2_i 

Sure, good advice. Here, there were other considerations, though. The two ends, where the connectors could be moved, were already overcrowded, so midway became a choice. Another, is that I ended up combining components not originally meant to work together and I wanted to retain as much of original wire as possible not wanting to venture yet into opening them. With this the connectors ended up being wherever the wire ran out.

Bike electrics is quite a niche area. Economically, it does not make much sense to optimize connectors specifically for such a market. In practice we have to repurpose connectors optimized for something else. That leads to maybe more struggle than elsewhere. To ensure strain relief on a bike, I now start putting a piece of a shift cable into the heatshrink sleeve.

u235

Same with crimping AND having the right tool for the exact thing you are crimping together. Not having the right equipment and skill is ripe for eventual failure there too. In either situation, I wouldn't solder or pre tin a crimp. I have soldered or crimped as required critical equipment professionally. In the regular world where most people are using run of the mill multipurpose crimp kits and an all in one squeeze crimper, gas tight is not an option.

steelbikeguy

I just noticed the reference to blocked wire. It's probably overkill for bikes, but I have used it on construction equipment... some of the connectors end up under water for prolonged periods, despite the gear not being expressly designed for that. I've seen damage where water did wick up the strands of a length of water, cause corrosion of the circuit board, leading to the failure of the board.
One factor was that the electronic device had a volume of air in it. As things heated up and cooled down, it acted as an air pump, pulling in air or water via the wire strands. The device had a "pigtail" of wire that connected it to the outside world. In retrospect, we should have used a bulkhead connector to avoid that sort of problem.... although there are potential problems with that too.

Ahhh... part of the fun of design is finding out all of the ways to get yourself in trouble!

Steve in Peoria

RGMN

That is the issue, isn't it? The bicycle electronics area is a niche and there are no good solutions. I've often wondered why no one has tried taking a Di2 extension cable and cutting it half, using the cut ends on the permanent connections and the Di2 connector as the disconnect point. We know the Di2 connectors survive on a bike, and are nice and small, but I don't have a clue if the wire size inside them would be adequate for the current being run.


Nice to see someone has fought the same issues. Sometimes I feel like I'm the only one who's seen them. A couple of engineers at my company recently retire. Them, myself, and 1 other engineer were the corporate subject matter experts on connector issues. I'm now trying to train up a few others but I doubt I'll get it done before I depart the company in December. I feel sorry for the engineer that will be left. I had a engineer who couldn't believe that water would actually wick thru a wire. I told him he either needed to vent his electronics housing or use blocked wire to stop the water ingress issue he was seeing. He didn't listen and a customer experienced some spectacular failures due to water ingress into the electronics. We are now in the middle of a recall to replace 12,000 units with units that have a GoreTex vent.

Pop N Wood

Why not use the waterproof connectors I referenced in post 21? don't know if they are rated for submersion but the automotive industry has been using metri pak connectors for decades now. The definitely eliminate the need for separate boxes for protection while the positive retention connectors eliminate the need for external velcro tie downs.

Pigtail connectors and the heat gun solder connectors seem like an excellent DIY solution for people with no soldering skills.

2_i 

There is no strain relief. They tend to be made for thicker wire than I would normally use on a bike. If you want to be able to replace components, the price seems to go up by an order of magnitude.

sweeks

These are also called "silicone" grease. I have a tube I bought at Radio Shack years ago and still have plenty left. I use it especially on the connector to my dynohub. Winter salt can be hard on connections.
Silicone Greases

steelbikeguy

I've been in a couple of positions where I seemed to be one of the few who had enough experience to avoid doing dumb things (or at least smart enough to not do dumb things two or three times). People would come to me, looking for advice on their problem, and after answering the same question a couple of times, started writing up some design guidelines. I had seen similar guidelines earlier in my career, which contained a lot of the lessons that were learned the hard way.

I hope someone is updating the guidelines that I've written, but I don't expect it. There hasn't been much respect for technical knowledge for quite a while. People seem to think you can just hire a new, cheap engineer and they somehow know everything. Well, even if management never really appreciated some of the wise engineers that helped train me, I know that I appreciate them!

Steve in Peoria

boomhauer

Well. It's been a year. Soldering wires together then heat shrink worked. I ride my bike daily in all kinds of weather (but not in a coastal area). This is the first time I haven't had to fiddle with my connections for a year.

I wanted a removable connection from the dynamo to the lights and the Sinewave phone charger but figured that if I really needed to remove wires I could just snip them and start again.
I've tried various connectors over the years and covered them with grease but they always seemed to have some issue. Probably over sensitive to the low voltage involved in a dynamo hub.
All the responses were very enlightening (being an engineer myself working with control systems) .
I feel like a semi-idiot for fooling around with aluminum connectors before.

Trevtassie

Been using these for a few years now, cheap and work well. https://www.ebay.com/itm/171866680184

2_i 

Depending on a bike I have used the Schmidt coaxial connector or variants of 2.8mm spade connectors. Off the cuff : One should not use the dynamo voltage as an excuse for poor workmanship.

Litespeedlouie

Stuffing a connector with Nyogel 760G seems to be what car makers do to their connectors, so makes sense to me. I just use the stuff on flashlight threads. Nyogel is incredibly expensive if you try to buy it by name, but you can get the exact same Nye product rebranded as Ford/Motorcraft XG-12 electrical grease for about $15 for a 3oz tube. It's a synthetic PAO grease, not silicone.

The previously linked article about dielectric greases:
https://support.newgatesimms.com/cho...tor-lubricant/
sounds like Nye-speak, but also interesting is their advice to NOT use silicone electrical grease:
https://support.newgatesimms.com/not...al-connectors/