Electronics, Lighting, & Gadgets - Computer Installation Help

It's a long story but basically I bought a bike computer but before I could install it I found I'm not getting opportunities to ride outside, so I've using it on the trainer indoors.

So I wanted to install this computer I bought a while ago. It's a really basic lowest model, wired job. I've also never installed a bike computer at all.

So I open it up and read the instructions. Seems the sensor is meant to go on the front wheel and fork. Fair enough considering it's wired. But I figure the only issue with putting it on the back wheel is the cable length, which doesn't matter if I have the display sitting on the table next to the bike.

So I set the computer and sensors up, however I am not getting a speed reading regardless of how I fiddle with the position of the magnet and sensor. If I turn the wheel slowly and pass the magnet by the sensor I hear the sensor make a little 'click' noise making me thing something is happening and they are close enough, but still nothing comes up on the display.

Now is there anything else you can suggest trying?
Or is there something a bit silly I am missing by putting the sensor and magnet on the back wheel?

Thanks

Some computers require several revolutions of the wheel to recalibrate and take a reading.

Depending on the make and model there may be an accessory harness available for rear wheel sensor mounting and it will cost signifigantly less than an entire computer...or you can go McGuyver on it and extend the wires yourself...voiding the warranty though.

If you can post the make and model, no doubt someone with specific experience may be able to give you more input.

Thanks.

http://www.fluidbicycles.com/lights.html
The model I have is the one in the bottom right on this page. I bought it as part of the kit with the lights. Unfortunately I can't find any more info around on it. I actually remember seeing the same display casing with a different branding on it so it's nothing special.

As for the revolutions of the wheel. I had actually been spinning the pedals while testing it, so there would have been plenty of revolutions of the rear wheel to get it going.

Is the computer properly in the mount ?

Is the computer properly in the mount ?

It certainly looks like it is.

How about a photo of the pick up and magnet ?