Speedo calibration

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amulheirn
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Speedo calibration

Post by amulheirn »

Hi all - just wondered if anyone has recommendations other than Speedycables for Smiths speedo calibration?

Cheers,Andy
KevinW
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Re: Speedo calibration

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IainS
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Re: Speedo calibration

Post by IainS »

Just make double sure your calibration measurements are accurate, whoever you choose to set up the speedo. It was the only thing I failed the IVA test on; there is zero tolerance for under reading speedos....
Iain
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amulheirn
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Re: Speedo calibration

Post by amulheirn »

Thanks chaps - Speedograph have offered to make the cable, but didnt answer my question about calibration. I will ask again.

I also asked Holden if they could pre-calibrate an instrument for me if I told them what I needed, but no answer from their sales email this week. CAI apparently do calibration services, but I just thought if a dealer like Holden could do the calibration before sending it out it might save postage time and hassle...
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peterc
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Re: Speedo calibration

Post by peterc »

Not sure how you get accurate numbers without the speedo cable.
I measured the distance on the road that the tyre turned a number of revolutions and then counted the speedo cable turns for the same distance.
You would need to be sure on your exact tyre turns per mile to calculate and of course the specific gearbox speedo gearing.
Certainly sounds a good idea to get it done before despatch if you can.
Accuracy should be within +10% and -0%. As Iain had said they won’t accept an under reading.
Peter C
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peterc
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Re: Speedo calibration

Post by peterc »

As an aside the +10% speedo accuracy is where the Police have their ‘36mph club’ for minor offenders. Get caught at 36 and they know you were probably seeing 40mph on the speedo.
Peter C
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