Chris!

I got a night rider head light from REI recently. So I mowed the lawn and thought I'd enjoy an evening ride watch the sun go down and ride home. Turn my new 1000 lumin head light on and my wireless speedometer stopped working. What up with that?

CycleryNorth81

Your light is interfering with your speedometer. Change the speedometer to a wire one or change the light.

JanMM

Electronics not playing well together. I've never experienced that but understand it's not uncommon these days.
REI is good on returns - wonder if they would help you located a light that won't interfere?

MoAlpha

There’s lots of talk about LED navigation lights interfering with VHF radios on boats. Didn’t happen to us.

sweeks

The interference may be minimized by separating the light from the computer as far as possible (it's the old "inverse square" law). You might also try placing a piece of metal (or even aluminum foil) between the two devices. The barrier should ideally be "grounded" to metal handlebars if you have them. I'd try the separation first. :-)

General Geoff

I had the same problem with my Niterider headlights. Moving the cyclecomputer about 5" away from the light solved the problem.

Chris!

Thanks for the ideas. I'm going to try and separate them. I like the light and the speedometer. I got the 1000 lumen light on sale so I'd like to keep it. I'm not sure I'll have to check tomorrow but I wonder if my speedometer is on the same side as the sensor maybe correcting that if needed will help too.

jgwilliams

I had the same with a NiteRider 750 lumen light. In fact I complained to NiteRider about it and their response was that it was because they were driving the LED so hard. I can tell you this is tosh as I now have an Exposure Strada 1200 lumen light which you can put right next to the computer without any interference whatsoever. It's down to how well the light is shielded for RF interference. I have to admit I was disappointed by NiteRider's response as I feel that otherwise they are good lights - although they battery on mine was a bit small - and for that reason I won't be buying them again.

I found that by putting enough separation between the light and the computer I was able to get them to co-exist.

Chris!

I tried just moving the light as far over on my bars as I could and it worked. I dont do much night riding so I'm happy.

Gresp15C

I do some work with electronics for my day job. Here's my guess. The light is controlling the amount of current fed to the lamps by "chopping" the power, i.e., switching it on and off very rapidly. The electromagnetic noise emitted by this process must mimic the signal from the speed sensor in a way that confuses the speedometer.

If you swing the light back and forth while looking ahead, you might notice what looks like a trail of bright dots. My light (cheap rechargeable Xanes from banggood.com) produces dots in "dim" mode but not "bright" mode, so I think the dim mode works by just chopping the lamp on and off at a 50% duty cycle.

TimothyH

+1

Exposure Strada 1200 about an inch away from a Polar GPS.

I ride >100 miles/week in the dark and have never had a bit of trouble with this setup.




-Tim-

Sy Reene

Knight Rider headlight?

UniChris

Actually there may be some truth to their claim. If the light is pulsed, as most are, then a very fast slope to the pulse (ie, a "hard" edge) will radiate harmonic energy well into radio frequencies, the faster the edge the further up the spectrum. Mitigation would be about slowing the edge speed, not just shielding, though that might(?) reduce efficiency a tiny bit.

Which wireless sensor? Looking up its FCC I'd may indicate the radio type in use. If it's something primitive it's not hard to imagine interference.

I've thought of building a wireless computer and would probably use a digital FSK radio with some repetition in the coding.

GGreenhorn

I had the same problem, my Night Rider light would mess up my little Cateye wireless causing it not to function. I just reoriented everything so the light is as far away from the Cateye (and the light beam is as far aware from the Cateye sender - reciever path) on my handlebars as possible. My Cateye also tends to not work so well at around 32 degress. When it was dark and cold in the mornings, mileage was just an educated guess.

teejaywhy

Had a weird problem with my garage door opener. Put a LED bulb in and suddenly, the remote was not working reliably. But only when I was leaving and wanting to close the door. Coming home, the door would always open just fine. Finally figured out it was related to when the light was on. Switched out the bulb and problem solved.

dmanthree

Chamberlain recommends only certain LED bulbs for their openers. Yes, when the light is on it can interfere with the remote opener. I had the same issue and swapped to the recommended LED bulbs and problem solved.

Clearly, the same issue can affect a bike computer. I have a Nite Rider Lumina 850 that's mounted below a Wahoo Elemnt Bolt and have zero issues. No RF with that setup, though.

AndreyT

Your light is operating in PWM mode, which means that it blinks rapidly, creating radio interference.

Many lights on the market use PWM only in reduced brightness modes (this is how you reduce brightness of a LED light). When you switch them to full power, they are no longer PWM-ed and no longer interfere with other equipment.

So, were you running your light in full-power mode when you noticed the interference? If not, then try it and see what happens.

If you still see interference even in full-power mode, then you are out of luck: your light is incompatible with your wireless cycling computer. Try to keep them as far apart as possible, and if that does not help - change the light, change the computer, change something else.

jgwilliams

If the Polar is only using GPS then you wouldn't see any interference anyway. My Garmin was never bothered by the NiteRider. The Garmin also links to HRM and speed/cadence sensors which also continued to work fine because the signal was digital. It's only the analog link between the CatEye computer and speed sensor that was affected. Those Strada lights are really good, though, aren't they?

DomaneS5

Get a wired Cateye bike computer like the Velo 7 or Velo 9.

fietsbob

Put the light on your helmet, on your head ? I have an older NiteRider which doubled as a Diver's light...








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Aubergine 

I have had the same issue (and asked the same question here!). I discovered that dynamo-powered lights play nicely with computers, so I have those on my primary nighttime bikes.

Payton1221

Not to hijack but what's the traffic like where you're riding in the dark? If anybody should be able to ride in the dark, it should be me since I live in the country with car sightings typically averaging one every five minutes, but with that noted, I've never ridden in the dark.