long wires for computer

[Bikewer]

I salvaged an old Trek computer to put on my homebuilt, but of course the wires are too short for a handlebar mount. I'd have to cobble up something to put it on the stem somewhere.

Anyone try splicing same-guage wires into one of these things? Bit of solder, some shrink-wrap....

[cjs1948]

I salvaged an old Trek computer to put on my homebuilt, but of course the wires are too short for a handlebar mount. I'd have to cobble up something to put it on the stem somewhere.

Anyone try splicing same-guage wires into one of these things? Bit of solder, some shrink-wrap....
Splicing works just fine. Go to it!

Chip

[sch]

Splicing as you suggest works fine. Several of the computer companies make 'tandem length' cable sets that will work on many bents, if you can find them. On my Rotator Pursuit, I spliced in about 15". Recently the Cateye Mity 3 stopped working and I traced the failure to an open wire near the pickup. Pickup reed relay still clicked when magnet approached but remained an open circuit. I unsoldered it and used an old Avocet pickup instead.
Steve

[Bianchiriderlon]

Just be careful soldering. Many conductors these days are very light gauge "filament" type wires. These are difficult to solder. I have just bought a bent and I am contemplating having to lengthening a computer cable. My other hobby is amateur radio and I have done a lot of soldering in my time. I will use a magnifier and "third hand" soldering stand. It is a good idea to "tin" the ends of the cable prior to joining them. That will give a bit more to work with and you won't have to put the heat to it for as long. Be certain to insulate both conductors and to finish up with a length of heat-shrink tubing. Put the tubing on BEFORE soldering!

Cheers

Charles VE3HBB

[jeff-o]

I work in the electronics industry, and we ALWAYS tin the wires before soldering them.

So, uh, good advice Charles.

[Bianchiriderlon]

I work in the electronics industry, and we ALWAYS tin the wires before soldering them.

So, uh, good advice Charles.

Yeah, it's a good practice. I don't know for sure the reason for all the light gauge wire we see all over the place. it must be cheaper. I'd think that resistive losses would be higher due to the gauge. I've got tons of enameled hook-up wire. I'd probably twist together several strands in order to not overwhelm the "parent" wire I am splicing into. It would have the added advantage of being insulated from the get-go. I see you are in Waterloo. I'm just down the road in London.

Cheers

Charles

[BlazingPedals]

I've soldered plenty of Cateye leads, and they're tricky. The strands are very fine, and they are lacquered or something. You have to get the coating off the wires before you can tin them, and flux doesn't seem to be enough by itself. I like to hit the wires first with 400 grit sandpaper.

[Bianchiriderlon]

That's exactly what I am talking about. I've seen this situation in all sorts of applications. My computer has a heavier cable. That said, I've not cut it yet. I can't say, then, whether the conductors are heavier or whether it is just a case of more insulation overall.

Charles

[jeff-o]

Yeah, those tiny wires are cheaper, and lighter. They don't want weight weenies complaining about the thick cables, do they?

As for difficulty soldering, it could be a number of things. It could be that the soldering iron isn't hot enough, it could be cheap solder, it could be the wrong type of flux, or it could indeed be some sort of coating on the wires. Another way to clean the wires before soldering them is to hold the ends in a flame, this burns off any plastic or enamel that is coating the wire. Chemical solvents also get the coating off.