Can you run a rear dynamo light from any Busch + Muller front dynamo light

[Jdsk]

I have just moved my dynamo to another machine and considered using the SON coax, but instead used the B&M twin core (I had both available) because it lies flatter along the frame for securing.

As above I prefer twin core for the same reason.

Fragility of the smaller wire should not be a problem if you install it well.

My idle speculation about fragility wasn't about current offerings from B+M or SJS but about the smallest wire that might still work electrically with the most efficient LEDs (or whatever succeeds them).

Jonathan

[simonineaston]

Most of my B&M front lamps, but not all, have wire tails for fitting a rear lamp.

[Jdsk]

But I've got a fairly straightforward question which is can you run a rear dynamo light from any of the B&M dynamo headlights or is it only specific ones? And if it's only from specific ones how am I meant to tell which ones from the B&M website because I'm reading the descriptions but I can't find any reference to this.

How about suggesting the models of front and rear lamps that you're considering, and we then look specifically at those?

Jonathan

[John_S]

Hi All,

Many thanks for all of the replies above which are much appreciated.

Also thanks for Andrew_s for advising that I want to be looking for the lights that have either 'Senso' or "N" in the model name because that's helped a lot as well as looking at the pdf instruction manuals which has helped unlock some of the B&M range of lights which was previously baffling me!

Howvere one thing has just put a potential spanner in the works of my plan. Because my son's bike has metal forks I'd sort of just assumed that it would have a threaded bolt hole at the top of the forks where I could mount the dynamo. However I've just gone and checked it and it doesn't have a bolt hole on the front of the forks only the rear of the forks which is going to make mounting a headlight in my preferred position on the forks a pain (and it makes my assumption that it would have a bolt hole at the front a bit stupid in hindsight).

Instead I could consider the B&M handlebar mount which wouldn't have been my first choice but I wondered if anyone else has used this B&M mount and has any advice on whether it works well or not?

https://www.bumm.de/en/products/mehr/produkt/470lh.html?

Thanks again.

John

[Jdsk]

Haven't used that one, but we have headlamps on extension bars, fork crowns, and halfway down forks. You can also use brake pivots.

I'll have a look at some options... can you add some photos showing all the holes and bosses and the fork crown and the stem and bars?

Jonathan

[andrew_s]

There are a variety of options.
The light beam is designed for fork crown mounting, so something that allows the light to be positioned below the handlebar is best.

https://www.sjscycles.co.uk/lighting-sp ... p-bracket/ (cheaper than the similar B+M version, surprisingly)
https://www.sjscycles.co.uk/lighting-sp ... handlebar/
https://www.sjscycles.co.uk/lighting-sp ... ht-holder/ (replaces a headset spacer)
There are also headset spacer handlebar extensions, and I've got a mount that fits via an upside down star nut or bung in the bottom of the steerer tube (I'll see if I can look up where I got it when I get back to my laptop)

[EDIT] it's called a "SON Headlight Bracket for Suspension Forks for B&M Lights", came from St John Street, but no longer listed

[PH]

Because my son's bike has metal forks I'd sort of just assumed that it would have a threaded bolt hole at the top of the forks where I could mount the dynamo. However I've just gone and checked it and it doesn't have a bolt hole on the front of the forks only the rear of the forks which is going to make mounting a headlight in my preferred position on the forks a pain (and it makes my assumption that it would have a bolt hole at the front a bit stupid in hindsight).
John

As long as there's some metal round it, just drill a hole to match the one at the back and put a bolt through. If it was safe to have a hole in the rear of the crown, I can't see why it wouldn't be at the front. I've done this a couple of times.
On a carbon fork that only had a threaded hole at the rear, I've seen someone use a U shaped bracket attached to that hole and passing under the crown.
EDIT - The website I linked to in my previous post also has a page on mounting
https://www.peterwhitecycles.com/light-mounts.php