I use a powerful Dinotte headlight and have the same problem. I was able to remedy the computer problem by locating the light on the front of my front rack, thereby getting it as far from the computer as possible. May not work in your situation with your current set up. This year, I took my front rack off and couldn't get the light far enough away from the computer for it to work, so am using a less powerful light that doesn't confuse the computer.
Originally Posted by
bragi
I recently got a new, more powerful light for my bike (Nite Rider MiNewt 350), and quickly noticed that whenever the light is on, my wireless cycle computer stops recording mileage or speed. It just goes into a kind of petit mal seizure. When I turn the light off, the cycle computer "wakes up" and functions normally again. Is this a common problem with more powerful bicycle lights? It never happened when I used a $30 Cateye light. More to the point, what's a reasonable solution, other than getting a wired cycle computer? I kind of like not having many wires on the bike.