Rear light with brake warning.

[Blue Hills]

I had a B&M dynamo back light that claimed to go brighter when I braked, but I have no idea if it actually did.


I've had one of those in my porch for over 15 years. Never given me any trouble. Comes on at dusk and stays on for a few hours then goes off.

I was referring to rear lights on bikes - sorry, I don't trust auto for such a thing, though some of those (too) clever lights do have a manual option. Then I'd just pray that the manual function wasn't over-ridden by a bit of plastic gimcrackery that reckons it knows better than me whether it's light or dark/where my arse is.

By the by, I would suggest that folks always use two back lights - I have been known to use three.

 

[keithmac]

I'm amazed at all the techno-hate. I'll go back to my paraffin lamps asap.

It's never dropped out of manual mode, it's never turned itself off, it's just been a good light.

Have you ever paused to think how dangerous a drive by wire throttle is in a car?, I must sell mine asap just in case there's a 1 in a billion glitch in the coding..

 

[Blue Hills]

I'm amazed at all the techno-hate. I'll go back to my paraffin lamps asap.

chill - stop staring at the strobe.

 

[T4tomo]

I usually shout "slowing" when circumstances dictate. Its quite foolproof.

 

[Ming the Merciless]

I'm amazed at all the techno-hate. I'll go back to my paraffin lamps asap.

I’m amazed that some people get into the you either love it or hate it. Implying there’s some strong emotion involved. I think most of the responses are more of a meh, take it or leave it.

The question is “Does a bike rear light that goes brighter as you slow make any difference over a good rear light of constant brightness?”. If it does make a difference, what is that difference? Of course the answer will be speculation as there will be no actual data to say either way. The technology in use is of no concern as long as it works reliably.

 

[simongt]

This reminds me of the direction indicators that were marketed in the '60s. Chrome casing with a yellow arrow facing each way and mounted somewhere suitable on the back of the bike. Battery operated, but with the power of battery thingys back then, didn't really stand out. As you can imagine, not many were sold - !

 

[cougie uk]

See sense lights have been doing this braking thing for years already. And made in Northern Ireland too.

I remember someone showing up at the local bike cafe with an analogue version years ago. When you braked red flaps would deploy. I think they were normally held back by small springs or something. That technology didn't take off.

 

[lazybloke]

Have you ever had to stop suddenly when riding on a road, and not been the slightest bit concerned that the driver behind might just plough into you?
An automatic brake light function on a rear light is a FAB idea.

Yes I might not prevent that scenario. Yes it might go wrong.
But I've seen these things in use and they work brilliantly. I want one.


There are lots of things we do for a small chance of a good outcome.

 

[figbat]

I picked up one of these Facebook advertised rear lights recently and coincidentally used it for the first time today. You can select a mode (flash rate, solid, bright, whatever) and it includes an accelerometer-induced brake light, which you can test by simply tilting the light. The same sensor also activates an auto on//off function, so if it doesn't move for a little while it switches off and then comes on again when you move it.

Whilst all of this is very clever, my main reason for buying it was the sleek design and saddle rail mount, putting it up as high as it'll go, not obscured by the rear mudguard and not competing for space on the seatpost. The light unscrews from the mount for recharging by USB.

 

[Ming the Merciless]

Have you ever had to stop suddenly when riding on a road, and not been the slightest bit concerned that the driver behind might just plough into you?
An automatic brake light function on a rear light is a FAB idea.

Yes I might not prevent that scenario. Yes it might go wrong.
But I've seen these things in use and they work brilliantly. I want one.


There are lots of things we do for a small chance of a good outcome.

No because they will be able to see you are stopping quickly and brake accordingly. Their brain will not associate a slightly brighter rear light with that act. If they are too close and / or not paying attention. Then it’ll make no difference

 

[C R]

No because they will be able to see you are stopping quickly and brake accordingly. Their brain will not associate a slightly brighter rear light with that act. If they are too close and / or not paying attention. Then it’ll make no difference

It isn't just slightly brighter, mine is about four times brighter than in normal operation.

 

[Ming the Merciless]

It isn't just slightly brighter, mine is about four times brighter than in normal operation.

Either way. I just can’t see it making any difference to a rare circumstance anyway.

 

[GuyBoden]

I got a similar circular design a few years ago. After each recharge, the battery lasted less and less time, then I think it died.

 

[lazybloke]

Either way. I just can’t see it making any difference to a rare circumstance anyway.

In my 33+ years of driving I've been hit by a car 6 times. 5 of those I was stationary with the handbrake on - so no brake lights visible. I've also been hit when on a bike (although that was side on).

Maybe these experiences have given me an elevated perception of risk from other traffic, but the result is I feel in danger when I'm on busy roads, particularly when I'm stationary with no visual cues to the drivers behind me.

I think we will agree on several things:

Motorists can be unobservant.​

Motorists can be numpties.​

Motorists occasionally drive into other road users.​

I don't know if having an automatic brake light on a bike would make any actual difference to my safety whatsoever, but it's fact drivers are conditioned to respond to a brake light in front of them, so I see no harm in having such a light on a bike.

In my experience this risk is real, not just perceived. It's happened before, it'll happen again. Just maybe one of these lights will help me avoid a collision in future.

We don't need to argue about the stats. I'm telling you I'd be happier with a brake light. I assume you can accept that!

 

[Supersuperleeds]

I had a B&M dynamo back light that claimed to go brighter when I braked, but I have no idea if it actually did.


I've had one of those in my porch for over 15 years. Never given me any trouble. Comes on at dusk and stays on for a few hours then goes off.

@tallliman has a rear dynamo light that has a brake light, it definitely works.