Cateye interference

[Monsieur Remings]

Okay, just bought a new light, a Magicshine. The last two nights I've been out I've had problems with my speed fluctuating on the Cateye. Now, let me explain, I have both a Cateye Strada Wireless and Cateye Micro Wireless. To cut a long story short I swapped the monitors around and found to my delight that they both worked with each other's sensor...so far so good. Last night I had a problem with the speed fluctuating and so today I bought a new battery for the sensor and the same thing happened. I swapped the monitor's back over so each monitor was working with its original sensor and although it was better it started doing the same thing again.

Now both monitors cannot have decided to misbehave along the same lines on the same night so either there's a problem with the magnet - a Mavic, and I really can't see what, or the battery pack for the MS is screwing the signal. Read elsewhere that some HRMs also affect speed fluctuation so anybody had experience of this?

It's typically annoying as my computer is my training tool and I can't do without the light...

 

[Edge705]

Magnet - makes no difference they all work in my experience
Cordless Cat-Eyes are prone to interference I found them terribly unreliable at times and had to mount the transmitter high up on the forks (least distance to receiver)
Magic Shines use electronic circuit boards with emmiters (non bulbs) (I beleive) therefore there will be some kind of radiation pollution I suspect this may be your source of the problem but I stand corrected if anyone else can confirm otherwise Have you tried without the magic shine?

I doubt the battery pack is the source of the issue but Im no expert

 

[Monsieur Remings]

Yep, have been using it with no problems before but will check once more on Sunday when I'm out during the day. What's particularly annoying is that sometimes the speedometer stops altogether making mileage total very difficult. I'm trusting that by your username that this kind of thing wouldn't happen with a Garmin?

 

[andrew_s]

LED lights are notorious for making wireless cycle computers go haywire. All you can do mount the light and the computer as far apart as possible, or switch to a wired computer if all else fails.
I'd try getting a Minoura Spacegrip and putting one or the other on that.

It will be the Magicshine light head rather than the battery.

 

[slowmotion]

I don't want to insult your intelligence but my first port of call would be to check the magnet to pickup spacing on the spoke and fork. I have a Cateye Wireless Strada too. The display sits on top of the stem. My front light is a Hope Vision One. The rear of the light actually touches the side of the display and I have never had any problems in two and a half years use. My guess is that your light is chucking out EMI that the Cateye cannot handle. I could be wrong. Anyway, I hope you manage to sort it out.

 

[Edge705]

by your username that this kind of thing wouldn't happen with a Garmin?

Correct and its also much faster at updating your speed than the Cat Eye you dont need a speed magnet and the speed and cadence is in one nice tidy unit its more than a computer its a personal training companion with built in gps maps the downside of course is that it needs charging frequently I usually get 3 - 4 daily 28 mile commutes before it needs recharging Im told with GPS turned off and the screen on low light it will do 12+ hours

 

[slowmotion]

Sell them?

 

[mr_hippo]

Correct and its also much faster at updating your speed than the Cat Eye you dont need a speed magnet and the speed and cadence is in one nice tidy unit its more than a computer its a personal training companion with built in gps maps the downside of course is that it needs charging frequently I usually get 3 - 4 daily 28 mile commutes before it needs recharging Im told with GPS turned off and the screen on low light it will do 12+ hours

Of course, it would not happen to a Garmin!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

986.4 kms at an average speed of 348 kph in a time of 2hr 48 mins.

 

[PatrickPending]

As has been pointed out wireless systems such as cycle computers can be susceptible to electromagnetic interference (EMI -stray radio frequency noise). In this case the light - being LED is likely to be pulsed - albeit at a high frequency (so you don't notice the pulsing) on low power settings (maybe even on the highest power can't be sure). It is this high frequency switching that causes the EMI and interferes with the computer at night. Susceptibility to EMI depends both on the light and the computer itself. You could try positioning the light as far away as feasably possible from the light it may help but I can't be sure. Other sources of EMI are available (such as HRMs) though LED lights are particularly bad. One of the reasons I use a wired system on my commuting bike - given that this time of the year my commute is entirely in the dark!

 

[PatrickPending]

oh i should add the switching circuit can be in either the light itself or in the battery pack (ayups) or as a seperate switching unit (cateye double/tripleshot) - usually where the switch is is the place where you will find the led drive circuit. Not familiar with magicshine sorry.

 

[Monsieur Remings]

Thanks one and all. Slowmotion, yes was my first thought when it started on the blink and I will restrap the sensor anyway, a bit higher this time round.

Jury still out on whether to buy a Garmin! What's rather annoying is I only bought this light because of a let-down on my TML Cree (sent a dodgy charger with no UK adaptor) but I guess this could have caused the same problem anyway being an LED.

What a pain in the posterior...

 

[Scilly Suffolk]

Being as this seems to be a fairly common problem, you'd think that someone would have come up with some sort of shielding.

Anyone know what blocks EMI?

 

[PatrickPending]

you need to create a farraday cage - its a cost benefit thing plus you have to let the light out somewhere. Some wireless computers have a more sophsticated coding signal which makes them more immune. My first cordless one was set off by electric fences and traffic light induction loops!

 

[Holdsworth]

So far I have had no such trouble with my MS MJ-808 used in conjunction with a Cateye Micro Wireless. Maybe some are more susceptible than others to RF interference.

 

[HovR]

I have a front light on order which uses the same emitter as some of the Magicshines - Hopefully it won't interfere with my Cateye Vectra Wireless!