light for winter endurance racing- Mtbr.com
Results 1 to 21 of 21
  1. #1
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    175

    light for winter endurance racing

    I am looking to build a new light for a snow races coming up.
    The main focus is on long battery life and not so much on max lumens.

    In he snow you need very little light anyway, and on a loaded fatbike your are not very fast either.

    was thinking of using a bflex. not sure about the 1 or 3 leds.

    What leds provide a decent amount of lumens at a lower power level ?

  2. #2
    mtbr member
    Reputation:
    Join Date
    Mar 2011
    Posts
    70

    light for winter endurance racing

    I recall that somewhere here at mtbr there is an illustrated and interesting discussion by a Russian member of the most appropriate colour temperatures for LED lights for use in the snow. It may have been started by the fellow behind the Easy2LED site (see here). It's worth trying a search if you haven't already done so. I recall that it was felt that neutral or warmer colour temperatures provided better contrast and detailed vision. No snow where I live (unfortunately...)

    Savvas.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Mar 2011
    Posts
    70
    These threads may be useful for LED selection (address colour temp more than efficiency etc)...

    http://www.candlepowerforums.com/vb/...t-in-the-rain!

    http://forums.mtbr.com/lights-night-...ng-785180.html

    Savvas.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    175
    thanks Savvas, no snow here either but ther is in Lapland, Finland :-)

    had not thought about the colour, interesting point. (although my chinese el cheapo was good enough last year)
    however, i am looking for something more "fuel efficient".

    most threads here are about max lumens, but i am more interested in less lumen, but more burntime. any input will be appreciated!

  5. #5
    jl
    jl is offline
    climb
    Reputation: jl's Avatar
    Join Date
    Feb 2004
    Posts
    2,293
    How about this?
    Attached Thumbnails Attached Thumbnails light for winter endurance racing-img_2554.jpg  

    We don't need more to be thankful for; we just need to be more thankful.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    175
    please explain what you have build.

  7. #7
    jl
    jl is offline
    climb
    Reputation: jl's Avatar
    Join Date
    Feb 2004
    Posts
    2,293
    Quote Originally Posted by constantijn13 View Post
    please explain what you have build.
    Below is the list of items used in the build. I first drilled 2 holes in the copper tube cap, and ran the wires from the LED through the cap. Also I drilled a hole in the side of the reducer for the power cord. The power cord is inserted through the side of the reducder and is connected to the push button switch. I then soldered the leads from the driver to the LED. I attached the LED inside of the copper tube cap, and used this as a heat sink. I used some 'silver adhesive' to adhere the LED to the cap. I also cut the reducer to be the same length as the tube cap. Then inserted the copper tube cap into the copper tube reducer with a small copper sheet shim between the cap and the reducer. I placed a small amount of solder to bind it all together.

    In the back of the reducer I soldered the power cable to the switch and connected it to the driver. I then inserted all of this into the back of the reducer and used some electrical table and a couple of silicone stand-offs to secure it in the back of the reducer. I enclosed the back of the lamp with a copper washer 'glued' to the back of the reducer with some JB-Weld. The switch is exposed through the center of the washer and is secured to the washer with some JB-Weld. Need to make sure that the wires don't ground out to the copper from the switch. I had to cut the switch leads down to fit in the reducer.

    I put the lens into the front of the cap and then secured it with some clear silicone. This is a very 'light' light and I'm using it as a helmet light. It has 3 levels low, medium, and high. The low is too, low, the medium works great and I ride at that level most of the time. The high works great, but I the driver is 2800mA and runs everything pretty hot, but I haven't had any problems.

    One thing I forgot to do was put a zip-tie strain relief on the inside of the cap reducer. It hasn't been a problem, but I fear that the wires may pull off of the driver over time. There is a small rubber washer being used around the wired and the inserted in the copper reducer to help with the strain relief and water resistance.

    So far this has been a great DIY light. Unfortunately, I don't have any pictures of the build process. Also you need to make sure all the power is connected properly from the battery to the driver using the cctv cable.

    Driver: 8* AMC7135 4-Group 2~5 Modes LED Flashlight Driver Circuit
    LED: Cree XM-L T5-5C1/4000K Neutral White LED Emitter with 16mm Base
    Lens: 20mm 15-Degree Optical Lens/Optic for Cree XM-L LED Emitters
    Push Button: OMTEN 1217 1.5A 250V Pushbutton On/Off Switches (2-Pack)
    Battery Pack: 1S4P 18650 3.7V Holder Case Battery Li-Ion PCM Protection Circuit Module
    Power Cord: 5.5*2.1mm M-F Power Cable for CCTV Security System Camera

    From Ace Hardware
    Copper Tube Cap
    Copper Tube Reducer
    Copper Washer

    From Michael's Hobbies
    Copper Sheet for a Shim

    This is a similar build but using a different driver, LED, and power supply.

    Improved high power LED bike head light with integrated heat sink

    Final note this is a 4.2v set up with 4-pack battery. I don't know how much time it can run, but it has to be a lot. More than 3 hours that's for sure.
    Last edited by jl; 01-07-2016 at 09:17 AM.
    We don't need more to be thankful for; we just need to be more thankful.

  8. #8
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,489
    maximum light for lowest power consuption thats easy to work with is xhp50 it seems now. 1.5A drive current and get over 1k lumens on a single emitter with 6v set up. Can be driven to 3A giving over 2k lumens. set to 12V you get similar lumens for less current, max 1.5A.

    Maximizing run time is easy from there, biggest issue is keeping the current draw low accross the cells so they are less affected by the cold. Say you want to run a 8.4v pack, panasonic 18650 cells (3400-3500mah) give you over 10k mah. Should get 8 hrs (more on a warm day obviously). Your run time issue is the cold reducing the capabilities of the cells. so keep the current draw low, so have parallel sets in the pack as the current draw is divided across every parallel connected bank of cells. so 6 cell 8.4v pack (2s3p) the load would be ~500mA per pair of cells iirc.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    175
    What would be the sugested optic for a xhp 50 for a 20 mm or 35 housing? (Single led)

  10. #10
    mtbr member
    Reputation:
    Join Date
    Mar 2011
    Posts
    70
    I think that you would just need to consider one of the more recently developed high-efficiency LEDs (XP-L etc) and run it at 350ma or whatever its optimal current is. You could deduce this from performance curves. As others have suggested you'd also need to run as large a battery as you can carry with cells in parallel capable of delivering this current. I understand that some LEDs suit various lenses/reflectors better than others (flood, spot etc) but this is beyond my very limited expertise I'm afraid as my favourite DIY LED is still the XR-E! Elementary advice I know but I think that your question is a relatively straightforward one. There have been a couple of recent threads about the new high intensity/high efficiency XP-L LED - might be worth reading through them. Especially the one which Scar has contributed to as I know that he has considerable expertise in choosing beam shapes suitable for use in snow...

    Savvas.

  11. #11
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,489
    Actually xhp50 is alot more efficient now. Xp-g2, optimal current at 6v is ~1500mA, over 1000 lumens @ 85C.

    And the rating for xp-l is ALOT higher than that. You quoted xp-g2 optimal current. XP-L your right is most efficient, optimal is 1050mA.

    Running a 350mA optimal emitter at that current he might as well use a cheap flashlight. An single xp-g2 at that current isnt much better.

    As for the question of optics: 26mm minimal optic diameter, bigger is better on xhp50 unless your going really floody beam. Any tight optic on it you will get a tight spot, but you'll also get 4 squares around it.

  12. #12
    arc
    arc is online now
    mtbr member
    Reputation:
    Join Date
    Sep 2004
    Posts
    359
    How do you get rid of the 4 squares?

    Dual emitter, orange peel reflector?

  13. #13
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,489
    Neither. DONT USE REFLECTORS! Wide spot that's textured or large diameter TIR optic. A regular smooth reflector you'll end up with a dark hole where the spot should be, orange peel is alot better but squares are there (I dont use reflectors, a buddy that's a flashaholic filled me in, I have a test light for a company that uses one on tir optic). Wide spot textured TIR optic, large diameter TIR optic, or multiple emitters are really the only way not to get the squares or "donut hole".

  14. #14
    mtbr member
    Reputation:
    Join Date
    May 2005
    Posts
    3,817
    The Fraen narrow reflector for the MCE emitter, which is also a 4 die design, made a really nice beam despite the large die size of the MCE. It's been a long time since I used my dual MCE light, but don't recall it projecting the dies nor having a dark center. The XHP has a similar die size to the MCE so I would expect a pretty decent beam using the Fraens. It is a 35mm reflector so small designs are out of the question. Ledil Iris is a large die TIR optic that also made a pretty good beam with the MCE. It too is a 35mm (maybe 36mm) size. TIR optics in those sizes are chunky pieces of plastic so no ultralight builds are happening with them.
    GoPro adapters for bike lights http://www.pacifier.com/~kevinb/index.html

  15. #15
    arc
    arc is online now
    mtbr member
    Reputation:
    Join Date
    Sep 2004
    Posts
    359
    When I saw higher efficiency I immediately thought smaller battery + smaller heatsink = lighter helmet light, heavy reflector with a big housing kills that idea.

    I now know why no one else is using them.

  16. #16
    Laramie, Wyoming
    Reputation: alphazz's Avatar
    Join Date
    Oct 2012
    Posts
    1,941
    If you are talking winter endurance races, how extreme are you talking? What temps and how much run time is needed? Why aren't you thinking about a dyno hub? It's the only way to not have to worry about batteries and how long they will last.

  17. #17
    Yeah!
    Reputation: Flamingtaco's Avatar
    Join Date
    Mar 2012
    Posts
    1,457
    Quote Originally Posted by constantijn13 View Post
    thanks Savvas, no snow here either but ther is in Lapland, Finland :-)

    had not thought about the colour, interesting point. (although my chinese el cheapo was good enough last year)
    however, i am looking for something more "fuel efficient".
    The good CRI of warmer bulb isn't critical unless you want to pick out snowshoe hares, but as endurance races are also a mental battle, using an LED that provides a CRI closer to a full noon sun will help with your mental battle. The bulk of white LED's are 6000k, which is close to the light of an overcast day. Not horrible lighting, but after riding a few years with them, being passed on occasion by cars with 4500K headlamps, I'm looking forward to swapping out the 6000's for warmer LED's.
    I will suffer no butt-hurt fools!

  18. #18
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    175
    Quote Originally Posted by alphazz View Post
    If you are talking winter endurance races, how extreme are you talking? What temps and how much run time is needed? Why aren't you thinking about a dyno hub? It's the only way to not have to worry about batteries and how long they will last.
    300 km winter race on fatbikes. temperature can vary between -5c to -35c

    dyna hubs are optimised for say 18 to 25km per hour speed, which you not often reach on a fatbike, off road

  19. #19
    Laramie, Wyoming
    Reputation: alphazz's Avatar
    Join Date
    Oct 2012
    Posts
    1,941
    A dyno hub is exactly what a few of us will be using at the Arrowhead 135 in a little over a week (that's about as extreme as it gets). It is more than bright enough for riding down to around 3.5 mph. It starts flickering some while walking but will still light the path at 2.5 mph. The faster you go, the brighter it gets and it can charge an extra battery during the day. It is the way to go.

  20. #20
    mtbr member
    Reputation:
    Join Date
    Mar 2011
    Posts
    70
    I guess I was reasoning that at 350ma he was most likely to get the longer run-time he was after. In my experience 350ma - even with an XR-E - will generate plenty of light. Remember he won't be going fast - just as fast as he can in snow for a long way! Anyway, I think someone will need to run the numbers...

    Savvas.

  21. #21
    mtbr member
    Reputation:
    Join Date
    May 2005
    Posts
    3,817
    Quote Originally Posted by Vancbiker View Post
    The Fraen narrow reflector for the MCE emitter, which is also a 4 die design, made a really nice beam despite the large die size of the MCE. It's been a long time since I used my dual MCE light, but don't recall it projecting the dies nor having a dark center. The XHP has a similar die size to the MCE so I would expect a pretty decent beam using the Fraens. It is a 35mm reflector so small designs are out of the question.
    Got a quick look at an XHP70 with the Fraen narrow reflector for MCE. Fits perfectly and does make a very nice beam. Particularly for a bar light. At 1A on the test rig it was nearly as bright as my 6 up (3P2S) XPG R5 light at 3.5A. Hard to compare perfectly though as the XPG is cool white and the XHP is neutral to warm white. So 12W on the XHP70 versus ~20W for the XPGs for nearly the same apparent light looks like a good combo.
    GoPro adapters for bike lights http://www.pacifier.com/~kevinb/index.html

Similar Threads

  1. XX1 for endurance racing?
    By pulser in forum Endurance XC Racing
    Replies: 51
    Last Post: 05-15-2013, 02:16 PM
  2. Some endurance mtb racing in So Cal
    By moab63 in forum California - Socal
    Replies: 1
    Last Post: 03-28-2012, 01:41 PM
  3. Anyone using KM for endurance racing?
    By El Train in forum Surly
    Replies: 4
    Last Post: 01-21-2012, 07:51 AM
  4. New to endurance racing...
    By Zach75 in forum Endurance XC Racing
    Replies: 10
    Last Post: 11-27-2011, 05:51 PM
  5. Endurance Racing and Enduro Racing??
    By bodben in forum Beginner's Corner
    Replies: 4
    Last Post: 02-18-2011, 05:08 PM

Members who have read this thread: 0

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2020 VerticalScope Inc. All rights reserved.