7

I am looking to purchase a dynamo hub, such as those made by Shimano, Son, Exposure etc. and a set of lights to connect to it.

What I want to know is if any dynamo light will work with any dynamo hub, if they have proprietary connectors or if there are connector standards that work together?

If not, are adapters available between the various brands?

Son connectors

Here is a picture of the connectors on a Son hub, which are not a standard I am familiar with.

2 Answers 2

10

Speaking in terms of past few decades to current generator hubs and lights, mostly they are interchangeable, with some qualifiers and exceptions.

Almost all current hubs and lights are based around 6 volt, 3 watt, and can all work together. Usually the deal is your hub is going to have its own connector type which it will probably come with, like the two-piece plastic plugs for Shimano or the spade connectors for Schmidt. Your light will either have an integral wire as in recent higher end B&M and Schmidt lights, or terminals for a wire with spade connectors, or in some cases a proprietary plug type with an included wire. It's going to be some type of two-strand wire regardless, which you'll then cut to length, prep as needed and connect to whatever kind of connector(s) the hub takes. Most lights come with wire but not all, and in some cases you'll have choices like getting the fancy Schmidt coax wire, which is excellent but a little more involved to prep.

There are some oddball 12v6w lights and hubs that won't play nice with others, and then there are some random things like the old Schmidt E6Z secondary light that would probably need some creative splicing to work with a Shimano plug, and there's probably some other miscellaneous exceptions. But the reason they're exceptional is that almost all of these lights are intended to be usable as upgrades or replacements on random bikes in the generator countries, and same deal with hubs being intended to drop in on existing bikes, so they're mostly very much intended to be cross-compatible.

1
  • Note the existence (at least in the past) of 6V 2.4W hub dynamos. I have one on my hybrid, and it drives a pair of LED lights perfectly well - but the front isn't a massively powerful one on any hub
    – Chris H
    Oct 14, 2022 at 14:14
0

I encountered a related but completely unanticipated problem with Supernova hub dynamo bicycle lights. I wanted to run a Supernova headlight with a Busch & Muller rear light. But my curiosity was alerted by strange wording on the Supernova website. Eventually, I discovered in their FAQ the dirty truth, that not all headlights and rear lights are compatible. Supernova dynamo headlights can drive a rear light, but with Supernova the tail rear light output is 6V DC, which so far as I know is compatible only with Supernova rear lights. Most dynamo headlights run off 6V AC and most dynamo headlights output 6V AC to an optional attached rear light. To the best of my knowledge, AC rear lights cannot run off DC. What I don't currently know is whether dynamo tail lights can be run directly off a hub dynamo, instead of indirectly via a headlight.

4
  • that's not really a dirty truth. It allows the rear light to be smaller, with just the LEDs in place and all the power conversion and regulation done in the front light. If you have a 6V AC rated rear light, you could run it in parallel to the front light. You may or may not then miss some features like standlight, voltage regulation, etc, depending on the specification of the light in question
    – Noise
    Oct 14, 2022 at 12:29
  • Supernova do indeed build their lights to be used as a pair. A dumb light built for AC will run on DC (they're internally rectified anyway), but the drive circuits of modern LED lights aren't dumb, so you may have symptoms like no standlight when you stop moving, but only as bright as standlight mode when you are. I saw this with my AXA front light recently, but my cheap rear light was OK (testing because my dynamo hub was being serviced and I wanted to see if I could power my lights off a battery)
    – Chris H
    Oct 14, 2022 at 14:11
  • Re: A dumb light built for AC will run on DC. IIRC, that is in direct contradiction of what B&M say about their dynamo headlights (e.g. a fairly typical B&M Lumotec IQ Cyo senso plus 175QSNDI [I checked]). They do not elucidate why. I haven't opened / destroyed one to check, or tried powering one from DC and I don't intend to. Most dynamo headlights are intended to run from a headlight, this protects the tail light from being over-volted and destroyed. Some dynamos may have inbuilt circuitry to limit the output voltage. But unless you know yours does for certain, it's a risk one takes.
    – Amoeba
    Oct 16, 2022 at 16:13
  • Further to my last comment, Spanninga say this on their website, in the description of a number of their rear lights, in this case the Lineo light): "The dynamo version of the LINEO should only be connected to the dynamo (3W) via the headlamp and not directly to the dynamo (risk of overvoltage)." So direct connection of a dynamo light to the dynamo is a risky activity.
    – Amoeba
    Oct 17, 2022 at 6:52

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.