Are dynamo hub plugs interchangable between brands?

[steve216c]

As this would have gone off topic on another thread- I started a new one thanks after mickeg got me wondering.
This might be useful as reference for anyone (like me) who has more than one brand of hub dynamo available and who might potentially want to swap out a front wheel with a different brand and who doesn't want to worry about compatibility and if they might need to faff around with re-cabling the plug.

If you have trouble finding a wiring plug to plug into the hub, SP and Shimano hubs are nearly identical.  I use them interchangeably.

For reference, I currently have 7 working hub dynamos of different models/brands at home.

I sold a guest bike early on in the pandemic which had an unbranded dynamo with single spade connector at the hub, with the frame carrying the opposite charge. This was NOT Shimano compatible for sure.

My wife has a very early Shimano hub dynamo with a similar one pole tab on the hub that predates the current fitting standard and had second cable attached to washer on the axel. Not standard, but has and is still working well for years. It came with cables and a handlebar mounted switch for turning lights on and off.

The other ones are a mixture of brands/models, and all seem to work fine with the Shimano plug.

1) MTB- cheapish unknown (Chinese?) brand which had different looking rubberized molded plug, which when it perished/broke I found the Shimano plug fitted fine. This was a relief as I was worried I might not be able to find a proprietary plug for a brand I've never seen anywhere else and where the shop I bought it from no longer exists.
2) Shimano more recent models all with same 'standard Shimano' fitting on hubs I have in household: DH-C3000, Inter L HB-NX32 and DH3N72
3) SRAM i-light (likely to be a rebadged Panasonic) also fits 'standard Shimano' fitting
4) SP/Shutter Precision PD-8 which, as I already discovered but as Mickeg confirmed too, also work with the 'standard Shimano' fitting

This might be useful info for anybody who might feel bound to one brand because of the cabling already on the bike, who might be unaware of being able to switch brands/wheels without worrying if they need to rewire. I have winter spikes mounted on one hub dynamo, and can easily switch between regular tyre and winter tyre on the front quickly knowing both hubs have compatible fittings for Shimano.

Not sure if SON or other brands fit. But hopefully someone in the forum can confirm from experience if they also work with Shimano fitting plug.

[PH]

Not sure if SON or other brands fit. But hopefully someone in the forum can confirm from experience if they also work with Shimano fitting plug.

The SON is very different, there is no interchangeability.
Which is a shame as I'd like my charger to fit on all three types of hub I have - SON, SP, Shimano - I really ought to get one that doesn't start with a "S"
At the moment the charger has a Shimano fitting which also fits the SP,  the easiest connection to the SON would be spades to block, which I may get around to one day.

[mickeg]

This is specific to only how the wires are connected to the hubs:

Shimano and SP.  I think you can treat Shimano and SP as the same, although I believe that all newer Shimano hubs have one connection grounded to the fork and SP does not.  My first dynohub was an SP that I bought in 2013, I moved that around between three different forks.  For simplicity I had wires and a plug zip tied to the three forks.   At that time nobody sold an SP in USA (I ordered mine from Taiwan), so I was quite happy to discover that the Shimano plugs were interchangeable with it as I could buy those connectors.

Son.  Clearly looks different and I have never used one.  Now they also make one that uses each fork blade as a connection, you need a fork that is built for it.  So, there are two Son current standards.

Panasonic. The plug looks similar but different from the SP and Shimano ones.  I have never seen one, thus I am clueless.
https://www.somafabshop.com/shop/product/panasonic-dyna-hub-6v-3w-qr-rim-brake-4420

Sturmey Archer.  I have no clue if the plug is the same as one of the others or not.
https://www.sturmey-archer.com/files/catalog/files/170/MANUAL%20-%20DYNOHUBS.pdf

Grounding to the fork.  Since my first two hubs were SP, I had learned that the hub was not grounded to the fork.  Then I got a great deal on a used wheel with a Shimano hub, and it took my hours to figure out that my hub and my light were both grounded to the fork, but with wires reversed it did not work.  Thus the hub worked on one bike but not on another.  That was how I learned that Shimanos are grounded to the fork.  The link to Sturmey Archer above, the hub connection looks very similar to Shimano, I suspect that it is also grounded to the fork.

Vintage.  And of course anything vintage could be different.  The Sturmey Archer hubs that I worked on in the 70s when I worked at a bike shop are clearly different than the current ones.

***

I am not researching this further, anyone else that wants to, go ahead.  Of these, looks like one does not start with an S for PH.  A few other misc notes:

Anyone that is trying to figure out if they should get a dynohub or not, they usually are not sold with a skewer. 

The ones I bought new, I built up the wheels so they were quite inexpensive because the price difference between a complete wheel with or without a dynohub is only the cost of the hub minus the cost of the regular hub.  But, if you are looking to upgrade and get a new wheel, that is when they get much more expensive.

So far the transition to through axles is slower for dynohubs than for frames and derailleur hubs.  I built up another dynohub wheel last spring, I considered futureproofing it by building a through axle hub with quick release converter, but it was much more expensive than a conventional hub, so that is what I decided to build.

Since dynohubs are mostly used for lighting, if anyone is interested I documented how I wired my rando bike for lighting on a different forum, at this link.
https://www.bikeforums.net/electronics-lighting-gadgets/1228845-wiring-up-dyno-powered-lighting-system-usb-charger.html

There was an article almost a decade ago that provides some very good info on some of these hubs if you are interested, at:
https://www.cyclinguk.org/sites/default/files/document/migrated/publication/feature-hub-dynamos.pdf

[Andre Jute]

The SON and the Shimano plugs are different, not interchangeable.

However, the SON, which is the way-off-outlier here, is pain to plug in in broad daylight in your workshop, never mind on a dark rainy night by the light of lightning on a road without adequate runoffs but heavy truck traffic and your mother-in-law on the phone to demand why you're late for dinner.

So it is common for SON installations (and even Shimano installations because in the wet that Shimano plug gets slippery and it is pretty small) to break the wire a few inches above the connector, leaving the bottom section long enough to make an open loop hanging underneath the connection when plugged in. At the other end put whatever flavor of connectors you favour at the cut. The wire going to the light, permanent, is tied to the tine of the fork, the short section that goes to the dynamo is left plugged in and not otherwise tied to anything; it stays with the wheel when you swap wheels. If you do this for all your hub dynamos and use the same connectors and orientation of connectors, you have a whole interchangeable wheel scheme.

Some details: If you solder the connectors on one wire as male to female and on the other as female to male, and do this consistently for + and - wires so that you can swap them by feel, you can't make a mistake, though a mistake won't do much harm and is easy to rectify. You can arrange water-proofing by a piece of electrical shrink-wrap tube of a large size, long enough to shrink watertight onto the wire coming down and to hang unshrunk over the bottom plug.

Dan published a photograph of his usual very tidy installation that you can search for (which is what I say when I failed to find it).

Also a useful post from John Saxby, complete with photograph, at
http://thorncyclesforum.co.uk/index.php?topic=13632.msg103457#msg103457