This discussion has been locked.

You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Varia Tail Light brake light function

Former Member over 8 years ago

Is the Varia TL brake light function accelerometer-based or speed based?

Documentation does not say much, except manual saying that for the brake light function to work well, light should be mounted on fixed vertical surface, such as seat post. That might indicate the accelerometer-based function.

Does anyone have experience using it with Edge 25? Varia light support was supposedly included in latest firmware and I am wondering what controls are available during ride.

Thx!

0 Former Member over 8 years ago

After a brief search I've not been able to find any mention of a Varia "brake light" function in the user manual or anywhere else.
Where did you see it?

0 aweatherall over 8 years ago

I believe that the answer is accelerometer based. If you have an external speed sensor then you can test if it is speed based quite easily. Put the bike in a stand or on trainer without there being any resistance on the wheel (this assumes that the speed sensor is measure the movement of the rear wheel). With the rear light on (not flashing) and paired in a light network with the Edge spin the cranks so that the Edge is registering speed and then firmly apply the break to the rear wheel and see if the brightness of the rear light changes.

0 Former Member over 8 years ago

After a brief search I've not been able to find any mention of a Varia "brake light" function in the user manual or anywhere else.
Where did you see it?

Well, there are two references. Check it yourself: http://static.garmin.com/pumac/Bike_Lights_OM_EN.pdf

1.

Installing the Multi-Location Mount
1 Select a secure location to mount the taillight where it does not interfere with the safe operation of your bike.
NOTE: You can mount the device on your seat post, helmet, backpack, or other location. Garmin recommends that you enable the deceleration indicator only when mounting the device vertically on your seat post.

2.

Taillight Light Intensity Modes table specifies "Braking" intensity mode.

Then there's promotional video showing a guy on a road bike and when he starts to decelerate, the tail light turns brighter.

Video: https://www.youtube.com/watch?v=MYBr9U8h__s
Time of braking event: 1:00

0 Former Member over 8 years ago

I believe that the answer is accelerometer based. If you have an external speed sensor then you can test if it is speed based quite easily. Put the bike in a stand or on trainer without there being any resistance on the wheel (this assumes that the speed sensor is measure the movement of the rear wheel). With the rear light on (not flashing) and paired in a light network with the Edge spin the cranks so that the Edge is registering speed and then firmly apply the break to the rear wheel and see if the brightness of the rear light changes.

I would certainly hope so as I think that speed sensor would provide too slow feedback for this kind of application. Accelerometer would provide much faster reaction to deceleration.

On the other hand the promo video https://www.youtube.com/watch?v=MYBr9U8h__s (@ 1:00) shows guy on trainer, so there is no real deceleration that would activate accelerometer and yet the brake light works. So either the video is marketing mockup, or it's speed sensor-based.

If I had the light, I'd certainly test it. But I do not have it. I consider getting it so I'm trying to get more information from the field. Apparently not so many people actually have the light.

0 Former Member over 8 years ago

Ah, now I see, I didn't realize there was such a thing, I have the Varia Radar and there's nothing in that owner manual.

0 AgileHumor over 8 years ago

There is another thread on this forum here:
https://forums.garmin.com/showthread.php?353524-Varia-Radar-and-Edge-1000-8-30-How-is-the-deceleration-feature-supposed-to-work

Auto de-acceleration is the same as the "brake light" feature we were sold...but doesn't seem to be working.

0 fallingrock over 8 years ago

I find the Auto deceleration feature works fine.

I have my TL300 set to blink mode and, when I slow down, my Edge 1000 tells the unit to turn the tail light on solid.

david

0 AgileHumor over 8 years ago

I've tested it 25+ times on solid (actually using Auto) where it sticks on medium.

The garmin video states it actually should get dimmer at faster speeds (don't know about flash mode)...and get really bright on braking to contrast.

Will test it on flash mode today.

0 AgileHumor over 8 years ago

I did get this to work using my hand and swinging it. However, I can't get this to work on my bike as it's not a perfect front back (offset 30%).

I thought one of the videos I saw on youtube stated the brightening of lights we're based on the Edge. However, I appears there is an accelerometer in the tail light itself that controls the brake light.

0 Former Member over 8 years ago

I did get this to work using my hand and swinging it. However, I can't get this to work on my bike as it's not a perfect front back (offset 30%).

Offset should not matter. If the light is rigidly attached to the bike frame, then the same deceleration force is applied on the light independently of the offset. What matters is the orientation. Basically it should be mounted vertical and face rear so that the deceleration force is applied to the integrated accelerometer at right angle and deceleration is correctly recognized.