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Help me make sense of this..

I know the speedo is optimistic from the factory. I'm +2, so now it's really off. No speedohealer yet.

I set the trip meter from a stoplight to my girlfriends driveway on my 636, and it measured 5.3mi. I did the exact same thing on the following day in my car, and measured 4.9. Based on those numbers, my odometer is ~8% "fast."

Now, the question.. Is there a direct correlation between speedometer and odometer? Is it safe to say my speedometer is 8% off as well? Or is there something else metering speed?

I hope this makes sense..
 

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I have an 06 636, I went +2 on rear sprocket and stock front sprocket. I took my GPS out on a ride and found that my speedo is about 5 mph fast. When I am doing 40mph on the speedo, I am actually only doing 35 mph. When I am doing 80 Mph, I am actually only doing 75 mph. Like I said, that is GPS verified both with a Garmen IFinder and a Garmen Nivi 200.
 

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+2 rear sprocket and only off 5mph at 80mph? that for some reason just doesnt sound right.
from my riding and verification with radar, with stock gearing 50mph was 45mph and 100mph was actually 89mph, but of course tire pressure can play a small part as well.

as stated the speedo and odometer are run off the same sensor.
 

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I have to disagree with the speedo and odometer run by same sensor. My understanding with the DOT is that the Odometer by law has to be dead on from the factory, but with our bikes (more noticable then cars, don't ask me why), having the odometer dead on causes our speedo to be off up to 10%.

JD....I have varified my speedo with both my GPS units, my local LEO (State, City, County) and all 3 of my vehicles (05 Grand Prix, 06 Jeep Grand Cherokee and 08 Honda Civic Hybrid) and at 80 Mph indicated, I am doing 75 Mph actual, with M3 tires filled to mfg. specs. I drive the same route everyday for work and run across each of these LEO, they have all clocked me at one time or another and I was always indicating about 5 Mph over what I was clocked at. Now at higher speeds there will be a greater spread but when I was clocked at 85 Mph actual, my speedo indicated about 91 Mph. Each bike will be somewhat different and I highly incourage checking your own bike with a GPS.
 

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my buddy has a speedo healer on his gixx750 & we were pacing each other the other day & mine was exactly 8mph off & i'm -1/+1 in sprockets
 

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I'm -1 up front, on average, when I am in 6th gear my rpm = my mph

6000rpm = 60mph
7000rpm = 70mph
8000rpm = 80mph

per GPS
 

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I have to disagree with the speedo and odometer run by same sensor. My understanding with the DOT is that the Odometer by law has to be dead on
How do you propose the odometer gets it's values?:confused:

I would be very..VERY surprised if it was anything but a simple logic program used to calculate time vs speed into distance traveled. So I do believe that odo will definitely be off.

I think its safe to say we don't have any hidden hall effect sensors on our wheels. well..unless I'm blind. The rest is logic. Taking that into consideration; whatever the sensor is picking up on, it is before the output shaft of the tranny. Like it or not a changing in sprocket ratios will affect the rpm of whatever the sensor is picking up on, for the same speed traveled. So unless there is something actually picking up wheel speed, we can pretty much say for sure the odo will be off.
 

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Powerhungry
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How do you propose the odometer gets it's values?:confused:

I would be very..VERY surprised if it was anything but a simple logic program used to calculate time vs speed into distance traveled. So I do believe that odo will definitely be off.

I think its safe to say we don't have any hidden hall effect sensors on our wheels. well..unless I'm blind. The rest is logic. Taking that into consideration; whatever the sensor is picking up on, it is before the output shaft of the tranny. Like it or not a changing in sprocket ratios will affect the rpm of whatever the sensor is picking up on, for the same speed traveled. So unless there is something actually picking up wheel speed, we can pretty much say for sure the odo will be off.
yep..

and i dont believe the odo is accurate when stock either...

also to the OP.


cars will be off aswell.

i think theyre allowed up to 5%(maybe its 7) of varience, when NEW.

so you cant always tell by doing pacing a car. several, and getting an average..ok maybe..
 

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also there is no mention of any other related sensor to the odo, and nothing in the electrical diagrams, also no mention of odo input on spedo/ecu terminals, all terminals accounted for.




edit: also an odo will always be off no matter what. It is impossible for it to take into consideration tire wear, and in consequence tire circumference..
 

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well it's easy to see if the odo and speed are linked - don't even have to take the tank off (unless they changed it after my 04 bike), just unscrew the sensor out of the sprocket case cover and watch nothing work as you fly down the road..
 

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well it's easy to see if the odo and speed are linked - don't even have to take the tank off (unless they changed it after my 04 bike), just unscrew the sensor out of the sprocket case cover and watch nothing work as you fly down the road..

it has been changed, see above pic, but I do agree that unplugging the speed sensor will result in no speed value being displayed, and no increase in mileage.
 

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I have to disagree with the speedo and odometer run by same sensor.
Same as Tristan says. If you disconnect the speed sensor on the engine the speedo and odometer stop working. If you disconnect the 1 wire going into your gauge cluster the speedo and odometer stop working. Now somewhere it does math and turns speed into distance traveled but they both get input from the same sensor on the bike everything else is calculated.
 

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if you wanna get real trick, about it's math, it'll even convert your miles into kilometers when you change it, and change it back again.. clever stuff.
but yup, all run off one sensor. And it's not rocket science to figure out how far you go by how fast you're going. Think about it; miles per hour.. how many miles in one hour. If you're doing 50 miles per hour, you'll clock up 50 miles in one hour. Vary the speed, and you vary how far you've gone. It works it out, not hard.
 

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Discussion Starter #16
nevada;1316056 cars will be off aswell. i think theyre allowed up to 5%(maybe its 7) of varience said:
edit: also an odo will always be off no matter what. It is impossible for it to take into consideration tire wear, and in consequence tire circumference..
I wasnt expecting the car to be dead on either.

I'm looking for more of a ballpark figure than anything.

I agree that it's one sensor. I'm assuming it calculates the RPMs of the output shaft and crunches that number twice, once for speedometer, and once for odometer.

My original post wasn't meant to take two sensors into consideration.. It was more to ask if Kawi had a bullshit correction in there somewhere, resulting it an optimistic speedo and accurate odo.
 
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