A bit pee’d off at the moment. After spending what felt like weeks looking into Hubs and lights. I’ve finally got everything and put it together. SP PD-8 dynamo hub with a B&M Luuxos IQ2 U. But it appears to be shit…so something must be wrong! Two main problems are:
– The light only stays on for about 2 minutes and then switches its self completely off and doesn’t turn back on again unless I hold the button for 2 seconds.
– The light is very very dim, (not very bright) looking at it it looks like just 1 or two leds are switching on, even on full beam it hardly shines.Looking at review photos its about 5% as bright.

I live in Sheffield so on the way to work which is downhill for about 15-20 minutes, this should be plenty to get a good beam…

So what could I have done wrong? Any one else got one and can confirm its supposed to be really bright.
Thanks

It sounds like your dynamo is charging the light just enough to get the stand light to work and once the capacitor discharges out go the lights. However, Might be worth double checking all electrical contacts first and also double checking you have your positive and earth connections the correct way around (at lamp and hub). What type of bracket do you use for the lamp? It don’t know whether the lamp might earth itself via a metal bracket to your frame. Finally, I’ve met people with problems who didn’t realise that there are 3 modes on some dynamo lamps (easy to see if you look closely on the switch).

Once sorted they are great, I run Alfine dynamo hubs on two bikes and will soon build one for a fat bike.

Good luck

Hi
On the hub itself does this have a positive and negative as there was nothing in the instructions or written on which way round this was. So it the left or right positive. I’ll try swoping the wires around.
Using the metal bracket connect to steel forks.
The blue light comes on the switch and should mean full beam, its gets brighter but not a lot.

Hub is a PD-8 not PV as its disc, if that makes any difference.

hub generates AC and IIRC there’s no earthing so it shouldn’t matter.

I have the cheaper light (60 lux?) and the standlight lasts well, also it puts out ~250 lumens (to my eye)

I have to say I don’t think there’s much you can do wrong. Does yours have the separate stand/day-light? Mine doesn’t and only has 1 LED.

Have you got the input and output connections the right way round? Should be 2 sets of plugs on the light – input for connecting to the dynamo, and output for a rear light.

Some dynamo hubs are earthed to the frame/fork, not sure about the SP hubs. Should be an earth symbol on the little plastic connector.

Hi. Sorted cables were touching in the connector. Wheel moved and light get brighter.