Maybe someone will have an idea to help me.

I just bought a PB Blaze 2 watt. I mounted it on the handlebar where the PB Beamer 3 used to be.

All of the sudden, my Specialized wireless cyclocomputer is going haywire. It said I traveled 77 miles at an average of 55mph.

I'm fast, but not that fast.

I tried moving the Blaze as far away as I could on my road handlebars, but there isn't much room. I even tried mounting it upside down, but it still interfered with the computer.

Any suggestions?

Here is a quick pic.

Does the Blaze have multiple power settings? I had same issue with different light + computer. However, on brightest setting computer worked OK, but on lower settings it zeroed out.

Yep. I have a Blaze and it works amazingly well on just two AAs. I'm sure it has a switching current regulator that evidently puts out enough electrical noise to interfere with your computer. You might try swapping things around on your bars to separate the computer and Blaze as far as possible keeping the computer closest to the wheel sensor.

The Blaze has low, high and superflash settings.

It affects the computer in all settings. None of the other lights I used had any affect on the computer.

The computer is setup on the stem, so moving it really isn't an option. There isn't much room on the handlebar either.

Have you tried putting some kind of shield around the Blaze? Maybe aluminum foil . . . ?

I tried all that stuff...with my Magicshine lights, to no avail. My 1W PB headlight never gave me problems, but the two Magicshines sure have. Since you do picture a Magicshine headlamp in your cockpit, are you sure that's not the culprit? It puts out a lot more current and wattage than your Blaze headlight, plus it has that long wire that acts like a radio transmitter.

It may be that the problem occurs not with one light on, but with both. In that case, try wrapping the Magicshine wire around the handlebar, starting from below the bar, outboard from the lamp, three tight winds before hooking to the battery. The coil effect mitigates RF interference and allows me to run two Magicshines on the handlebars at full power-about 16 watts.

It isn't the Magicshine.
I tried moving the Blaze farther away from the computer, so I had only it on. While the bike was in the rack, I was going 38 miles/hour.
I've had 3-4 different light combinations, all including the Magicshine, but only the Blaze is interfering with the computer.

I haven't tried the foil. I'm not sure how often I'd have to mess with it to keep it on.

For now I just turned the computer off and I'm using the Endomondo Sports tracker app to track my miles.

Just for reference, I have a Cateye Strada wireless computer and a NiteRider MiNewt mini 150 USB light and they don't interfere with each other. Maybe we need to start a light/computer compatibility database.

I have a Cateye Strata wireless computer and every light I have causes it to stop working.
It also picks up traffic signals and gives me a top speed of 78 mph when I am stopped at a Red light.

Any one-setting light will work fine with any and all computers. The reason that your computers are thinking you're going that fast is probably because the detector is detecting oscillating magnetic fields caused by an alternating current in your electronics. Computers that use stronger magnets will be less likely to be affected, as the sensor would likely be calibrated to a higher magnetic field strength.

What may be happening, as it happens to me, is the ground loops are throwing the computer off. My work installed car-sensing ground loops, which detect the metal of the car in order to activate the bollards and gates. When I ride over them, if I lean the bike over to activate the loop, the computer reads that I am going 99.9mph.

Several red light systems use the ground loops also.

Is there any way to tell if the computer you are about to buy is calibrated to the higher magnetic field strength?

Have you determine if the light was affecting the computer itself or if perhaps the sensor is picking up the noise and transmitting the extra info to the computer? If it is the sensor, try moving the sensor lower on the forks or move either it or the light to the opposite side.

Just tried some experiments.
Its the computer, not the sensor.
Foil works, but only if I cover the entire body from the aluminum to the back.
Making a foil shield around the computer doesn't work.
The light has to be more than 5 inches away to stop the interference. My bar tape prevents me from doing that on the handlebar.

If it's interfering directly with the computer, then I doubt the sensitivity of the sensor will matter much. You could mount the light on your fork. If you can take your light apart, you could try encasing the components in foil.

I had the same problem with my PB 2 watt and Cat eye Strata, I ended up swapping to a Bontager Node 1 that uses ant+ technology and that fixed it

Is the Node 1 wireless?

yes it is

Thanks for sharing this. I recently installed the Planet Bike Blaze 2-watt light, and it interfered with the Bontrager 5W analog wireless computer I had installed on my bike. Based on your experience, I changed to a Bontrager Node 1 digital wireless computer, and that fixed the problem. My local bike shop did a really nice thing for me: They gave me a 20% discount on the Node 1 computer. I originally bought the 5W computer from them, and although I bought and installed the interfering light myself months later, they made this nice gesture.