Connecting two cables
 

Bear with me, because I know the answer to this is technically "don't". However, I have a Sturmey Archer equipped tandem, and I just cannot find a tandem length shifter cable. It arrived with 2 single cables joined by a piece of electrical terminal block, but that's failed twice on me now, so I need a better solution.

Now, I'm trying hard to find a real cable, but in the absence of that, how could I join these in a way that wouldn't slip or seperate?

Here is a place in the US:
http://www.precisiontandems.com/catframepart.htm

Here is a place in the UK:
http://www.tandems.co.uk/products/ac...em-gear-cable/

If I was a cheap bastard, and I am, I suppose I would try to tightly twist the cable and use a nut, bolt and a couple washers to hold it together. Maybe even put a groove in the washers with a hacksaw or Dremel to act as a cable guide of sorts.

I think that might be my answer. The gear cable you linked to is a standard one for derailleurs - the Sturmey Archer ones have a different (and much smaller) end piece, sadly

Have you considered solder?

I like to cap off my cables with solder instead of crimps and it works well (given a clean cable surface)
I would still be worried about strength but its worth a shot

I have a 60", white ribbed, Philips brake cable that I have no use for. If you cut the ends off, and attach the end pieces for the 3-speed fittings, it could work - but you might run into the same separation issues.


Maybe this is what you need?

http://www.theoldbicycleshowroom.co....AYCAT&catid=27

Ooooh, could be! I'll have to measure. I've bought stuff from that guy before, and met him - he's alright.

I think the "attach the 3 speed bits" method won't fly. If I could think of a way, I could do that with a standard gear cable.

If this isn't long enough, perhaps mounting the lever on the frame could work. I think limitations in cable length might have something to do with why some Sturmey Archer gear shifters are mounted on the frame of tandems.

I'm using a cable anchor bolt, perhaps from an old Huret derailleur. I don't recall whether the hole in the bolt was originally big enough for the two SA cables or if I reamed it out. In any case it works fine. Excuse the frayed ends.
http://www.geocities.com/cyqlist/cablecon.jpg

I have also used this rather more complicated homemade gizmo with equally good results:
http://www.geocities.com/cyqlist/splicer.jpg

You could mount the shifter on the Stoker's bars.

mmaybe try cable splitters designed for seperable travel bike applications

expensive, ($20+)
see this page for options or inpiration..

http://www.sandsmachine.com/ac_cable.htm

homemade seems like a good method too

I'd second giving solder a try. It might be tough to get the cables spliced together before soldering, but it would be worth trying?

Hmmm. I do have some old Huret derailleurs that nobody on this earth wants. I'm going to measure first, to see if 60 inches is enough - it just might be. I don't think the solder thing will work, partly because of strength, and partly because I have no idea how to splice the things in the first place. I suppose I could cut the plastic insulation off the terminal block, and then just weld the whole thing together once the cables are in, as an alternative. A real actual cable will win the day though.

Cables for ski lifts are spliced by untwisting the ends and then meshing the two ends together so that they are intertwined. The spliced area ends up being quite long, maybe 50 feet or more, to spread out the forces. When they are done, you can barely see where the splice is. There are only a handful of people who can do it, so their services are pricey. I don't see why you couldn't use the same technique to splice your shift cable, untwisting maybe 4-6 inches and meshing the two sides together. You could even back it up with some solder for extra insurance. I am not so sure this would work on a brake cable, though, and as cheap as they are, why take the chance?

The only reason I'd do this is if a correct length cable is not available, and that only seems to be the case with Sturmey Archer tandem cables.

Take a modern tandem shifter or brake cable and grind/file/sand/etc the barrel end until it fits the SA shifter. Shouldn't be too hard.

-Kurt

Lapping 2 cable ends together and then wrapping with thin copper wire (striped from electrical cable) then silver solder is one method. I would make the overlap 1 inch.

another option is to find some small copper or brass tubing (made by K&S), slip the cables in from either end and crimp

both methods are simular to what we used to do to make flying lines for control line model airplanes. The crimped connections used to be good for 40+ lbs of pull and the soldered connections sometimes are above the breaking strength of the wires.

I have an idea just strange enough to be right for a 3 speed...

Construct a short S/A cable with a threaded connector on both ends like usually connects to the indicator... Then connect it to the the main length of cable with a piece of threaded stock with the same diameter and threads of an indicator. This should be possible by cutting the head off of a small bolt.

This seems like a solution that would retain the looks of the typical 3 speed, and give you enough strength...

You could construct the shorter cable to put this additional connector anywhere on the length of the cable that makes sense.

SammyBoy, the listed link is for the splitters I mention a while back. I obviously haven't taken pictures of mine, but the above listed link is the gizmo I was refering to. My Greenspeed trandem uses them because the frame has 2 S&S couplers. So $20 and you'll be good to go! :D