Zen Katana E-bike Light (DOT compliant)

Ravi Kempaiah

Well-Known Member
A powerful and integrated light is a must-have an E-bike, especially on bikes that reach 28 mph or 45kmph. Both for the safety of the rider and the vehicles coming from the other side.
People don't expect a bicycle rider to go fast; being seen by other riders and vehicles is extremely important to avoid accidents.
We are working with a leading light manufacturer to design a new E-bike light that is powerful, light, and very appropriate for E-bikes.
Some key merits :
  • The light pattern is DOT compliant i.e., has a sharp cutoff so as not to blind the oncoming traffic. This is an issue with generic lights because the dispersion is so wide that it is very annoying for the oncoming traffic.
  • More importantly, the light is certified so that it has no electromagnetic interference with other devices such as GPS, phone, or the E-bike controller.
  • In high beam, Supernova M99 Pro draws about 32W and that's a lot of power. (On a 640 Whr battery, that's about 5% loss or ~6.5% loss if you are using 500Whr battery). The Zen Katana uses 14W even under high power mode, which helps with minimizing power loss.
  • The color temperature is picked such that it produces less fatigue on the eyes and is suitable for enduro riding at night.
We will have low beam/ High beams along with very bright daytime running lights.
A lower-spec version of this will also be made available at $99 but that will be in the summer of 2021.

Supernova M99 Pro retails at $ 450
We hope to price this very competitively at $230ish for retail purchase (open to all)
Here are the comparisons with Supernova M99 Mini Pro-45.

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Johnny

Well-Known Member
Ravi, as you know I have the M99 pro. It has a very good spread and bright. Definitely sufficient for almost any kind of riding. I rode a lot at night and cars coming from the side roads realize that you are coming their way.
Now is it worth 450? I don't know. Given that 1000lumens cree leds are out there and used even in $30 bike lights the brightness can certainly be matched for a lot less.
The optics(mirrors especially) will surely add quite a bit to the cost still $450 is a bit high. Also supernova blinds people and quite taxing on the battery. Still it is a great addition to any bike and imo improves safety significantly.

It is hard to make an accurate assessment of the Zen light from the photos. I would think the brightness is very good. maybe as good as m99. But the vertical spread looks a bit too narrow. Does it illuminate the road surface well? At night it is quite important, to maneuver around holes, cracks etc. , especially at higher speeds. I can not make it from the photos.
 

Ravi Kempaiah

Well-Known Member
I would think the brightness is very good. maybe as good as m99. But the vertical spread looks a bit too narrow. Does it illuminate the road surface well?

Of course. It is just as bright as the M99 Pro. You will be surprised how bright it is.
Because the photo was taken in a closed room with limited space, the beam looks compressed on the wall but on an open road, it spreads out quite well and long actually.
It is just not about the cree LEDs but also, the quality of the lens, thermal management when run for hours on end, the electromagnetic shielding to minimize interference with other electronics.
Keeping those LEDs running at 1500 lumens without hitting thermal bottleneck is not trivial.

As you can see from the test data below for a light that doesn't thermal management built-in, it leads to loss of power. We will do a full review with video in about 3 weeks comparing different lights.

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Johnny

Well-Known Member
It is just not about the cree LEDs but also, the quality of the lens,
That is why I mentioned optics. (Back in the day when I was taking an Optics course one of the things that the professor mentioned was "Although the math is easy, manufacturing a good lens or mirror can be very expensive so they take shortcuts ", I don't know how things go these days)
-I can see the cooling fins on the back of the light so it should have no problem with cooling.
So again I am sure it is just as bright and doesn't have any thermal issues.
-The mid section is bright so I am also certain that the long distance illumination will be good.

As you said it is hard to assess the spread in a room. Assuming that you put both lights at the same location if you look at the legs of the stand on the left while it is illuminated well by m99 , it seems a bit under illuminated with the zen light. Don't get me wrong, It may still be very well lit.

When you have the time you may want to take a couple of photos at night outside that should demonstrate the capability of the light even more.
 
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FlatSix911

Well-Known Member
Region
USA
City
Silicon Valley
A powerful and integrated light is a must-have an E-bike, especially on bikes that reach 28 mph or 45kmph. Both for the safety of the rider and the vehicles coming from the other side.
People don't expect a bicycle rider to go fast; being seen by other riders and vehicles is extremely important to avoid accidents.
We are working with a leading light manufacturer to design a new E-bike light that is powerful, light, and very appropriate for E-bikes.
Some key merits :
  • The light pattern is DOT compliant i.e., has a sharp cutoff so as not to blind the oncoming traffic. This is an issue with generic lights because the dispersion is so wide that it is very annoying for the oncoming traffic.
  • More importantly, the light is certified so that it has no electromagnetic interference with other devices such as GPS, phone, or the E-bike controller.
  • In high beam, Supernova M99 Pro draws about 32W and that's a lot of power. (On a 640 Whr battery, that's about 5% loss or ~6.5% loss if you are using 500Whr battery). The Zen Katana uses 14W even under high power mode, which helps with minimizing power loss.
  • The color temperature is picked such that it produces less fatigue on the eyes and is suitable for enduro riding at night.
We will have low beam/ High beams along with very bright daytime running lights.
A lower-spec version of this will also be made available at $99 but that will be in the summer of 2021.

Supernova M99 Pro retails at $ 450
We hope to price this very competitively at $230ish for retail purchase (open to all)
Here are the comparisons with Supernova M99 Mini Pro-45.

View attachment 71340
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View attachment 71344
The beam cutoff line looks super sharp... well done!

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drewberz

Active Member
Kind of cool @Ravi Kempaiah if you did a light shootout, the way MTBR does theirs, but for e-bike specific lights.

Nothing trumps how lights perform in the real world though. These pictures look great but camera settings can make a huge difference.
 

Ebiker01

Well-Known Member
Seca 2500 with the 3cell battery is the ultimate ebike headlight. That or Lupine . It stops cars, Suv's , foxes , squirrels you name it ...
If the Zen would be made with auxiliary cells (like the 2 or 3 cell batt. for Seca) it could be pretty good for the price). But Seca also has outstanding warranty and service. I shorted a prior Seca headlight in a very heavy downpour ride , i got a new one in 2 days.
The brighter the light , the safer the rider is. Cygolight hotshot or Lupine for rear.
 
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Timpo

Well-Known Member
I absolute love the sharp cut off line!

If I could make a criticism though, judging by the picture, the high beam isn't that high.
If I'm using high beam, I'd like my high beam to scatter around like cars / motorcycles headlights.

Is there any way to fix that?
 

drewberz

Active Member
I absolute love the sharp cut off line!

If I could make a criticism though, judging by the picture, the high beam isn't that high.
If I'm using high beam, I'd like my high beam to scatter around like cars / motorcycles headlights.

Is there any way to fix that?
I know Ravi didn't say he was going for StVZO standards (Germany), but you also don't want the light too high to be blinding. Hard to say from this picture if too high/low.

 

Timpo

Well-Known Member
I know Ravi didn't say he was going for StVZO standards (Germany), but you also don't want the light too high to be blinding. Hard to say from this picture if too high/low.

But for high beam, I actually prefer the highest amount of lighting possible.

But for low beam, I agree, I think Ravi's sharp cutoff line is great, so that you don't blind people.

Although $230 isn't cheap by any means, it is much better than $450.
 

Ravi Kempaiah

Well-Known Member
@drewberz ,
Thank you for mentioning the StZVO certification process.

Especially in EU, S-pedelecs must have certifications for lights so as to increase the safety of all riders.
A modified infographic from that website is shown below to give a quick illustration of the scenario.

StVZO - Straßenverkehrs-Zulassungs-Ordnung or German Regulations Authorising the Use of Vehicles for Road Traffic is a popular name on the Polish market.
For many users, it indicates the lighting quality and that’s it. But what is StVZO really?

Besides the specifications regarding the power and construction of lights, two fragments are important for a road user, who undergoes these regulations.
  1. One - minimal lighting value of area 10m in front of the bike should be no less than 10 lux of light (10 lumens / m2),
  2. two - prevent blinding other road users. It requires a specific light construction and optimizes light use, as it lights up a road, not the passing trees.
E-bike headlight following StVZO regulations will have a beam pattern similar to the one shown in the first picture (example 1)
A light not following StVZO, even properly set will blind oncoming bikers (example 2)
Light not following StVZO and not properly set is oncoming biker’s nightmare (example 3).

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Ravi Kempaiah

Well-Known Member
so can a bosch system power it?

Of course.
We worked with the OEM to design a light that integrates into our Bosch bikes seamlessly. Bosch has 18W light output and even in Hi beam, Zen Katana uses 14W, leaving another 4W for rear lights and electronic horn.
To make it a very neat install, we will have an integrated stem + light mount.
 

Ravi Kempaiah

Well-Known Member
What about previous gen Bosch that only have 6w/12w available?

Bosch Gen 1 and Gen 2 motors until the year 2017 had 6V/9W light output.
Since 2017, Gen2, Gen3, and Gen 4 systems have 12V/18W output. In the diagnostic portal, 6V configuration can also be can enabled.
So Bosch E-bikes like yours (Haibike Sduro Trekking S 9.0) would be able to make full use of the light output (1550 lumens).
 

BlackHand

Active Member
Thanks Ravi, I realized after I posted that I was mixing volts and watts in my head. :)

Your light sounds like a huge upgrade from the 150 lumen / 50 lux Skybeamer that is stock on my Haibike.