Thorn Cycles Forum

Technical => Lighting and Electronics => Topic started by: tt2cycletours on September 29, 2025, 06:14:08 PM

Title: Supernova E3 with B&M rear light?
Post by: tt2cycletours on September 29, 2025, 06:14:08 PM
Quick question.

My supernova rear light has broken (just the superbright middle LED). Will check to see if it is still under warranty. Very disappointing. How much do you have to spend for a bomb proof lighting system?

But, has anyone paired a supernova with a B&M rear light? I like their brake stop tech and the built in reflector. I can't see that receiving a DC supply rather than AC is going to be a problem for the internal electronics and suspect the advice is more about selling more kit rather than a real problem.

Also: some SON dyno hubs going for £100 on SJSC if you don't mind red!

Thanks in advance.
Title: Re: Supernova E3 with B&M rear light?
Post by: macspud on September 29, 2025, 08:19:41 PM
Have you got a link for those £100 son hubs? I can't find any on SJSC's website.
Title: Re: Supernova E3 with B&M rear light?
Post by: Danneaux on September 29, 2025, 08:41:37 PM
Quote
Have you got a link for those £100 son hubs? I can't find any on SJSC's website.
Yep!

NOTE: ALL SON DELUX SL MODELS!

Silver...
https://www.sjscycles.co.uk/dynamos/20-schmidt-son-delux-dynamo-front-hub-silver/?geoc=US

Polished silver...
https://www.sjscycles.co.uk/dynamos/20-schmidt-son-delux-sl-dynamo-front-hub-polished/?geoc=US

Black...
https://www.sjscycles.co.uk/dynamos/20-schmidt-son-delux-sl-dynamo-front-hub-black-anodised/?geoc=US

Red...
https://www.sjscycles.co.uk/dynamos/32-schmidt-son-delux-sl-dynamo-front-hub-red-anodised/?geoc=US

Best, Dan.
Title: Re: Supernova E3 with B&M rear light?
Post by: mickeg on September 29, 2025, 09:38:44 PM
It is my understanding that the way that the B&M brake light works is by sensing the slower frequency of the AC circuit as you slow down.

I think that the Supernova sends DC to the taillight, thus not AC, so electronics that are sensing the frequency of AC are not going to work so well.  And I think that there is no standlight in the Supernova taillights, the standlight capacitor is in the headlight.

If I am right, a B&M taillight would work and the standlight would work too, but the brake light won't.

Everything I wrote above is based on memory, I can't cite a reference for any of that.  I have never used a Supernova.  If you have a multimeter, you should be able to measure if the circuit to the taillight is AC or DC.  If it is AC, then maybe the brake light would work?

I have only used AXA and B&M headlights.  And those have worked with B&M, Spaninga, and XLC taillights.
Title: Re: Supernova E3 with B&M rear light?
Post by: PH on September 29, 2025, 10:31:20 PM
Quote
Have you got a link for those £100 son hubs? I can't find any on SJSC's website.
Yep!

NOTE: ALL SON DELUX SL MODELS!
A bargain if someone has an SL rim brake fork.  I suspect that's going to be very few people.
Title: Re: Supernova E3 with B&M rear light?
Post by: PH on September 29, 2025, 10:33:54 PM
But, has anyone paired a supernova with a B&M rear light? I like their brake stop tech and the built in reflector. I can't see that receiving a DC supply rather than AC is going to be a problem for the internal electronics and suspect the advice is more about selling more kit rather than a real problem.
I thought about it when my rear Supernove light went the same way, but Peter White who is my guru for all things dynamo says it won't work.  You lose the standlight, the light flickers, then is likely to go pop.
Title: Re: Supernova E3 with B&M rear light?
Post by: macspud on September 30, 2025, 04:36:00 AM
Quote
Have you got a link for those £100 son hubs? I can't find any on SJSC's website.
Yep!

NOTE: ALL SON DELUX SL MODELS!

A bargain if someone has an SL rim brake fork.  I suspect that's going to be very few people.

Thanks Dan 🙂👍

Ah, you're right PH, they're of no use to me 🙁