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I bought my 03 Wing at 35000 miles 2 years ago.It now reads 73400 miles.In 2010 I rode 12000 miles long distance in 3 months.The GPS read just over 10,000 miles.This is close to 20% less mileage than the bike shows.This Summer again close to 12000 miles but this year I clocked individual legs and again the same discrepancies.
This would mean the GPS has to be correct thus the Wing in effect has done approx 20% less true mileage but then using the same math I am not getting 43 miles per gallon on average but 20% less.I do know that when I am doing 70mph on the bike the GPS is showing 65 which I was given to understand Honda did that on purpose which would be approx7% different.
Has anyone experienced similar.
 

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Japanese motorcycles have always had that discrepency. Back in the 70's, 80's 90's motorcycle mags always gave the percentage the speedo was off in their articles. Everyone knew it but didn't give it any thought. Now the GPS generation gets all upset about it, but it's nothing new.:shrug:
 

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maybe

Ivor,

I don't think that there is that much difference. I know that on my Garmin, when I put in a potential destination, it gives me line-of-sight measurement to the position. I don't get road mileage until I actually make it a destination or way point. I didn't realize that at first and was taking longer (time and miles) than I expected. Perhaps your totals are being short-cutted for the same reason/way.:shrug: I do agree that there is a difference between odometer and gps miles. You could probably subtract that 6-7% and be very close.

Richard
 

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The early 1800's speedo and odometer were off. My 02 and 08 both added 1 mile every 25 according to my GPS. You can either buy a speedo healer and correct that or I put a 70 series tire on the back and my speedo was right on and my odometer read 98 miles for every 100 traveled by the GPS.
 

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I checked my 08 against a GPS and the difference was 90 miles in 3000 actual miles or 3%. No big deal. 20% something is very wrong there.
 

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Would changing to a taller tire make a difference? Aren't 70 series tires taller than 60 series?
 

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I agree that a 20% difference is extremely out of the ordinary. I've checked my odometer many times with the mileage markers and find that mine is off 3.5% to 4.0%. I can live with that. Something is wrong with either your calculations, the GPS readings, or the phase of the moon if you're getting errors of 20%.

A 70 series tire will pretty well correct the standard error that earlier model Goldwings have. If I were you I'd do a little more homework on why your readings are so different.

Glen
 

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The gps can also lose signal from time to time. Tunnels, trees or mountains can affect it's signal. Sometimes I will be riding a mile or two before the gps picks up a signal in the mornings.

Just some thoughts.

I'll bet if you figure the difference on shorter trips it will not be the 20% you are seeing over a year.
 

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The gps can also lose signal from time to time. Tunnels, trees or mountains can affect it's signal. Sometimes I will be riding a mile or two before the gps picks up a signal in the mornings.
true, but when the signal is recaptured it will calculate the distance from where the signal was lost.
 

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70 profile tire on my '08...

Error on rides is right around 28 fewer miles (on odo) than actual (GPS) per 1000 miles ridden.

When I ran a 60 profile tire (it was brand new rubber, and already on the bike, when I bought the replacement bike from the previous owner), I believe the odometer was off by about 6% more miles than actual.
 

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I calculated both odometer and speedometer vs two GPS units and found my speedo reads 5.5% high while my odometer reads 3.26% high. Got to wonder why the manufacturers can sell vehicles with that type of variance when the LEO's can ticket you for 1 over if they are having "a day"

I debated a speedo healer unit but am now considering a ct that would correct much of my variance.
 

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true, but when the signal is recaptured it will calculate the distance from where the signal was lost.
I thought this also but after watching it closely my Zumo 550 does not do this. If I start riding before the Zumo fully boots and acquires sat's it will not log any of the distance I have traveled during that time.


Pete
 

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maybe true but

true, but when the signal is recaptured it will calculate the distance from where the signal was lost.
Even if it does recapture how would it know what route you took while it didn't know where you were? It would have to either "guess" which route you took or straight line it from your last known location. I'm betting it straight lines and to save memory capacity, it may do that for all of your history. Just line of site between waypoints. In my opinion that could account for a 20% difference.

Richard
 

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I just had new tires put on the bike, and I installed a 70 series rear. I hadn't measured the diameter of the old vs. new rear tires, but now, the speedo and the GPS are less than 2% difference (? someone check my estimated figure).... The GPS reads 50, and the speedo reads 51. :thumbup: really close to one another now.
Steve F
 
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