Had to rethread my (Shimano) dynamo connector today, and wondered why the charger has been fitted with a stranded (instead of solid) cable. Strands make it fairly delicate to insert the cable in the connector, more likely to have a stray strand short circuiting the connection, and more likely to disintegrate under physical stress.

The usual reason to use a stranded cable would be to avoid sectioning under repeated flexing, which is irrelevant (or so it seems) for a dynamo cable.

Am I missing something?

---

Had to rethread twice so far, both times after removing the front wheel while packing the bike for travel, in a hurry - I disconnect the cable from the hub, but probably forget about the dangling connector which ends up being squeezed between the tire (2") and the fork. I'll probably try to install a small rubber band to hold the connector out of harm's way. If anyone knows about "best practices", I am all ears.

Stranded cable is more flexible and easier to use. Solid core cable is a PITA.

Are you talking about the wires that you insert into the dynamo from your light?

Solid is what you use if you need the wire to be stiff, and it's in an environment where there's no vibration or flexing. If there is flexing or vibration, a solid core wire will fracture quickly.

The more flexing, the finer you want the strands to be.

If you can make sure the wire isn't going to be subject to flexing at all, you might get away with using solid, but IMO there would have to be a good reason to do so.

And from the electrical conductivity standpoint, stranded allows for better current transmission than solid wire as it has more surface area, and the electricity actually travels along on the surface of wire not through the inside of it.

well, this is true, but only for very high frequencies. Not relevant for the frequencies generated by hub dynamos.

but otherwise, the advice to use stranded wire is correct. It's better for vehicles, due to its greater resistance to fatigue failures caused by vibration.


Steve in Peoria