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Cycle computer

Discussion in 'Bicycle Mechanics and Repairs' started by Cycling Naturalist, 31 Jul 2007.

  1. Cycling Naturalist

    Cycling Naturalist Legendary Member

    I know this is a stupid question. However on my commute back home, I noticed that speed was no longer showing on the readout. I stopped and had a fiddle with the detector on the fork but without any success. Got home and spent a very frustrating quarter of an hour fiddling with the magnet and detector to the extent that they were about a micron apart and it still would not pick up the turning wheel and give a speed read out.

    Any suggestions?
  2. Dayvo

    Dayvo Just passin' through

    O' slO'
    Get a new battery! ;) Honestly, it might be that simple.
  3. chris42

    chris42 New Member

    Deal, Kent
    sensor on wheel moved?
  4. TimO

    TimO Veteran

    The contacts between the computer and the mount may be a little dirty, sometimes just taking the computer off and putting it back on can solve the problem. It's best not to use any abrasive on the contacts, since once you start doing that they generally corrode very easily. Something like a small amount of ethyl alcohol, or some other solvent which doesn't leave a deposit may help.

    Of course it could also be that at some point, where the cable has flexed, it may have fractured. If so (i) you'll need a soldering iron, and some experience of using one to make a decent repair and (ii) the breaks always seem to occur at the point were the cable is least repairable, ie at the mount or the pickup. ;)
  5. gbyers

    gbyers New Member

    Always an annoying problem and not uncommon.

    Check the unit on the bar, is there a small contact pin that is required to be pushed in to set unit working (eg Topeak) or metallic contacts. This is a common fault that causes random stoppages.

    If it's a wireless set up then change the battery in the sender unit on the fork and then the battery on the head unit.

    If it did it when you were less than a mile from home on a 20 mile run where you were heading for a PB, bring your heel down on the head unit as soon as you arrive home. It won't fix anything but you might feel better. ;)
  6. Cycling Naturalist

    Cycling Naturalist Legendary Member

    I've done the above, save for changing the battery, which I recall has been in for the last 3-4,000 miles.
  7. gbyers

    gbyers New Member

    Sounds like the battery's time is up after that mileage.

    The topeak unit I had worked for many months after it started playing up just by inserting an energy bar tab foil/plastic end bit between the unit and mount. The contact pin had worn (or the mount had) and it needed a bit of extra pressure.
  8. Steve Austin

    Steve Austin The Marmalade Kid

    if its not picking up the sensor IME its the battery
  9. Keith Oates

    Keith Oates Janner

    Penarth, Wales
    A battery should last more than 3 to 4 thousand miles if the bike is used regularly. I had the same thing last night and it was the contacts, as others have mentioned. Annoying though 'innit'!!!!!!!!!!!!!!!!!
  10. Cycling Naturalist

    Cycling Naturalist Legendary Member

    Particularly as I'm sure that I'm averaging over 30 mph on my commute now. ;)
  11. Christopher

    Christopher Über Member

    +1 for the contacts. I have to clean mine frequently as they corrode readily

    Surely if it was the battery you'd just have a blank screen?

    Have you taken the computer off its mount, Patrick? Are the contacts green or clear?
  12. Cycling Naturalist

    Cycling Naturalist Legendary Member


    The contacts are nice and clean.
  13. wasi

    wasi New Member

    A tip I have from another forum is to insert the battery the wrong way around for a few seconds to reverse the flow of the little electrons. It sounds strange but worked for my Avocet, which displayed the same symptoms.
  14. Lardyboy

    Lardyboy New Member

    You've overtaxed it Patrick that's why its stopped working! :biggrin:
  15. Chuffy

    Chuffy Veteran

    I say Patrick, you seem to have got lost. And you're talking about cycling of all things! Shall I get one of the nurses to take you back to the Cafe? If you're a good boy I'll send Arch round with some Horlicks and a book of Ripping Bedtime Stories For Big Boys.