Cables, and the fitting of nipples

A couple of issues ago we posed the question of how to properly affix a nipple onto a Bowden-type cable, for use with either throttle, clutch, brake or other control cables, and the Old Bike Mart mail sack virtually split apart at the seams with the weigh

Steve Stirling:

Just a note about soldering nipples to cables. Have a look on www.venhill.co.uk website and look under tools birds nest tool part no 479. I think there is also a video clip showing how to use this tool. Hope this is of help to you and OBM readers.

In reply to John Southall’s letter about cable nipples; the best way is to grip the cable in a lathe chuck, and a chuck mounted in the tailstock (might have to use the collet out of a pin-vice if the lathe one will not close enough) with about ¼” between. By hand, rotate the headstock a small amount to unravel the Bowden cable and at the same time wind in the tailstock to compress the (slightly) unravelled cable - this should result in a regular ball shape.

If a lathe is not available, a pair of clamps can be made (with a slot drilled, slightly smaller than the diameter of the cable, so that it grips but does not distort). Hold one in a vice and turn the other to unravel the cable and press towards the other clamp.

How good to see a properly swaged cable end sent in by John Southall on page 20 of the May issue! Something almost identical to this was used in the manufacture of all cables at AMC. The normal ‘domestic’ method is, of course, to spread the strands as much as possible after passing the inner wire through the nipple and then fill the void between the strands with solder. This is usually satisfactory providing that everything is perfectly clean but it is frightening to occasionally find nipples soldered direct onto the cable on some used bikes that I have bought in the past. The result is always a disastrous failure. Some believe that

Uwe Karstens:

Regarding the last OBM, there was the question of how to create the mushroom.

I took two pieces of 6mm thick aluminium sheet metal, clamped them together, drilled two holes for 5mm adjusting pins, and two holes for the Bowden cables, one of 1.0mm and another of 1.5mm dia. Do it so that one half of the bore is in each piece.

Then drill into each bore a hole of 4.00mm dia, using the small bores as a centring.

I made it about 5mm deep.

Then I made the punch in my lathe.

Insert the Bowden cable between the aluminium plates, put it into the vice and insert the punch into the hole. Now use the hammer to create the “mushroom” head with a few hits of the hammer.

I think the pics are self-explanatory.

P.S.: This tip had been advertised a few years ago in the VMCC magazine. this is good enough for a lightly loaded cable like a throttle, air or magneto cable but it isn’t! Trust me - you always remember the roadside breakdowns!

Solder has very little shear strength and the strength of the connection is gained mostly by the compression of the solder trapped between the opened strands, not by the cable adhering to the nipple.

The cables at AMC were made in the ‘roof shop’ at Plumstead by Peter Hales and his assistant Eileen Ward. Unfortunately,

I don’t have a photograph of the small hand-operated press that was made in the

With reference to 'The Secret To Nipples' in Readers Letters OBM May 2020, this home-made tool is what I have used for years; easy to make and easy to use.

This is what you need to make it - Two lengths of ¾in x ⁄in or thicker of mild steel square top bar one 5in long and one 3in long and two ¼in short bolts, no nuts.

How to make it - Clamp the two together in your pillar drill vice with one end of each and the top level, drill through both parts about ½in in from the ends of the short piece to take a 1⁄in bolt but only tap the long piece, enlarge the holes in the short piece to allow the bolt to slip in, bolt the two bars together and drill carefully and slowly with plenty of fluid, three holes to hold the inner wire, through the centre of the top edge of the bar.

I used a ⁄in (1.5mm) for number 1 wire and ⁄in (2mm) for number 2, 3 and 4 wire (not the actual wire size, but smaller) or work it out for yourself. Then, in the top and bottom of the three holes drill holes /4in deep holes to same width size as nipple countersunk holes, most nipple holes are the same size, the end of the drill forms half a mushroom shape in the bottom of the ¼in deep hole.

Punches - Find some short lengths of various size mild steel 3in or 4in long round bar to make the punches, round bar to be a tight fit in the ¼in holes (will be loose when wire is in the holes), fix the short length of round bar in the lathe and find a drill of the same size and drill to the depth of the drill tip.

You only need a touch in the end of the round bar, this forms the top of the mushroom.

How to use - Loosen the bolts, cut a short length of wire to tool-room and used by them but, from memory, the lower ‘die’ consisted of a small smooth jawed vice whose jaws were machined with a vertical hole through the mating faces.

The hole was marginally smaller than the inner cable diameter and on the top face of the jaws the hole opened out into a ‘countersink’ to form the cable side of the ball end shown.

The inner cable was set a specific amount above the top face of the jaws and then clamped. The upper part (working like a small vertical press) held a concave-nosed punch that formed and closed the ball end when brought down on the cable end.

Dai Lloyd-Jones:

Removed from the vice, the inner cable was fluxed and then immersed in a bath of molten solder to fill the ball and the process repeated with the nipple in place to finish the job.

This ‘ball end’ was virtually indestructible when filled with solder but Peter’s proud boast, which he was happy to demonstrate, was that it was near impossible to make the nipple part from the cable, even without any solder being applied in the process! An overview of the AMC workshops can be found on website: www.workingatamc. london.

I wonder what happened to that tool?

John Southall (Reader’s Letters, OBM 419), was asking about how to get perfect nipples. Well firstly to cut the wire cleanly he needs a good pair of wire cutters or a cold chisel kept sharp for the purpose. Then fabricate a home made steel, brass or Dural matrix, made in two parts, drilled to about 25thou less than the diameter of the selected cable and countersunk to approx the size of intended nipple.

Next find (or make), a ‘bird’s nest’ punch, ie. a smallish punch with a deep dimple at the end. Clamp the cable hard in your home-made gizmo in a good vice with about ¼in proud.

Whack the punch on it and with any luck you should have a nicely, possibly perfectly formed nipple. Hope this helps, worked for me over 40 years. Factory, I think, had a machine to do it but same principle.

(Dear Ed, As you can probably guess I have had considerable difficulty not getting into schoolboy jokes writing this!)

Colin Humphries (James Cormish and Kevin Lay also mentioned this):

In response to a question posed by fellow reader John Southall regarding nipple ends on cables, I have the answer!

What he needs is a ‘Birdcaging tool’, which is a handy device for just such a task, and it’s available from Vehicle Wiring

Mike Caswell:

I was apprenticed at Crypton in Bridgwater in the 1960s and we had a couple of men who made all the Bowden cables. They used a ‘special punch’ to make the mushroom before dipping the end in very hot solder. They were always amenable to making the odd cable for us poor apprentices. Payment was usually ten Players No6 or Embassy Cigarettes. Happy days!

Anyway, I think that Venhill make such a tool called ‘Bird Caging Tool.’ practice with and slip it into the appropriate hole ⅛in below the top of the drilled punch hole, tighten nuts, fit tool into vice with head of bolt resting on the top of vice jaw and tighten vice, place the punch in the hole on the top of the wire and give it a couple of light knocks with a hammer, remove from vice, take out bolts and inspect.

When you are ready make up the cable but remember to slip the nipples on before crimping!

To finish, I fit the nipple end to be soldered back in a larger hole in the tool with the nipple resting on the top, clamp the tool handle in the vice to hold it, drip a couple of drops of Bakers fluid number 3 on to the nipple hole, and with a hot iron run a drop of solder into nipple hole, file off any excess. Job done!

Products in Derbyshire, who advertise in OBM – their part number for this is VT13 – and they can be contacted on 0115 9305454.

I hope that this helps. Incidentally, I have no connection to this company!

Derek Walker:

I was taught many years ago that the answer to cable nipple soldering is to bring the nipple to the solder, rather than the solder to the nipple.

Put a quantity of solder in a tin, either on a stove or heated by a gas torch.

When the solder is molten lower the prepared, fluxed cable/nipple into the molten solder until the nipple is fully covered.

Slowly withdraw, and clean up to suit. The result is a nipple that will not pull off. Providing that cable and nipple have been well cleaned, perfection is guaranteed!