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Speedo Callibration?

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warren3200gt
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Speedo Callibration?

#1 PostAuthor: warren3200gt » Fri Sep 01, 2017 2:45 pm

Guy's, is it poss to calibrate a std speedo? Just been out on one of my 650's and thought Id check how optimistic the speedo is. I downloaded a sat speedo app then strapped the phone to the bars. At app 30 speedo's reading 35, at app 50 it's showing 60 and at app 70 it's showing 85. So 20% OTT. Out with fine line tape for now but would like a little more accuracy than that.
PUM 488 June 20
76 Z900A4, 77 Z650B1, 77 KZ650B1, 77 Z1000A1, 82 Z1000J2, 89 ZXR750H1, 92 Blade RRN

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tlc
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Re: Speedo Callibration?

#2 PostAuthor: tlc » Fri Sep 01, 2017 4:13 pm

Another interesting question here.
Most speedos read 3mph over to ensure a margin of error I assume.
I saw 150 on mine last Sunday but think 140 was more likely. I didn't have my sat nav connected so can't be sure.

I think many problems arise from different tyre profiles being used from that which the manufacturer intended.

Is yours much different?
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warren3200gt
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Re: Speedo Callibration?

#3 PostAuthor: warren3200gt » Fri Sep 01, 2017 4:59 pm

Standard width and rim diameter 325 x 19 avon roadrider. Not sure about profile though. It would have to be significantly smaller though to read 20% high surely and roadriders aren't particulaly low profile.
Does anyone offer a refurb / calibtation service? Thinking the oil damping could be low and needs a refill.
PUM 488 June 20
76 Z900A4, 77 Z650B1, 77 KZ650B1, 77 Z1000A1, 82 Z1000J2, 89 ZXR750H1, 92 Blade RRN

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Captain Custard
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Re: Speedo Callibration?

#4 PostAuthor: Captain Custard » Fri Sep 01, 2017 7:47 pm

Mine always seemed to be saying 80mph whenever I went out so I sought out some of the temporary 'check your speed' signs we have in the villages around here in rural lincs and low and behold my speedo was quite accurate. :D
Joking aside these radar based signs are quite accurate if you note the Rev counter reading and divide the Revs by the speed indicated on the sign you can check your speedo accuracy at any speed. You obviously need to be in top gear eg - 2k revs = 30mph - 6k revs = 90mph etc. You need to repeat it several times to get a good average but it works as a quick check. :wink:
Last edited by Captain Custard on Sat Sep 02, 2017 12:54 pm, edited 1 time in total.
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warren3200gt
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Re: Speedo Callibration?

#5 PostAuthor: warren3200gt » Fri Sep 01, 2017 7:59 pm

He he, that made me chuckle. I have and can easily verify how much its over reading by using the sat app speedo on the phone. It would seem sorting the existing speedo is a bit hit and miss so I'll probably makeup an overlay for the face.
PUM 488 June 20
76 Z900A4, 77 Z650B1, 77 KZ650B1, 77 Z1000A1, 82 Z1000J2, 89 ZXR750H1, 92 Blade RRN

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jonhunt
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Re: Speedo Callibration?

#6 PostAuthor: jonhunt » Fri Sep 01, 2017 8:24 pm

Mine consistently reads about 10 mph over once you get over 40

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Z1parR
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Re: Speedo Callibration?

#7 PostAuthor: Z1parR » Sat Sep 02, 2017 8:00 am

At a GPS reading of 70 my Z1B reads between 65 and 80 .
However at a true 100 on GPS the speedo reads between 70 and 85 .
Hope this helps .
It's good eye exercise if nothing else :wink:
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Garry.L
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Re: Speedo Callibration?

#8 PostAuthor: Garry.L » Sat Sep 02, 2017 9:20 am

Z1parR wrote: However at a true 100 on GPS the speedo reads between 70 and 85 .


Honestly Officer...
ʎɐqǝ uo pɹɐoqʎǝʞ ɐ ʎnq ı ǝɯıʇ ʇsɐן ǝɥʇ sı sıɥʇ

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Z1parR
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Re: Speedo Callibration?

#9 PostAuthor: Z1parR » Sat Sep 02, 2017 10:17 am

Garry.L wrote:
Z1parR wrote: However at a true 100 on GPS the speedo reads between 70 and 85 .


Honestly Officer...



:lol: :lol: :oops:
0172 . Geoff Parr

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Charlie
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Re: Speedo Callibration?

#10 PostAuthor: Charlie » Sat Sep 02, 2017 12:47 pm

To answer the actual question:

No there isn't. At least not cheaply. You could buy a Smiths calibrated dial but then it isnt standard.

Electronic digital speedo's can be calibrated to read accurately by using speedo healers and the like, but not standard Zed clocks.
Why do I persist in debating with idiots ? I really should know better :)


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