Dynamo hubs

Are you powering anything else of the hub/Revo? When I’m running a red eye off the Revo i usually only get 2 leds until I travel at sustained 20/22kph. Setting off, around town or slower rides with the Red eye attached I’ll never get all 4 leds showing.

This is which a Shimano Alfine 6v3w hub, which should be the same output as SP8 I believe.

The output voltage of the hub is dependent on the load. It means roughly “6 volts when 3 watts of load are attached”. With nothing attached it’s normal to see very high voltages - sometimes 3 figures!

If I were troubleshooting the next thing I’d do is try to power the light off an external/bench power supply. If you’ve got anything in the house that outputs 5 or 6 volts regulated DC try touching the wires to that.

(Not for more than a few seconds as DC can overheat components designed for AC)

Tried with/without the redeye. I've used it extensively in the past and expected the light to take a while to warm up. I'm guessing either the LEDs have had it, or something's come loose/failed inside the lamp.

@grams that makes sense. I'll probably pop an email off to Exposure rather than dig out the power supply. They've fixed several lights for me in the past and rather not risk any further damage and a more expensive repair :)

I had exactly this (or thought I did) recently, so pinged an email off to them saying that only 2 LEDs were lighting up etc. Their response told me that the other 2 only light after a short while riding and they go off instantly on stopping, so it can give the impression that only 2 are lit. Their recommendation was to rotate the mount so you can see the face of the light whilst riding and go for a short ride in daylight.

I haven't done it yet but bits of their email might be relevant to you if you are only gauging whether the second 2 LEDs are working based on the standlight function or spinning the wheel by hand, which is not enough.

They also sent me a warranty/service form so I get the impression that they will be good about fixing it if there really is a problem, but I need to do the test first...

My B&M does that. Goes down to 2 lights when you stop to save energy, lights up again when you're going

Yep, got the same email. I'd done enough night riding before going away to know the top LEDs dim quickly and had tested that while riding to confirm the vertical LEDs weren't illuminating. I initially assumed the dynamo wasn't putting out enough then put off doing anything about the situation as I didn't want to unlace a freshly tubelessed wheel.

Posting the light back to Exposure tomorrow and hopefully find out what's up with it shortly.

Be interested to hear what they say if you don't mind, will do the test on mine this week too.

I'll post over in dynamo lights when I hear back from them :)

Anybody experienced the connection tabs of their SON hub creeping round in the opposite direction to the wheel?

For various reasons I'm running the wheel/hub but there's nothing cabled up to it. With both the TA and QR setups is creeps backwards, was worse with the TA. Event when TA tightened up a bit tighter than I would like...

Bit weird. Might try carbon grip paste or something.

I would say TA not night enough.
Or if it is tight theres an issue with the surface tolerance on the fork.

Photo

Thanks - I'm not using the TA fork any more (that's another story), I'll tighten up the QR a bit more. The QR fork hasn't been as bad for it, which I suspect is down to the metal dropouts.

Is it a TA hub using a QR with an adaptor?

Oh but it did it before with a TA fork to?

Edit: you said that already. Sorry.

Weird. I've never had it. Even if nothing connected. I'd email son

Yeah I'm using the Hunt adapter at the moment. It was way worse with the TA fork, probably half a revolution over a couple of hours ride. New frame arriving shortly so will get another opportunity to test using TA.

No, but my SP would do that if I didn't have the TA done up tight enough. There's some decent forces going on I guess with disc brakes.

Is the adapter getting in the way so that the fork isn't clamping down on the hub or something?

Braking force was my assumption, though the SON site suggests the dynamo can become “sluggish”.

Just took some photos in case anyone is curious. I’ve tightened to a Torque Wrist™️ 10Nm and will observe.

It’s not been anything like as bad with the QR adapter and this fork. Other fork I suspect was not made especially well.

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If it’s a through axle hub, SON do not recommend using adapters, the hub won’t be secured correctly and therefore the axle will rotate.

Son do provide a Son branded adaptor with their TA wheels though...

I may be mixed, I thought they don’t recommend, was pretty sure. Maybe it’s just with their axle... let me confirm tomorrow!

The adapter is SON branded, but supplied to me and designed by one of the guys at Hunt

I found this weird too - I have a SON thru axle and SON branded adapter, although I do think it doesn't feel as good as it should to ride. Just a bit noodly

Grand. Let me check my facts... either way, if it’s turning, axle/qr is not tight enough. Also, no grease to be used on QR axle / bolt through.

Also as I said earlier, with the QR adapter it's not too bad

My main reason for mentioning this on here is that I had the issue with the TA fork, and tried it with the TA tightened more than I would consider wise. As Skinny said, that could have been an issue with the fork. Since there have been other issues with the fork, I wouldn't be so surprised.

Aye.

Worth measuring the true OLN of the fork. And the hub to rule it out.