Cateye Mity2 registering erroneous max speeds

Haluk Okur said:

My computer (Cateye Mity2) started registering erroneous max speeds lately. Last night it was
showing 98 km/h and all I did was a moderate speed ride thru the park. I readjusted the sensor and
the magnet, I cleaned the contacts to no avail.

Do you carry it off-bike while stopped, perhaps in a pocket with keys? My Mity 3, when carried in a
pocket which also contains keys, has its contacts flipped by the key, and can get some very high
cadences on there for half a second.

Jasper

Haluk Okur said:

My computer (Cateye Mity2) started registering erroneous max speeds lately. Last night it was
showing 98 km/h and all I did was a moderate speed ride thru the park. I readjusted the sensor and
the magnet, I cleaned the contacts to no avail.

Anyone seen this before? I don't know where to start to check.

Although you have readjusted, the sensor may still be too close to the magent. Try moving it further
out (if it'll still pick up). If too close, the sensor can click twice per wheel revolution
sometimes.

Quoted message said:

Battery is about two years old. Although there's no sign of low battery, can it be the cause of
the problem?

Battery is bound to be ok if display segments are dark and not light grey.

~PB

"Jasper Janssen" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Haluk Okur said:

My computer (Cateye Mity2) started registering erroneous max speeds lately. Last night it was
showing 98 km/h and all I did was a moderate speed ride thru the park. I readjusted the sensor
and the magnet, I cleaned the contacts to no avail.

Do you carry it off-bike while stopped, perhaps in a pocket with keys? My Mity 3, when carried in
a pocket which also contains keys, has its contacts flipped by the key, and can get some very high
cadences on there for half a second.

Good point, but I do it very rarely, and I pay attention not to keep metallic things like keys,
coins etc in the same pocket.

---
Haluk Okur - Istanbul Turkey

"Pete Biggs" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Haluk Okur said:

My computer (Cateye Mity2) started registering erroneous max speeds lately. Last night it was
showing 98 km/h and all I did was a moderate speed ride thru the park. I readjusted the sensor
and the magnet, I cleaned the contacts to no avail.

Anyone seen this before? I don't know where to start to check.

Although you have readjusted, the sensor may still be too close to the magent. Try moving it
further out (if it'll still pick up). If too close, the sensor can click twice per wheel
revolution sometimes.

Quoted message said:

Battery is about two years old. Although there's no sign of low battery, can it be the cause of
the problem?

Battery is bound to be ok if display segments are dark and not light grey.

Thanks for the suggestion, I actually brought the sensor closer to the magnet thinking it was way
too far (almost 5-6mm). Now there's about 2mm distance. I also adjusted the sensor vertically, so
that the magnet passes right across the center of the sensor.

Nothing changed.

I suspect the reed relay in the sensor may be damaged and vibrates on rough ground producing
additional pulses that confuse the computer.

I'll try to replace the battery. We'll see if that cures the problem.

---
Haluk Okur - Istanbul Turkey

Hi, I've seen a friend's computer (unsure of brand) register some very high speeds (and distances)
while parked. My theory is that it stopped with the magnet at or near the sensor and just continued
to click it somehow but I haven't ever tried to prove this. Lyle "Haluk Okur"
<[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

My computer (Cateye Mity2) started registering erroneous max speeds lately. Last night it was
showing 98 km/h and all I did was a moderate speed ride thru the park. I readjusted the sensor and
the magnet, I cleaned the contacts to no avail.

Anyone seen this before? I don't know where to start to check.

Battery is about two years old. Although there's no sign of low battery, can it be the cause of
the problem?

Other then this, the device functions properly.

TIA
---
Haluk Okur - Istanbul Turkey

Haluk Okur said:

I actually brought the sensor closer to the magnet thinking it was way too far (almost 5-6mm). Now
there's about 2mm distance.

I bet that's the problem. I had a similar experience with a Mity 3.

Quoted message said:

I suspect the reed relay in the sensor may be damaged and vibrates on rough ground producing
additional pulses that confuse the computer.

Possible, I suppose, but very unlikely. Every problem I've ever had with a cycle computer has been
solved by magent/sensor repositioning or fixing cable or contacts. The reed switches themselves seem
to be simple and hardy devices which have even worked with different computers when I've eventually
given up on everything else!

~PB

"Haluk Okur" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Thanks for the suggestion, I actually brought the sensor closer to the magnet thinking it was way
too far (almost 5-6mm). Now there's about 2mm distance. I also adjusted the sensor vertically, so
that the magnet passes right across the center of the sensor.

Nothing changed.

As the switch is prone to flux reversals if the magnet passes through the middle, which results in
extra 'ticks' in the signal, that could be the problem. Try moving the magnet so it passes one end
of the sensor or the other, not in the middle.

Quoted message said:

I suspect the reed relay in the sensor may be damaged and vibrates on rough ground producing
additional pulses that confuse the computer.

You'd probably get no reading at all if that were the case.

Quoted message said:

I'll try to replace the battery. We'll see if that cures the problem.

---
Haluk Okur - Istanbul Turkey

"Haluk Okur" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

My computer (Cateye Mity2) started registering erroneous max speeds lately. Last night it was
showing 98 km/h and all I did was a moderate speed ride thru the park. I readjusted the sensor and
the magnet, I cleaned the contacts to no avail.

Anyone seen this before? I don't know where to start to check.

Battery is about two years old. Although there's no sign of low battery, can it be the cause of
the problem?

Other then this, the device functions properly.

TIA
---
Haluk Okur - Istanbul Turkey

Last night I found the reason. It's hard to believe but the erratic behaviour of the computer is
caused by my squealing front brakes. I noticed it after a hard braking and lots of noise (an idiot
stepped right in front of me). I reset the computer and tried again and again. Everytime, as soon as
the squealing started, the speed display went berserk, so did the max speed.

The contact blades of the reed relay are apparently resonating with the vibrations of the fork and
creating bursts, not separate pulses as it should be.

I've been too lazy to adjust my brake pads lately. Now I must take care of it.

Thanks to all who responded.
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Haluk Okur - Istanbul Turkey