Martin,
My only observation is that at the point where the wire is crimped you STILL have a stress point very similar to the end of a soldered joint, and invariably THAT is where the wire will flex and weaken. If you think about it, it makes perfect sense -- the connector being crimped to the wire is going to be inflexible, just like the solder joint, but with a less reliable electrical connection.
The big problem with soldering is that if you get the joint hot enough to get good wetting, you
WILL get solder wicking out 1/4 to 1/2 inch in the wire. This puts the riser out in the open where the (nicely rigid) barrel of the connector can't protect it. All that can is the heatshrink, which is still fairly flexible to some degree. Also, with a properly done crimp, there is the locked in crimp, some uncrimped but rigid barrel, then the nylon cover, then just the insulation.
Meaning the bending stress is introduced over a gradually decreasing range of support. Its much harder to achieve this with a soldered connection.
Also, with soldering, you have to use the uninsulated connectors.
With crimping, you can use the insulated connectors, which have a strain relief built into the nylon
And finally there is the matter of assembler skill.
It's quite possible to make a crappy crimped connection (vise grips as a crimping tool anyone) but given reasonable tools and a little practice, good crimps are fairly easy to achieve.
Making a good solder joint isn't rocket surgery, but it takes a lot more skill than a crimp. Add the frequently cramped and unheigenic (greasy) conditons of trying to solder on a wiring harness, and getting a good joint can become a challenge for even the best.
I've had BOTH types of connections fail at that very point, and for that reason I still would advocate a soldered joint (with flex protection at both ends) as the best solution where you don't need to regularly disconnect the circuit.
I would agree with this under some conditions if you should
never have to take the joint apart.
If you forsee
ever possibly having to, then I think you are buying yourself more trouble than it's worth. I think its harder to do a good job redoing a solder joint that was taken apart than making a new virgin one.
Incidentally, the reason why auto companies don't solder spade connections is that it would greatly increase the cost of assembly.
I also thought this when I was originally told not to solder everything.
I was assured this is not the reason.
I forget when I was told about this, but it was from a source that I trusted.
I wonder what they do on aircraft, since reliability is more of a premium, and cost is less a driver there.
If cost is no object, soldering and properly insulating/securing is still the best way to go, and I agree with your suggestion that proper flex protection in the form of either heat shrink or several layers of electrical tape will help make either connection last as long as possible.
Regards,
Well, I guess we'll have to agree to disagree.
I think that done optimally, both methods can be used to form a connection that should outlast the bike.
But I think that for most shadetree mechanics, for most connections, most of the time; they are going to get results that are closer to optimum with crimps than solder.
Don't get me wrong, I am not against soldering.
I have a very nice digital readout temperature controlled soldering station with every tip I could get for it.
I'd like to think I am quite good at soldering.
I even plan to try to hand solder some SMDs for some projects in the near future.
But there are applications and mis-applications for everything, and based on the best information I have, the wiring harness of bikes is usually a mis-application for soldered joints.
As an aside for anyone still reading our little dweebfest of best connection making :-D
Whatever you do, don't buy el-cheapo bargain brand electrical tape.
The pennies you save will be repaid with hours of frustration and
aggravation ...
Get something decent from a reputable maker.
I personally like scotch brand "super 33" (I think ... going from memory)
It sticks better, and if you do have to take it off it doesn't leave nearly the gooey slimey mess.
The connections made by the prior owner of my bike used twisted wire, covered with dollar store electrical tape ... I still curse him.
Pitch the cheap junk ... do it now.
