Cool and Clear; Bright Lights

January 30th, 2012

Although there were flurries when I woke up this morning, it was dry and clear when I actually left for work. A little wind and 37 degrees.

Clothing: Heavy winter coat, light biking gloves, waterproof shoes.

On my mountain bike, I carry a very bright light in case I get caught on the trail in the dark. While that didn’t happen this weekend, I did end up riding that bike home after dark, so I used it (in flashing mode) on the road. Wow, what a difference bright lights make. Normally, cars are aware of you with a bike light; with a super bright and flashing light, some actually get out of the way. On College Ave in Davis Square, I actually had a car move toward the center of the lane so I could get by more easily.

I can’t wait do get my home-made dynamo light out there: it is rated at 4 times the intensity of the “bright” mode from my mountain bike.

10 Responses to “Cool and Clear; Bright Lights”

  1. hughkelley Says:

    Can you fill in a few details on your “home-made dynamo light”? What is your starting point for this?

  2. Weather Guy Says:

    I’m still working on it, but the basic design is all over the internet, for example

    Also, check out

    I have a Shimano Alfine hub for the power source.

    I got all my parts from, including the housing. (I got a 3x Cree light with 417 lumens.)

    My general idea is to take their ALK housing and mount it onto a bracket on the frame. All the driver circuitry will fit inside the housing, so I’ll just run a wire from there down to the hub. Back light to be powered in series. I may add another hole to make a standlight stick out of the top – I haven’t sorted through that yet.

  3. Weather Guy Says:

    Also, if you control the voltage and power you can retrofit any old battery LED light you have to run off the dynamo.

  4. hughkelley Says:

    I’ll be interested to see more details about voltage regulation. Is that a DIY component you’ve built before?

    I cheated and just bought a Lumotec LYT.

  5. Weather Guy Says:

    I’m going off my rusty experience with circuits and a healthy dose of taking things straight off the internet.

    My impression is that I can use one or both of a zener diode to control the voltage and a negative feedback op amp to control the output voltage. What I’d really like is to make a test rig so I can spin the wheel using a DC motor.

    Also, I bought a Buckpuck, which is designed to give a constant current (I got the 350 mA version) at varying voltage, designed for LEDs. I didn’t like its performance at low speed in my unscientific tests, however.

    I hadn’t looked up the lumotec ones before (I was obsessed with the really bright lights), I may get one now as a stopgap.

  6. cycler Says:

    I LOVE my Edeluxe, which I believe is built on the same lens as the Lumotec IQ cyco , but with nicer exterior fit and finish. On my less used roadster I have the plain old IQ cyco. It has a very nice beam pattern, which I believe is often the problem with DIY lights.
    I have a 2 watt planet bike front light, but it’s not nearly as good for seeing where I’m going as the Edeluxe.

    it’s expensive, but when you compare it to tanks of gas, we’re talking 4-5 tanks..

    Its not nearly as bright as some of the ‘magic shine” type ridiculously bright lights, but I did have someone in a car tell me that he thought I was a motorcycle when I was coming up behind him.

  7. Weather Guy Says:

    I am somewhat concerned about the beam pattern, but then again, it’s so darn bright I hope it’ll make up for it. Perhaps I’ll learn how to make a lens, next…

  8. cycler Says:

    Was changing out a lightbulb in my office, and had an idea to pass on-
    I think it might be possible with a Dremel, luck and patience to cut out the “filiment” part of a parabolic halogen light like a MR -16, and use the parabolic portion of the fixture as a lens.

  9. Weather Out There » Blog Archive » Monthly Recap: January 2012 Says:

    […] your pants neat and clean (and intact), singing praisesĀ  to fenders, building or purchasing dynamo lighting, and maintaining tire pressure. Posted by Weather Guy Filed in Monthly Recap No Comments […]

  10. Weather Out There » Blog Archive » Bright Lights Mean Safety; Cool and Dry Says:

    […] 22nd, 2012 TweetI hate to repeat myself, but bright lights are for safety. With a few days of riding on my new dynamo light, I now have another anecdote to […]

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