Speedo off

Discussion in 'Touring Models' started by dogdad, Sep 20, 2010.

  1. dogdad

    dogdad Active Member

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    I ran my bike with the GPS and noticed my speedo says I'm going 4 miles faster than my gps shows. The gps matched my truck speed ,,so is there anyway to adjust the HD speedo?
     
  2. dbmg

    dbmg Experienced Member

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    Most all speedos are electronically controlled and calibrated to read a 5 mph variance. There is no way to adjust speedo. Check to make sure bike has O.E. size tires on it.
     
  3. Jack Klarich

    Jack Klarich Expert Member

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    What he said:s
     
  4. kemo

    kemo R.I.P

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    That is the way manufacturers protect themselfs from law suits from people who will say that their speedos are reading wrong. I think 6mph + is the allowable error. It also makes your odometer read higher making your warranty run out quicker.
    kemo
     
  5. karbar99

    karbar99 Member

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    I thought the initial HD warranty was 2 yrs, unlimited miles??
    Nothing to do with miles, although I may be wrong again..:unsure
     
  6. Hoople

    Hoople Account Removed

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    Now mine is the opposite. My speedo is perfect (near perfect) but my odometer is 5% off (2 miles off for every 40) which is a joke to me. I can understand the speedo being off but as long as I am still using the original tire/size on the bike as it was delivered, the odometer should be perfect.

    Your right it is. I think Kemo was just saying it as an expression of speech.
     
    Last edited by a moderator: Sep 21, 2010
  7. kemo

    kemo R.I.P

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    Thanks Hoople you are correct. When I was a younger pup I worked at one of the Ford plants and one of my jobs was the rolls test which is basically a dyno machine. We had to run every car and check transmission shifting and check the speedo against the big master speedo, we checked signal light operation and wiper and washers, and heat & A/C functions,all the lights, checked for drive line vibrations and noises. The cars had no interiors in them so we had to car a little stool with us and latch it into the floor.
    kemo
     
  8. gs34

    gs34 Junior Member

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    Any measuring device is manufactured to operate within a tolorance. This is normally shown as a percentage
    As of 1997, Federal standards in the United States allowed a maximum 5% error on speedometer readings.
    There are too many variable that figure into the accuracy of a vehicles speedometer.
    Speedometer - Wikipedia, the free encyclopedia

    The only way to assure 100% accuracy is to calibrate to a standard everytime an instrument is used. In the case of a vehicle speedometer, that is not a realistic option.

    If maintaining a steady speed, the GPS speed will be more accurate than most speedometers.
     
  9. Hoople

    Hoople Account Removed

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    If you really really want to offset the speed error you have with your speedo, it can be done. There are small electronic interfaces (~$100) that take the VSS output and shift the frequency in the direction you need.

    The problem is you can not offset the speed error without affecting the odometer. So in most cases you correct one issue and create an error in a different area.
     
  10. texasgrinch

    texasgrinch New Member

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    OK, I got the same problem to on my 08, Hoople said by using a small electronic interface, you can shift the frequency,,if you can slow down the speedometer, wouldnt that also slow down the odometer? My GPS says I am 5 fast at 70(shows 75). On my 98 Ultra, GPS is dead on, at 70, GPS goes from 69.7 to 70.2, i know the 98 is cable drive, but how dod you get thingy to change the freq?