Speedo Error Correction?

So here is a question for the group. Is there a way to use the spedo healer and only isolate the spedo wire and not effect the odometer? The reason I ask my odometer is only off about 2%
 
Photo Man said:
... Is there a way to use the spedo healer and only isolate the spedo wire and not effect the odometer?
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Nope. Both the speedo, and the odometer, derive their input from the vehicle speed sensor output signal. You change the speed sensor signal (which is what you're doing with a speedo-healer), you effect both. No way around it... unless you were to somehow incorporate a second speed sensor into the gear box. It's either that, or re-engineer the instrument cluster internals (which you'd have to do anyway, if you added a second speed sensor). I've been inside a few Honda instrument clusters. Near as I could tell, there's a single, monolithic, microcontroller, into which the speed signal is routed. So, no chance to intercept, and split/change/reroute the signal for only the speedo, but not the odo.
 
speedometer accuracy

I just bought a 03st last week and hooked up my zumo550 gps off my goldwing. My speedo is off about 5 miles per hr. @ 70mph. Its reading fast. My 2000'se 1500 is right on with the gps. Is this common with the st ?
 
Re: speedometer accuracy

I think it is. It seems to me that around 3-5% error (usually reading fast) is built into most speedometers.
Other factors like tyre size, inflation pressure, wear and weather conditions can affect readings.

I don't find it a problem in day to day use, especially if you know the speedo read error after checking with a GPS.

(. . . . and thanks to George and the link. Lots of good info there, I jumped in the pool too early :))
 
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dduelin said:
Garmin GPS units were updating about every second when they went from single channel multiplexing receivers to 8 or 12 channel receivers about 15 years ago. I don't know how fast they update now but it is at least 60 times a minute for my five year old 2730. The spec is in the owners manual.
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I ride corrected...... (pun fully intended....)

When I used to look after Police systems, the delay between what was being displayed and actual speed was between 0.6 and 0.9 seconds, which was crucial in some Police accident (Polac) investigations.... that wasn't satnav though, but a similar sort of system used in the 1300 speed indication.
 
Firstpeke said:
I ride corrected...... (pun fully intended....)

When I used to look after Police systems, the delay between what was being displayed and actual speed was between 0.6 and 0.9 seconds, which was crucial in some Police accident (Polac) investigations.... that wasn't satnav though, but a similar sort of system used in the 1300 speed indication.
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Without Garmin information to the contrary I would agree with this delay when speeds are rapidly increasing or decreasing. On occasion I may be accelerating rapidly to pass a slower vehicle and see a certain number on the speedo readout on the GPS, say 77 mph for example. At that glance I complete the overtake and I come off the throttle and back it down to 70. The Max Speed readout may read 81 mph when I look at it later in the day. It is not that the GPS speedometer is inaccurate just that there is a small lag between measured and displayed speed.
 
iirc plain vinalla civilian GPS chips update once per second.
afaik they don't figure in rate of change from preceding calculations and modify the distance/time calculation.
i think aviation are closer to 10 per second.
 
Mark said:
I don't think it's a "screw-up" since police bikes have speedos that are right on...
I agree it's a pain; but, it has to be by design.
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I would assume they were, given it could cost you a ticket, or your liscence. But as a friend of mine is in the industry of fitting out police cars, he has told me that they are just cars off the factory floor, the speedo is not touched and can be off too. As for my ex-police st1100 it reads 100km\h on the speedo but is doing 115km\h according to not only a GPS, but another bikes speedo which is known to be closer to accurate.
 
Using a different profile tyre than the standard fit on the front of the 1100 will affect the speedo reading
 
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