Extending a bowden cable

[dave88sw]

Hi,

I'm in the process of swapping the original zenith carb set up to a SU carb on my series.  The choke linkage is on the other side of the carb on the SU and as a result the choke cable is much too short.  I didn't think much of it at the time and bought a longer cable on ebay.  However, the original cable mounts to a sleeve on the top of the steering lock and has a switch attached under the bonnet to put the "cold start" light on the dash.  I'd rather not have to remount the cable somewhere on the dash and i would like to retain the light so is there any quick/easy way of extending the original cable. A joiner/kit readily available?  I know it's possible to make up something to do the job but it would take a fair bit of messing about and i'm very short on time to spend working on it.

 

Thanks

Dave

[Davo]

Oh poo, I'm just about to do this very job, and given that photos of the conversion kit show a choke cable I was worried this would be a problem. Just how much too short is it? 

Have you looked this? http://www.paddockspares.com/ntc3690-choke-cable-rhd-lhd-with-su-carbs.html 

[paintman]

If the added cable & its connector don't need to fit inside an outer cable you could:

Use the screw clamp type solderless cable nipples - these, if you can get them big enough for two wires to fit through: https://www.ebay.co.uk/p/2-X-6mm-Solderless-Nipples-Motorcycle-Scooter-Quad-Car-Throttle-Choke-Cable/2227300609?iid=162457987044

Cut a short length of metal tube - copper brake pipe or similar, fold the ends of the cable back on themselves, hook one over the other, slide the metal tube over & crimp.

I make wire pike traces using crimps from tackle shops, but I doubt they would stock ones with a large enough bore - if you're near one that sells sea fishing tackle then they may well have as they are also used for heavy wire or nylon for sharking.

Would an electrical cable crimp connector work? Flare the cable end slightly, apply & small blob of solder, push into connector & crimp. Repeat for other cable. The flare would prevent pulling out. Much the same way as I used to do the lever ends of motorcycle brake levers with the solder nipples

Edited December 23, 2017 by paintman

[Davo]

All good ideas, thank you. I was thinking, (depending on how much too short the cable was), of horribly bodging up artfully crafting a cable mounting clamp for the outer cable that held it in place, (presumably some distance from where you would really like it to be!), and then making an extended linkage going down to the choke lever. It's no doubt one of those things that will need some experimentation and has to be "just right" to work properly. 

[Tanuki]

What about:

Putting the tubular end-nipple things on the outside sheaths of both cables.

Then get 2 copper-pipe 'end feed' blanking caps and a short length of copper tube.

Drill holes in the ends of the blanking caps; thread one over each end of the bowden-cables to be joined - then put the copper tube on one, and join the inners of the bowden-cables together using the 'barrel' and screws salvaged from an electrical 'choc-block' connector.

Then slide the blanking-caps down on to the tube (which will hide/protect the choc-block barrel and prevent water/mud/gunge getting in).

[dave88sw]

Thanks for the suggestions so far.

Davo, I'm using an HIF44, the whole linkage is on the left hand side of the carb (viewed from drivers seat) so the choke cable is probably about 12" too short when you consider it needs to do a long sweeping bend round the front. If you use a carb with the linkage the other side the throttle gets more difficult but the choke is easier 😂.

Paintman, unfortunately I think the outer will need extending too. Useful information though, I had considered crimping the inners together and mounting the outers of 2 separate cables so one pulls the other.

Tanuki, it took me a while to picture all that but that does sound like it would work quite well. I'll see what I can do with it.

Thanks 

Dave

[paintman]

In which case any of these may suit as you can then make up whatever length you need:

http://www.ebay.co.uk/bhp/bowden-cable

Or local bicycle shop.

Edited December 24, 2017 by paintman

[Scotts90]

I've TIGd a Bowden cable extension onto a heater control before...was more of an experiment but it worked out ok. It wasn't much (only a couple of inches) so the outer sheath didn't need to be there. The join did pull back into the sheath so required gentle dressing off.

[Davo]

On 12/24/2017 at 6:15 PM, dave88sw said:

Thanks for the suggestions so far.

Davo, I'm using an HIF44, the whole linkage is on the left hand side of the carb (viewed from drivers seat) so the choke cable is probably about 12" too short when you consider it needs to do a long sweeping bend round the front. If you use a carb with the linkage the other side the throttle gets more difficult but the choke is easier 😂.

Paintman, unfortunately I think the outer will need extending too. Useful information though, I had considered crimping the inners together and mounting the outers of 2 separate cables so one pulls the other.

Tanuki, it took me a while to picture all that but that does sound like it would work quite well. I'll see what I can do with it.

Thanks 

Dave

I forgot to ask: what vehicle is yours? Mine is a Range Rover, and I'm using HIF6s, so no different to yours as far as the cold start is concerned. The choke cable is pretty much in the right area anyway and for me looks like either being just about okay, or too short by a bare amount. I suppose I'll find out this week! 

[dave88sw]

Ah, mine is a series 3 2.25 so only a single SU.  You might be lucky with yours, the cable is probably somewhere near being right. 

I'm going to try and get the new manifold and carb mounted up shortly after new year and i think i'll have a go using a second cable pulled by the original to get it all working, it would be nice not to have to remove anything original.

 

Thanks

Dave

[Davo]

Ha ha, I read Zenith as in CD175, not 36IV and then started making assumptions. The lack of plurals should have given it away!  Sorry for the confusion!

So yours would be a SIII with the choke knob over at the RH side. Yes, a separate assembly as you say would work pretty well, though I think all the ideas here are good.