• 05-24-2015
    16 Attachment(s)
    Vicmax A8 Bicycle light Partial Tear-down & Impressions
    This is a light that I got from Amazon.
    Attachment 990774
    Amazon.com : Sanzo 10000LM 8x CREE XM-L T6 LED Head Front Cycling Bicycle Light Lamp Headlamp Bike for Running, Hiking, Working, Jogging, and Emergencies Bike Bicycle Headlamp Headlight : Sports & Outdoors

    If you check that link, you'll see that I was fairly surprised to see what showed up in the mail. The pictures show a circular light. I was expecting to get a something similar what Archie got here: http://forums.mtbr.com/lights-night-...ew-872692.html

    But this is what showed up:
    Attachment 990776
    Lookin more carefully at the product description, it's listed as 8x XM-L T6 LEDs, but you can see from the picture that what I got was XM-L2's (I think, let me know if otherwise). This was a set/kit that came with cheapo chinese battery (6-cells!), cheap-o charger, head mount, 2 rubber band for mounting, a cheap-o 5-LED tail light, and a reflective leg band (for pants). All in all, a pretty good haul for less than $20! (19.77).

    The light is very bright (I have no way of measuring light output). I can only compare to my ss x2. The A8 is definitely brighter than the x2. The beam pattern is very flood-y. This thing just spills light all over the place. The x2's hotspot outreaches the A8.

    I'm just going to post all the picures I have of it:
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    The button on the back lights up green. It might change color when the battery gets low? I'm not sure because I charge up the pack before each ride. I have not seen it change.

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    It has a blue "o"-ring on front and back.
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    Six philips-head screws on the back.
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    Four on the front.

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    All 8 LEDs on one plate. It seems to be seated flush against the solid frame with some white paste (thermal?). The thermal situation seems good. It only gets lukewarm when out riding, but almost untouchable when still.
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    A few more pics of the board/driver for those of you who know of these things.

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    Might be hard to see in the pics, but the mount has some rotational play/wiggle to it. I assume there's a loose screw under that pad/gasket, but I don't want to peel it off to find I'm wrong. Also, having that little wiggle is actually a bit useful for manipulating the light when there is oncoming traffic. I'm always worried about blinding people with this thing.

    This thing is a tank of a light. Someone must have thought, "If 2 LEDs are good, and 3 LEDs are better, then 8 LEDs must be the answer to all of the world's problems!" It is indeed bright, but it just seems like it'd be 10 times better if that light were more focused/directed.

    The combination with a more spot-y helmet light works pefectly, though.

    Attachment 990794
    I don't know if I did it right, but I used the included head mount and just stretched it around my helmet. I wanted to mount the battery pack lower, but there just weren't any options along the midline.

    Overall, it seems to be a solid light. I got it for under $20 (kit w/battery, charger, etc). The seller on Amazon no longer has any in stock. It seems most other sellers are listing it MUCH higher (~$70-80). I not sure if it's worth that much. It's a steal at $20, but a bit simple (under-engineered) for ~$80.

    edit: I forgot to mention the UI. Starting from the off position one press ->High->low->strobe(hi). There seems to be a hidden stepless mode. If you hold the button down (start from any mode), the light will start to ramp up/down until it hits the top/bottom level and then ramp back down/up. It will cycle up/down continuously until you let go of the button. The light will maintain that intensity. Another button press will then advance to the next mode (if started in off, goes to hi. if started in low, goes to strobe, etc).

    I'll try to answer any questions you guys might have. Keep in mind, this is only my second light. I'm a bit new to this arena. I actually ordered this light, THEN started to look for reviews on it. Remember, I thought I was getting that 7xLED circular light. It was then that I found this forum and started to read about the more neutral white LEDs. I've since ordered a BT40s kit on the group buy and a BT21 light off ebay. Can't wait for those to arrive!

    I'll update later with beam pattern if I can get a proper setup. Is there a certain protocol for this? I've only got my camera phone.

    edit: dunno why some pics are showing, but others are just links?
  • 05-24-2015
    Interesting looking light lol. Could be great not sure what the power is like from it though.

    as for pics, go with and it will show them all fine.

    As for beam shots, I use my phone no problem, but you have to be able to adjust your camera setting which may require an app (and phone having a decent camera). Use white balance as daylight, ISO 400 and exposure 1/10 to 1/6. I always have to try a couple times with exposure to get it so picture matches what im seeing.

    Ass for your mounting, there isnt a "right and wrong" its whatever works for you.

    But from what your saying sounds interesting, maybe a bit under driven (but case may not be able to hold much else being the shear number of emitters) and very simplistic (yet thankfully no coil). Cant begin to speculate on how its set up from the pics though.
  • 05-24-2015
    For ~20$ it wouldn't be fair to complain, you can't get one XM-L2 emitter (on a aluminium board) for less than 3$ so just emitters alone are worth more then what you paid, but from usability stand of point this light is absurd.
    Driver is a joke but if you are up for it you will probably be able to increase current flow to emitters by replacing R8 and R9 resistors with lower value versions, just for kicks, but although it is easily doable I would not recommend it because this light doesnt have enough thermal mass for running 3 x XM-L2 emitters (at decent power, 20W+) let alone 8 of them.
    Not to mention a battery pack, for 8 emitters you would have to use at least 8 good cells, I presume yours have 4 cells or at best 6 of them but if you were to power 80W light (like this one is supposed to be) battery pack would probably explode in a matter of seconds and create a black hole that would suck everything until whole earth would not be consumed by it. :D
    If truly designed as 80W light it would suck at least 24 Amps from cells, that battery pack will not last long for sure.

    Don't really see connections among emitters on their MCPCB but I would say they are in 2A4P configuration so the driver would be just a pass thru DD with added PWM...

    On a flood and throw:
    To get more throw you need larger/wider reflector with single emitter inside and only way you could stuff 8 emitters in a small housing is to jam them close one another and make very small reflectors, smaller the reflector is less focusing power it has, light is spilled all over the place.

    But for under 20$ it's a nice score for experimenting ;)
  • 05-26-2015
    Dusty Trails