Digital speedos are 100% accurate

[5v3d3b0]

Someone on youtube got 172 kph out of their new rs 125. I explained that the speedos are not accurate and you can take off roughly 10% of top speed for a true speed.
This is what he replied:

[rainer]

Nah i've got a mate and his does 203mph downhill. Trust me I'm 17.

[Kickstart]

Hi

You are missing nothing. He is missing the point that with an analog speedo the cable is the least of your worries for accuracy.

Tyre pressure and tyre wear are the most likely causes of it becoming innaccurate. But the makers only have to produce them to give vaguely accurate readings.

All the best

Keith
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[Fnatic]

I've got the RS 50 version with the digital clock and it gives similar readings to all other mopeds within 5 mph so it's probably more accurate as it discounts misreadings of an analogue speedometer but just as accurate as analogue.

[Pete.]

My 'busa on stock gearing was indicating 215mph - but the timing ticket read 193

Another interesting observation:

I have an OBD2 scanner & datalogger that I plugged into my works van for a test. Whilst driving, the VSS (vehicle speed sensor) output read exactly what my GPS was showing, but the speedo was showing 5mph higher (as have all of my company vans (VW Transporters) over the years.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[map]

Basic physics means that any instrument cannot be 100%. It's down to how close it can get to that.

As said by Kickstart basic wear and tear affect the reading as well as environmental conditions etc. etc. etc.

The guy is a jerk for believing such twaddle, probably brainwashed by the digital readout without thinking how an analogue motion gets converted.
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[Frost]

Speedo's can be spot on, but only on certain bikes, at legal speeds with brand new tyres at the correct pressure carrying the perfect load.

As a general rule the smaller the bike the shitter the speedo.

[Ariel Badger]

[kitty kat]

How come in my car today, my digital speedo said I was doing 70mph, another car overtook me, I could clearly see his speedo was registering 70mph, yet he was going faster than me? Digital speedos therefore cannot be accurate.
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[map]

[Pete.]

Speedos have the potential to be 100% accurate but what they cannot do is allow for tyre wear, or more significantly for bikes - tyre growth! Tyre diameters can increase significantly at speed. If you ever get to view a bike on the dyno you would see it for yourself.

Avon produce a 'zero-degree' tyre carcass that restricts tyre growth, as do other tyre manufacturers.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Skudd]

My speedo on the bike is about 10% out from my sat nav ( Garmin)which is sometimes 9 feet or 67 feet accurate. Sometimes I could be sat still and the sat nav will show I'm doing upto 0.9 mph.
all speedos are approx it just that some are more approx than others.
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[Ariel Badger]

Both speedos were correct for the data that was being inputted into them, the manufacturer will of course program the speedo to give a higher MPH than is actually true and this will give a false distance reading as well. This serves two purposes...
1.It makes the vehicles performance seem better than it actually is.
2. It makes the vehicles fuel consumption seem better than it really is.
The speedo is reading false input data very accurately.
You know those time boards on the London underground that tell you how long the next train Will be? Well...when they say 4 mins they mean 4 London Underground mins not real ones try timing them with a watch they can be up to eighty seconds long. This gives the impression that the service is better than it actually is.
It is not the clock that is inaccurate but the person who programed it has done so to falsify the outcome.
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[leddy500]

[Fnatic]

My RS50 indicated 70mph on the digital speedometer today.

Does this mean it's not 10-15% out then

Closer to 60mph I think

[Finglonga]

[ms51ves3]

[rainer]

[neil.]

When I compare the speedo on my YBR to the readout from the TomTom, both are exactly bang on the same at all speeds (well 0 - 65ish)... Must I be blessed?
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CBT February 2008 | A2 June 2008 | Yamaha YBR125 (written off) | Honda CBF125 (current)

[panrider_uk]

[Knacker]

Well your all unlucky my GS speedo used to under read i think and i actually was doing 160+ and not actually 57 i mean it was well off the redline like

I new that bike was a sleeper
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Current: Gsxr 600 Srad - GS125 - DT125
Previous: K1 GSXR 1000

[MarJay]

[Mr Nice Guy]

[Kickstart]

[panrider_uk]

https://www.pocketgpsworld.com/index.php

A useful site for GPS users.

Mark
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Current bikes: Honda ST1100 Pan European. Moto Guzzi V85 TT Travel