Need help identifying mechanisms on spokes! Components for bicycle computer?
 

Hi all,
First post and looking forward to gaining lots of wisdom in these fine forums.

What is the purpose of the device (see pic at link below)? There are three, equally spaced on one side of the rear wheels spokes.
I'm guessing it's part of a bike computer system? Or perhaps some auto-shifting device?

Thanks for your help!

https://www.anony.ws/image/JRpp

If they slide on a spoke they might be centrifugal weights for an automatic shifting system.

That was my first guess but they don't slide at all? They are very firmly in place. Although, there is also a mounted plastic piece midway up the down tube which has 2 holes in it (presumably one each for front and back derailleur lines). There are blemishes on the seat stay (closest to the 3 contraptions) thou....so looks like something may have previously been mounted there?

No idea.

Probably magnets from some long-departed flashing rear light. The magnets pass a part of the light mechanism that acts like a generator and creates a pulse of electricity to flash the light.

I think you've nailed it. I have one like that mounted on my BoB trailer, but the magnet mount looks similar, not identical.

I sold and installed many of them years ago, but I can't recall seeing them for sale in the past decade.

I just removed them and they were highly magnetic....so also think you nailed it. Still confused by the "guide" mounted on the downtube...but i suppose that's where the electric wires may have lead through.

Anyhow, thanks everyone ! Looking forward to hanging on this forum but a little scared of becoming addicted!

You made no previous mention of a 'guide'.

The versions of the similar light I was familiar with were wireless - no bracket necessary.

I didn't mention a guide per-se but this:
"Although, there is also a mounted plastic piece midway up the down tube which has 2 holes in it (presumably one each for front and back derailleur lines)"

Said bracket could be for something entirely different. Weird Bike....Ridgeback Panorama set up like a beach cruiser with woven basket and all...riser mustache bars and a stem captain (analog clock one)

I think the one I have is over 15 years old.