill Engineering Limited. It suggests Johnson's would be best.

To remove the existing sheath and fit the new one I presume I need to melt the solder in one of the ends and then remake afterwards. Is there a Beaming article on the topic?

Thanks

Steve