ezoons

I've just got myself a Cateye Mity 8 (wired) computer, and I've noticed that whenever the magnet passes the sensor (going backwards or forwards), something emits a subdued clicking noise. I suspect it's the sensor.

Is this a feature of these computers or is it just a loose something (pretty sure there's no rubbing anywhere)?

Ingleside

Its normal. My micro wireless does the same thing.

carpediemracing 

The pick up has a small switch in it. When the magnet passes by, it closes or opens the switch (not sure exactly what kind of switch it is, but I would guess an "always open" one).

Good catch actually, I only discovered this when I had a bike on a stand and I'd just gotten an education on building security systems (including "always open" and "always closed" switches for doors, windows, glass, etc).

hope this helps,
cdr

Campag4life

All a bike computer is...is a "counter" for distance measured against an internal time clock for speed. The click is a reed switch opening and closing due to the magnet passing by and sending the rate of counted pulses to the receiver unit on the handlebars. If you have the Micro like I do that rate of pulse is sent via radio waves versus discrete wire.
https://en.wikipedia.org/wiki/Reed_switch

ezoons

Who would've thought! I used to have a Schwinn wired computer, but its sensor was quiet. I guess they used a different switch there.

Never thought about a reed switch.