I have a conflict between my headlight (cygolite metro 300) and my computer (cateye strada wireless). Mounted on the handle bars, the light kills the computer. It has to be moved away from it in order to work. I have moved the computer to the front of the top tube and it works fine. I like it much better on the handle bars because I don't have to look so far down. I guess it's not that big a deal, but it does add an element that I enjoy.

Lbs said they had never seen it happen before. They gave me another computer trying to "fix" what was wrong with the computer that kept dying.

Would just as soon not add one of the accessory bars if I don't have to. Anyone dealt with this before? Is there some way to shield the computer from the light, without adding something that looks ridiculous?

personally, i run "wired" computers.

they're cheaper and more reliable, no?

why run the "wireless" except that it's the "newest" technology?

Nothing inherently wrong with wireless computors. I got one as a gift, that is why I run have one on my bike. I have experienced interference issues with my wireless computer also. So, I reinstalled my original wired one and now I have more data than I will ever know what to do with.

If you ask this question in the electronics area, might get better feedback.

This was a gift also. Lesser powered lights did not cause the issue. Have to think on it a bit.

Well, as an electronics tech, I can tell you that there is nothing wrong with wireless technology and all its convenience but the high powered LED lighting creates enough harmonics and electronic noise to affect the computer. In this case, the wired unit would fair better. Leave your computer mounted in the handiest spot and move the light instead until you can rectify the issue.

Actually it is very common problem. It is just that most people do not ride at night so the LBS are not always aware of the issue. Sadly most wireless computers are affected by LED lights. LED lights produce Electromagnetic Interference or EMI as it is more commonly referred to. Other style of lights do not. It is not the LEDs but design of the circuit that runs the light that causes so much EMI.

I had this problem with my planet bike front light and a bontrager computer. Interestingly when I got a cygolite 420 there was no problem and I could move them closer. My guess is there's a bit of luck whether a light leaks the right kind of interference in the right spot. I don't know if it helps you, but my problem was only when blinking. Solid lights didn't cause a problem.

Before I upgraded I experimented till I found a spot where they were just far enough a part they would both work. It wasn't ideal position, but at least they worked.

That is exactly the way mine behaves. I use a blinky light on my helmet, so staying with the handlebar mount for the puter and leaving the headlight on steady is an option. I will look for something to act as a shield. Maybe a small piece of heat tape with the alm. foil on one side. If it could be a small piece, positioned in just the right place, maybe it would do the trick. Thanks for the replies.

Paradoxical are we today?

Also, not all LED lights produce the same EMI. Some have much better shielding than others, though that adds weight and cost.

On my cygolite I use the pulse mode where the light doesn't go all the way off but pulses brighter instead of the full blink and I don't get interference. Have you tried running that way?

I had a similar problem, where my wireless Cateye bike computer would show me going >100mph whenever I turned on my headlight.

My solution was to upgrade my bike computer to a garmin edge

I think I would just get a video camera, to document for all my friends................................... that 100 MPH should be good for a very long time.....

Yep, either of the flash/pluse modes knocks it out. Any of the steady modes are ok.

+1 I have two different wired cateye mity 3 computers that are almost 10 yrs old. They have never needed a battery and are still going strong. How many electronic devices can you say that about?

Easy fix:

Mount the computer where you want it.

Mount the headlight upside down, so that it is actually below the handlebars. Usually a better spot for the light anyway because it doesn't stick up above the bars so much.

Worth a try.

I strap a small softside cooler (lunchbox) to the handlebars. It would block the light completely.

If you wish to get crafty, you can probably put together some kind of EM shield using aluminum foil or another metal. It should connect electrically to some part of the bike (as a ground - I know, it's not a ground, it will probably function well enough, assuming you aren't running carbon). if you have a particular light and computer arrangement you like that will stay fixed, you could probably make a shield that was fairly small, but you'd have to play around a bit to see where it needs to be. I do not recommend simply wrapping the light in foil. While probably effective electrically, it may cause heat problems with the light.