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speed calibration

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by davey_charlie, Jun 8, 2010.

  1. hey guys,

    my speedo is way off. saying im doing about 125 kmh when im actually doing around 110 kmh.



    is there a place in melbourne that will calibrate it?
     
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  2. most bikes are like that but not by that much
     
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  3. Common with motorcycles and mine is the same.
    Take off 10% for the correct reading.

    Seems this is purposely done by motorcycle manufacturers.
    Never heard an official reason why though.

    I know a netrider with a Ninja 250 had the same thing and had it calibrated under warranty although they tried to persuade her out of it.
     
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  4. yeah just don't want to be speeding/ guessing my speed i'd rather have it 99% accurate then get fined.
     
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  5. did u test it via GPS or next to a car?
     
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  6. next to trucks and cars, it was going slower than trucks with 100 limited at 110 kmh. seemed to be about right at 5000rpm in 6th at 125kmh. a friend who has a vtr 1000 f says his does about 110 at 5000 rpm
     
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  7. ADRs. The manufacturer is required by law to read the actual speed plus 10%, with no allowance to indicate below actual speed. Previous ADR was to indicate true speed plus or minus 10%, now the manufacturer is in breach of ADRs if it is not 0 to +10%.

    If that makes sense!
     
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  8. anyone know of any ifone apps that records speed?
     
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  9. ive got a gps, but im abit scared of it falling off and smashing as it was quite an expensive one. a free iPhone app would be good to figure it out
     
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  10. You could carry it in your pocket, davey. The GPS doesn't need to see the sky perfectly to receive the signals, it should be able to read through a tankbag, backpack, jacket pocket, etc.

    I would recommend testing it on a flat, straight piece of road, as corners and hills can throw out the speed calculations. (Based on my experience with several bushwalking and other GPSes from Garmin, for example, they treat horizontal velocity and vertical velocity as two separate things).
     
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  11. gps doesn't log the speed though, i would have to be looking at it to check
     
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  12. They have been round for a while but you can get a device called a speedo healer which only works on electronic speedos ie like yours. Never used one myself and the R1 speedo lies its teeth off.

    Check this link out.
    http://www.amcmotorcycles.com/contents/en-uk/d334.html

    Hope it helps
     
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  13. gs500 has an analogue speedo, and those healers don't work.
    Speed is taken from the front wheel.

    I've read on other forums that some put a larger 110/80 tyre when it's time to replace as opposed to the stock 110/70 which brings the speedo a little closer. But this is another topic all together.
     
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  14. My GPS has data logging, including speed, but it is only average speed over a distance. That distance can vary from 50 metres to 200 metres (or thereabouts) and produces a speed for that particular sector. Useless for arguing in court, but over a distance with cruise control set and a steady speed, it gives a pretty accurate indication of my speedo's accuracy: or lack of accuracy ;) Good enough that I'm confident of my speeds when passing cops with hairdryers, or unmarked camera cars at revenue collections points....
     
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  15. What brand of GPS is it? Can't connect it to a PC to download the track file for examination?

    But that's how GPS works - it knows where you were (within ~5-10m accuracy) at one point in time, it knows where you were (within ~5-10m accuracy) at a later point in time, speed is distance over time, et voila: your average speed over a 30-200m distance. GPS has no means of knowing your instantaneous speed, it's always displaying an average speed over the previous 1-2 seconds.

    I daresay that evidence you were at one point of a 110kph speed limit road at 10:00:00am, and 4 seconds later you were 120 metres further down the road, is pretty good evidence that you're not speeding. At 10:00:08 you were 240 metres, at 10:00:24 you were 920 metres... And at 10:05am you were 9km down the road, still travelling at just under 110kph. Especially with the emphasis on average point-to-point speeds nowadays.
     
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  16. cool i will check this out thanks, but surely there would be a workshop that would be able to calibrate speedos. mine is digital and speed sensor is on the gearbox.
     
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  17. If you can't find anyone willing to calibrate for you (though they should after waving money at them)

    Another option is to get something like a bicycle speedo. It works the same as any other that reads the front wheel.
    Sensor + place magnets around the wheel to pass over the sensor and then calibrate to your rolling tyre diametre with a little digital display on the dash.

    Dad used one on his girlfriend's GN250 as the stock speedo was buggered and it was cheaper than replacement (already had it lying around too)

    It's supposed to be accurate to within 1-2% and will display from 0-199km/h
     
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  18. all GPS have a maximum speed attained record.

    Go out to a freeway and travel at 100kph (not over) stop and take a look in
    STATS it will tell you your max speed.

    You can work out speedo error from there.

    (Wonders when the police will be able to use that against you, don't forget the reset).
     
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  19. What a great idea. Never thought of that. =D>
     
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  20. if you need a temporary gps and you have a car gps.. just attach the suction cup to the tacho on you bike...
    otherwize tape it to your tank..
     
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