Author Topic: B&M Cyo standlight  (Read 330 times)


B&M Cyo standlight
« on: November 20, 2020, 04:28:55 pm »
It's been about a year since I cycled in the dark but I'm sure that it used to stay lit up at stops, not just switch to the small emergency LEDs.  I wonder whether it's a capacitor error (again!) it would be the third time I make a return to ROSE (poor things).

If it *is* another issue with the light it shows a massive downgrade in quality from B&M - who's the alternative?
[/I could be wrong]


  • Timelord
Re: B&M Cyo standlight
« Reply #1 on: November 20, 2020, 04:33:17 pm »
If it's a Cyo T, with the separate 'be-seen' LEDs along the bottom, they're what gets used for the standlight.
Careful, Kim. Your sarcasm's showing...


Re: B&M Cyo standlight
« Reply #2 on: November 20, 2020, 05:53:08 pm »
Oh, allright then.  They seem very minimal (barely enough to be seen by) and I obviously recall incorrectly that there was a period of actually staying lit before switching to *vague glow*.

[/I could be wrong]

Re: B&M Cyo standlight
« Reply #3 on: November 20, 2020, 07:26:50 pm »
in the manual it says;

plus (standlight function)

The standlight function is always ready for operation. It is completely maintenance free and works without batteries or rechargeable batteries. This is how it works: A minor amount of the energy generated by the dynamo is stored in a capacitor while riding. The capacitor is already fully charged after riding for about 3 minutes. While standing, the stored energy is supplied to two of the lower LEDs of the headlight, so that these keep on shining.
The standlight function can be turned off by switching to the "0" position. The remaining capacity is stored in the condenser for several days so that the headlamp can be used as a light source, e.g. in a dark cellar, when set to the "S" or "T" position.


Re: B&M Cyo standlight
« Reply #4 on: November 20, 2020, 08:13:08 pm »
I think it's deliberate design.  The 'main beam' is aimed at the road to illuminate and avoid dazzling other road users.  The 'daytime' LEDs are aimed horizontally to hit driver's eyes.  The standlight exists mostly to keep you visible, so it powers the latter?

Re: B&M Cyo standlight
« Reply #5 on: November 20, 2020, 08:15:50 pm »
I do agree the standlight power doesn't seem particularly generous, mind.

Re: B&M Cyo standlight
« Reply #6 on: November 23, 2020, 06:51:27 am »
It can't be.

Assuming the main beam takes 3W then it would take a long time to trickle-charge a (huge) capacitor ready to run the standlight.  I calculate you'd need a 120F capacitor, which is larger than most headlights.

Rear lights do accumulate standlight charge quickly and stay on at full brightness, but LED ones are only about 0.2W so everything can be much smaller.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.