Tesco wired computer


New Member
Has anyone bought/used/returned one of these? Its supposed to do (among other things) speed, avg speed, and also cadence. I tried to set mine up last night on the bike but on the commute this morning it didnt register an RPM, cadence, and my speed was apparently 3.8 mph.

Is there a trick to set these things up? Ill try and get some pics up of the system as it is at the moment, but Im thinking of cutting all the cable ties and sending it back if it isnt going to be at least slightly accurate.


Man or Moose!
Make sure the wheel and crank magnets are close enough to the respective sensors (2-5mm depending on the quality of the sensor) and make sure you have calibrated the thing with the right wheel size. Spin the wheel and play about all you need to until you get repeatable reliable results, then you can zero the unit to wipe out all the messing around.

Tesco wired computers have a decent rep for being a cheap and cheerful device.


I brought one last night, for £6.50 i thought i couldn't really go wrong!

Fitted it at 6.30am this morning so have only done one trip but so far it's working well.

Baring in mind this is only my fourth commute in and before that the bike sat rotting in the shed for 2 years i'm happy with my figures.

5.106 miles to work
Time Taken 21:18
14.5mph average
29.2mph top speed (i have a steep hill to come down....lol)

All on my 10 year old MTB fitted with Schwalbe City Jets but with front shocks.

Next up for me is mudguards but then will be saving for a road bike to do it properly!


New Member
See, I paid £14 for the activeequipment (red+black cardboard packaging) version, which I had taken off to send back, but I've lost the reciept. I might try and refit it tonight to see if it works, because Id really like to know my cadence along the route. Have you got pics of your setup? How close together have you attached the sensors and the pickups?
I've two of them Tesco's computers, the wired one which was about £8, and a wireless one which was about £15. The wireless one has wired cadence.

The wired one has worked through the winter without complaint so I'd recommend them.

The wireless one is a bit prone to interference and also gives occasional ludicrous readings from the wired cadence. I got a bit sick of this and in the end just cut the cable off and didn't bother with cadence.

A 2/3mm gap should be fine. Maybe you batteries are a bit flat - is the display nice and black?


New Member
reviving an old topic,

very noob question. Ive had bikes for years but never a cyclometer so please advise.

I have the wireless version. As one of the people above I have removed the cable for the cadence as this annoyed me.

Ive setup the wheel size correctly but how does this work in relationship to location of the sensor and magnet itself. Obviously if the sensor is on the outside of the wheel the rotation speed would be totally different to that if the sensor was tight into the center.

Ive looked throught the absolutely useless instructions but cant find anything. I am receiving readings but not taken it for a ride yet.

Please advise if im missing something other than a brain cell


soulful dog

I queried the placement of the sensor in this thread: Computer accuracy, and some very helpful replies explain that although it's recommended to place it as far away from the centre of the wheel, it doesn't matter as "the computer measures one pass of the censor per wheel revolution, regardless of where it is positioned".


Über Member
Ive setup the wheel size correctly but how does this work in relationship to location of the sensor and magnet itself. Obviously if the sensor is on the outside of the wheel the rotation speed would be totally different to that if the sensor was tight into the center.

It's only counting the time between rotations, not the speed the magnet passes the sensor, so it doesn't matter where you put the magnet because the time between rotations will be constant whether nearer the hub or nearer the rim.


a short-tempered ill-controlled small-minded troll
Beat me to it Bobones!

another possibly daft question... I've had two, the first I had to measure the circumference of the wheel in mm. and key that in.

the next just had wheel sizes in inches to choose from, which i suspected wouldn't be very accurate.

Has anybody found one system of sizing the wheel more accurate than others, or are they both much of a muchness?


Well-Known Member
Anyone with the tesco wired computer help me out, i can't find the instructions anywhere and the wife swears she hasnt binned them (yeah right)
how do you set up the wheel size, i know to reset you either take battery out or press and hold bottom 2 buttons. but dont know where to put in wheel size

You have to do a reset to get the wheel size to come up. You can't changes the wheel size without a reset so you lose all the other data. Then I think it's a right-click to cycle the flashing digit and a left-click to move on to the next one.


New Member
Does anyone know do you have to zero it after every trip and then re-enter time and wheel size before setting off again or can you keep both time and wheel size and just delete last run? only had it a few days nad it is great except for this not a massive problem but not ideal.
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