Bike computer / light interference


New Member
I recently got a cheap Maplins wireless bike computer, and I thought it was pretty neat for the money. However, just recently I've been having some trouble with it - it sometimes measures my speed as being much faster than it actually is.

Today I worked out the what the problem is.

My bike computer is sat right next to a Cateye 3 LED front light on my bars, and when I have the Cateye turned on (I tend to have it turned on to blink mode), I get an extra 32Mph added to my speed, even when I'm stationary.

I'm not sure what frequency the wireless sensor on my computer uses, but it's quite evident that when in use my Cateye produces pulses at a similar frequency. I guess I'll have to move my computer over to the other side of my bars now! ;)


Senior Member
Birmingham, UK
I've heard of similar things with HID lights too. Does the interference still occur when on steady mode?

Elmer Fudd

Miserable Old Bar Steward
Had the same problem with my computer, I was doing 27mph when stationary, and I also had intermittent problems when the light was on constant. I'd go wired every time if you are using l.e.d. lights.
I have the same problem with my SMART Polaris LED's sometimes interfering with the Raleigh Wireless computer. I think it only does it when the LED batteries are nearly dead and my other lights (LED's also) don't. My computer tends to underestimate when it goes awry, i.e when I'm flying downhill it only reads 0 or 1mph.
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