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Rob, I won't beat the point to death, but it just doesn't make sense. Although you are correct that there must be two different algorithms, both get their input from the same place. (the rotation of the tire) A change in the rate of rotation would have to have the same affect on both devices.

On the other hand, am I making a bad assumption? Does the odometer possible have an input that is not taken from the rear tire rotation?
 
I thought the speedometer and the odometer takes it's reading from the transmission shaft or something..not the rear wheel.
 
Rob, I won't beat the point to death, but it just doesn't make sense. .
I agree, it makes no sense. The speed sensor is mounted someplace on the right side of the engine, I think near the exhaust headers. No speed sensors on the wheels, except for bikes equipped with ABS and as you probably know, those sensors serve a different function.

I would think that reducing the speedometer error by say 4% would have the exact corresponding effect on odometer error. It doesn't. Someone with knowlege of the logic circuit design could probably answer why.
 
I thought the speedometer and the odometer takes it's reading from the transmission shaft or something..not the rear wheel.
I used the rear wheel as an example to keep my question simple, but I wasn't really sure whether it was the wheel or the shaft. But thanks for letting me know.
 
I agree, it makes no sense. The speed sensor is mounted someplace on the right side of the engine, I think near the exhaust headers. No speed sensors on the wheels, except for bikes equipped with ABS and as you probably know, those sensors serve a different function.

I would think that reducing the speedometer error by say 4% would have the exact corresponding effect on odometer error. It doesn't. Someone with knowlege of the logic circuit design could probably answer why.
Not knowing things like this drives me nuts. Now I'm going to have to go look it up.
 
The 70-series rear tire is larger in diameter than the 60-series tire, thereby changing the overall rear gearing, resulting in the speedometer reading correctly. I don't know where the odometer gets its information from, but running a 70-series rear tire apparently corrects the odometer somewhat. When I went to the 70-series tire, I noticed that my gas mileage suffered by about 3-4 mpg. I attributed that to the change in gearing resulting in a change in the number of miles ridden as detected by the odometer. But as to where the odometer gets its info, I just don't know and I don't know how the miles are determined, other than it doesn't seem to have anythng to do with either of the wheels as in the GL1500 which has its speedometer sensor on the front wheel hub.

In any case, the warranty on a Gold Wing is not affected by the number of miles on the odometer, as it is an "unlimited miles" warranty, so I really don't believe anyone is actually getting ripped off in that respect. However, I, for one, prefer to know exactly how fast and/or how far I'm going and not have to interpolate by applying math computations to determine what it really is.
 
I thought the speedometer and the odometer takes it's reading from the transmission shaft or something..not the rear wheel.

Yes; but the ankle bone is connected to the foot bone, so it makes no difference -- the tire size change does change the indicated reading.

prs
 
Odometer readings

I've always determined what the odometer error and speedometer error on every car, truck, motorhome, motorcycle I've owned. This started when I was younger often driving a hundred miles not seeing another vehicle in a very unpopulated state and not having a radio station to listen to. Maybe a little weird but I would do time distance equations in my head. This is easier to do in some states than others but there are distance markers on the road. Highway patrol plane markers are the most accurate. Just compare your odometer to these known distances. Speedometer error just try to knock out a mile a minute. If you have to do 66mph to knock out a mile a minute then you know you have a 10% error at 60mph.
 
Misleading odometer readings

Why does everyone keep mentioning the ECM? The ECM has nothing to do with the odometer. All speedometer and odometer functions are self contained in the instrument cluster.

I haven't seen the inside of a Goldwing instrument cluster, but it is highly unlikely that it contains a flashrom. Any modification would probably involve replacing the microprocessor. In most devices like this, programming is hard coded in ROM in the micro.

Don't hold your breath on a change for the Goldwing. While the speedometer may be off by 5-6%, the odometer is only off about 2-3%. With unlimited mileage, there isn't a warranty issue. There aren't any lease turn in issues with a motorcycle, and a bike with 97,000 miles on it isn't going to be worth any less than a bike with 94,000 miles on it.

From the shop manual
Speedometer does not operate
1. Check that the tachometer, coolant temperature
gauge and fuel gauge operate properly.
• If they do not function, check the power
source line and sensor ground line
(page 20-17).
• If they function properly, go to step 2.
2. Check that the engine control module (ECM)
stores failure code 11 (page 5-16).
• If the ECM stores failure code 11, perform the
troubleshooting on page 5-28.
• If the ECM does not store failure codes, go to
step 3.
3. Remove the combination meter (page 20-17).
Place the motorcycle on its center stand, shift the
transmission into neutral and turn the ignition
switch to “ON.”
Measure the voltage between the White/black (+)
and Green (–) wire terminals of the combination
meter 20P black connector.
There should be 0 V to 5 V pulse voltage while
slowly turning the rear wheel by hand.
• If the pulse voltage appears, replace the
meter/gauge assembly (page 20-19).
• If the pulse voltage does not appear, check
for:
– open circuit in the White/black wire
between the combination meter and speed
sensor

– loose or poor contact in the related connec

 
I've always determined what the odometer error and speedometer error on every car, truck, motorhome, motorcycle I've owned. This started when I was younger often driving a hundred miles not seeing another vehicle in a very unpopulated state and not having a radio station to listen to. Maybe a little weird but I would do time distance equations in my head. This is easier to do in some states than others but there are distance markers on the road. Highway patrol plane markers are the most accurate. Just compare your odometer to these known distances. Speedometer error just try to knock out a mile a minute. If you have to do 66mph to knock out a mile a minute then you know you have a 10% error at 60mph.
Nowadays most people just use a GPS. Far more accurate, and easier too.
 
LARRY.... gps Is accurate no doubt... But I dont have it on my bike all the time so I installed some gizmo a few years ago. Plug and play but no idea what brand. Chit woudlnt know how to remove it now after all these years,,, cant recall what I did yesterday.

Im glad to hear they have corrected the issue. I knew they could, My Harley is spot on adn all my friends harleys are spot on so I knew it could be done.
 
My mistake for not being more clear. My comment about the GPS was from the standpoint of using it as a tool to determine the accuracy of the odometer and speedometer on the bike, not using it as a replacement for the bike's gauges.
 
I used the rear wheel as an example to keep my question simple, but I wasn't really sure whether it was the wheel or the shaft. But thanks for letting me know.
The reason for some bikes having speedos and odometers that don't agree perfectly is that the analog speedometer is NOT a precision instrument and the needle CAN be mounted slightly off kilter (thus the odometer doesn't agree to laboratory precision).

Also, who can accurately read an analog speedometer within 1 mph and compare to a GPS while riding?? :shrug: The odometer IS a digital device and therefore can be calibrated accurately without head tilt and sun error on a gage face..

Correct the odometer if you feel the need and use the GPS when you need speed readings within 0.1 mph... :roll:
 
Dave, mechanical error is not the problem. While it is true that vehicle gauges are not exactly precision instruments, they are far more accurate than you might think.

If what you were saying is true, then the speedometer would be off by the same amount regardless of your speed. In our case, the amount of error increases as the speed increases. The percentage remains the same.

Also, if you have watched the speedometer threads over the years, our speedometer is off by roughly the same amount on nearly every Wing. That indicates a built in calibration error, not a mechanical tolerance issue.

The innacuracy is not with the gauge itself. It is the calibration that is built into the cluster that is off.

I serviced GM/Delco instrument clusters years ago.
 
Speedometer Error

I have always been kind of annal about speedometer error. I don't really care that much about odometer error. Transmission shops have always told me to determine the odometer error and they would provide a new gear or after market converter (mechanical systems). They continued with you correct for odometer and "hope the speedometer is correct". I typically never followed that advice. I have always determined what the speedometer error is at 60 to 70 mph then corrected to that. Nowadays I find all my speedometers except on Honda vehicles are fairly accurate across the legal speeds. Also I have GPS's mounted in them or on them anyway. Also in new hotrods all we have to do is drive the vehicle exactly one mile (at any speed) in calibrate mood and this calibrates the odometer and speedometer to that car with that tire size with whatever air pressue with whatever ambient temperature with whatever whatever whatever and have an accurate device for that day that matches the GPS and time distance tests over known distances exactly. I'll have to admit that doing time distance tests with a watch on a motorcyle is somewhat difficult but if you are in the middle of Nevada or Wyoming on 80 what else is there to do? Seriously since I have a gps I don't do that much anymore except to prove to myself that gps's are accurate.
 
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