Commuting - Headlamp vs bike computer

Recently my bike computer has been on the fritz. I thought that it was time to have it replaced but on an early ride home the other day it was working just fine. The only difference was that I had not reattached my head lamp and its battery b/c it was still light out! Has this happened to anyone else before?
The headlamp is a Mini Newt and the battery is attached under my stem. Unfortunately, the wire from the battery to the lamp is pretty short and it won't reach to my down tube. I've got a frame pump on my top tube and prevents the battery from being placed there. The computer is a wireless trek model; nothing fancy, it cost maybe $40. Any suggestions to have this resolved would be appreciated.
Should I buy a wired computer?

put the battery on the stem?

unless your computer has a back light, it's not useful at night.

Do some more experiments. Unfasten the light and battery, and move them around to see if one unit or both affect the computer. While Niterider does sell an (expensive) extension cable, if it's not just the battery pack, you may need to get a wired computer.

I can guess that the regulation and dimming circuit could put out radio interference. Another reason to like wires, perhaps.

Yeah, many LED and HID lights interfere with wireless computers and HRMs. For LED lights, it usually happens only when using reduced-power modes, since the light switches to pulse-width modulation to lower the output (basically, it strobes the light at such a high rate that you can't tell it's not running solid).

So one option is to try running your light at full power, if you weren't already. Another is to move the stuff farther away from eachother. With a MiNewt, one possibility is to get a bigger, stronger O-ring and mount the light around your bike's head tube. Some people won't like the fact that the light now steers with the frame, instead of the bars, but you can always give it a try. O-rings don't cost much :)

Getting a wired computer will also fix the problem, yeah.

I had this happen with a NiteRider Sol. Turned out the battery in the transmitter for my cyclocomputer was also weak. Once I replaced the battery there it was fine.

NiteRider makes a longer cord separately. Might be a good option.

Also, you may want to look into the NiteRider computers. They run on a different frequency than their lights so you can use both wirelessly. Start around $100 or so... more expensive option but they're pretty damn nice computers.

The timing of this is funny. I just got an answer to the exact same concern from NiteRider not even two days ago. In short they recommended experimenting with the battery placement. I didn't bother replying that the idea was bordering idiotic - the MiNewt's cord length prohibits much in the way of "experimenting".

One point to mention is that I have no issue at all at high/low power as long as the battery is reasonably charged. As soon as the red light comes on (down to 15% charge remaining) - poof! My Cateye Strada wireless freaks out. This is probably the phenomenon that mechBgon is explaining(?)

It's easy enough for me to plug the battery in to charge after each use now that I know what the issue is.

Yeah, many LED and HID lights interfere with wireless computers and HRMs. For LED lights, it usually happens only when using reduced-power modes, since the light switches to pulse-width modulation to lower the output (basically, it strobes the light at such a high rate that you can't tell it's not running solid).

So one option is to try running your light at full power, if you weren't already. Another is to move the stuff farther away from eachother. With a MiNewt, one possibility is to get a bigger, stronger O-ring and mount the light around your bike's head tube. Some people won't like the fact that the light now steers with the frame, instead of the bars, but you can always give it a try. O-rings don't cost much :)

Getting a wired computer will also fix the problem, yeah.

+1 This is the answer. I had the exact same problem with a MiNewt/wireless computer setup. The annoying thing was that I was convinced it was my HRM at first, so it took a while to diagnose. My solution was to run the light on full power, all the time (never low or strobe). That solved the problem. Maybe a longer cord would help, but I got the impression it was the light itself, not the battery that was causing the problem (didn't test that, though). Anyway, if you're not willing to give up low power and strobe, you need to either dump the computer or get a wired model. I suppose helmet-mounting the light would be an option as well... I know NiteRider makes one for the MiNewt.

Good luck.

unless your computer has a back light, it's not useful at night.

It can still be useful. I like keeping track of the total miles, or taking the computer inside to look at the totals from that trip.

I had the same issue with my MiNewt X2 and Catseye wireless computer. Moving the battery to the left side of the stem (computer is on the right) and only using the "bright" setting on the light fixed it for me.

Thanks for all the posts. I usually ride with the light on strobe and that's when I notice the interference. At night when the light is on full power I can't see the mph and don't know if it is being affected or not. I'll try just riding on full power this evening on my way to work.

Maybe this is overlooking something because my idea seems too simple and cheap. You can't change battery location because the cord to the light is too short. Do you have the mechanical skills to simply securely splice some extra cord into the battery/light cable so you now have enough length to move the battery out of harm's way of the computer?

It can still be useful. I like keeping track of the total miles, or taking the computer inside to look at the totals from that trip.

Me too, and my helmet light eliminates the need for a backlight, too.

I put my garmin 705 in my pocket at night. Works fine from there.

It's very common for wireless computers to get bothered by lights. Personally I can't imagine why I'd want to use a wireless computer. Installation takes about an extra 2 minutes, then I don't have TWO things with batteries to bother with.

I don't use wireless internet at home either, unless there's no choice. Wired just always works. Wireless is a crapshoot.

unless your computer has a back light, it's not useful at night.

It's every bit as useful when I can't see it as when I can. I only use mine to keep track of mileage on the bike for maintenance purposes. I don't actually look at it when I'm riding, except for the time of day display sometimes.

Maybe this is overlooking something because my idea seems too simple and cheap. You can't change battery location because the cord to the light is too short. Do you have the mechanical skills to simply securely splice some extra cord into the battery/light cable so you now have enough length to move the battery out of harm's way of the computer?

You can buy NiteRider extension cables too, in varying lengths. The connectors are fairly specialized so this is probably a much easier option.

http://www.jensonusa.com/store/sub/199-Lights+And+Reflectors.aspx?s=1109