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Speedo adjustment after changing sprockets?

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Linux_insidev2, Aug 16, 2007.

  1. Hey guys,

    I've heard that you need to recaibrate after a sprocket size change to maintain a correct reading, what i don't understand is this-
    The speedo cable is driven by the front wheel, regardless of the sprocket size on the back the speedo reads how fast the front wheel spins.

    No matter what you do to the back end, it shouldn't effect the speedo because all it measures is the front wheel right?

    If this is so, why is it recommended to get the speedo adjusted to match?


     
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  2. because it changes the final drive ratio? I dont get it either. But I know if you change your profile of your tyre it can change the speedo (obviously.)
     
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  3. If your speedo drive comes from either the front or rear wheel your indicated speed does not change, no matter what you do to the sprockets. This is only required if you have the speedo being driven from the gearbox.
     
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  4. From my recollection the ZZR250 is a front wheel driven speedo so no worries about the speedo changes.
    You can check this by looking for a black tube running front the left hand side of the front wheels axel up towards the back of the instrument cluster.
     
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  5. That's right :p

    I had to replace the bugger once because it snapped :(
     
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