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Hi,

I observed that the speedometer on my 2007 Kawasaki Classic 900 LT is off by 12%. The speed shown by the speedometer is more than the actual speed I see on my GPS. I am assuming that my GPS speed is accurate. I heard that this is a known issue.

If that is the case, is the ODOmeter also problematic? If my Odometer is 1100miles, should I apply 12% correction and think that my bike has run only 1000 miles instead?

I am curious to know the fuel efficiency. I seem to be getting about 42MPG. But if there is a 12% error in Odometer too, then I am getting only 38MPG!

Any inputs to improve the fuel efficiency is much appreciated!

Thanks in advance,
Sharada
 

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speedos on these bikes are off by about 10% (gps units are not 100% accurate) and odometers are pretty close to spot on.
 

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It's a practice in cars, and especially bikes. These manufacturers bump the speedometer up a teency bit to account for different brands of tires, tire wear, and just general inconsistency (these aren't high end speedometers after all). Dunno if it's safety, or trying to prevent lawsuits from people who get tickets in cars with inaccurate speedos (I've heard of that happening) or what, but every road-legal vehicle I've owned has read a little faster than the GPS, especially motorcycles. Most dealers/mechanics have told me that's done on purpose by the manufacturer.
 

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My GPS and speedo both read the exact same speed. There is only one explanation... I must be a magician!
 

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I believe my odometer is also off just like the speedo. Going by the mile markers on different highways, and in different states my odometer always adds up miles faster. American automobiles tend to have the most accurate speedos, with German the worst, always reading faster. The odometer reading higher is the main reason The Iron Butt Society does not reconize, and even warns, that if you travel 1000 miles according to your odometer, you will most likely fall short of the 1000 mile goal in 24 hours. They match your route to google maps.


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My GPS and speedo both read the exact same speed. There is only one explanation... I must be a magician!
Mine is also pretty much dead on. I think we are lucky.
Can you two tell me the winning lottery numbers cause that just don't happen very often.

Short version of why GPS Speeds are not accurate. (I will refrain from stepping up on the soap box). It all depends on the level of precision (not accuracy) of your GPS unit. Non WAAS (Wide Area Augmentation System) GPS unit are typically around 50 feet. And when it calculates your speed between each position reading you distance could be as far off as 100' (not typical but wost case scenario). With WAAS units you are good up to 25'. Then the worst you could be off between 2 readings is 50'. This is for data that has not been post processed.
 

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I did a little testing on my 2009 Classic. The speedo is off by 10% or so, and the ODO is off too. I drove for exacty 5 miles at different speeds. As soon as my Trip meter hit 5 miles, i stopped. The GPS had a reading of 4.94 miles. Not a lot, but off enough that it will add up.

Going to do a longer test today to see if the results are similar.

I think a speedHealer is in my future!

Doc
 

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Just a thought folks. Thinking particularily about an Odometer that is accurate to within a 0.06 of a mile. If the odometer is perfectly accurate with a new set of OEM tires, properly inflated. I will be off a little bit as the tire rubber wears and in the tire pressure is not to specification. Another thing to remember that Tire Pressure is recommended at two weight ranges. Load is what the load is given the rider and other cargo. It will be somewhere in the range. So even being smack on the PSI may not be smack on for tire deflection. Remember we are talking about being off 6/100's of a mile.
 

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Yeah, but it adds up over time!

I just made the ride into work. 16.9 miles on the ODO, the GPS has it at 16.65 (I stopped the bike right when it went to 16.9). .25 miles, and over 10,000 miles of ridding that will add up.

That's about a 1.5% variance, so over 10K miles that works out to about 150 miles. Now I know it will vary a bit, but since the ODO is tied to the speedo, I wonder if using a speedHealer to fix the speed will also affect the ODO reading.

Anyone have any ideas on that? This weekend on going on a much longer ride, I plan to do the same measurement and see what the differences are.

Doc
 

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I need to check my spedo with a GPS. Not sure mine is off but would like to know.
 

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I have a Vulcan 800 classic. Speedometer reads about 5mph over. I have checked this with local law enforcement speed checking signs. The radar sign read 45 and my speedo says 50


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There's no doubt that both the speedometer and odometers are out on the VN900. The question is by what degree which all depends on many things which move around on a regular basis...tire pressure, worn tires, different tires, pulleys, and the list goes on and on. Even testing with what one deems accurate "testing" devices...GPS, another vehicle Odometer, etc... all have their issues.

Having said that, I am on the verge of converting to OD pulleys, therefore, wanted to know the before vs after changes...speedo and ODO being two of the specs. I timed my ride to GPS and my vehicles. Since the GPS is spot on with my vehicles I deemed it sufficient to gauge the bike. The bike is stock as we speak. As it turns out on my ride, less at the low end then the high end. On the day of testing, in my case it turns out to be 4 - 8%. Therefore speed is off and non linear. I did several runs and the ODO is also off. It turned out to be 2.5km/100km (1.6miles/62miles). It stays pretty consistent at that. I tried highway vs backroards as well. Therefore in my case a full tank can be 12 kms/tank (7.5miles/tank).

For all intense in purposes the ODO intruduces a very small error and no direct relationship to the speedo percentages....the speedo however is another thing.
 

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It's a federal law that speedos can't register less MPH than the actual vehicle speed. I read that years ago in a motorcycle magazine. My head's full of useless information like this. :cool:
 

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It's a federal law that speedos can't register less MPH than the actual vehicle speed. I read that years ago in a motorcycle magazine. My head's full of useless information like this. :cool:
read the same thing in an auto magazine several years ago. Thats why most european cars are of more. With the different tire and wheel options, they can not read slower. Rather than have a calibration for each setup, they use the one that meets these guide lines for all. Since motorcycles dont have the wide range of factory options for different size tires, dont see why they cant be more accurate than 10% off, which mine is, and seems common.
 

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I have owned an '03 Kawi Mean Streak, '05 Nomad, '08 Vulcan 2000, an '07 900 Classic and an '08 900 Custom. I still have the 2000 and both 900s. All of these machines, by roadside digital signs, have read 5 mph optimistic. I put a SpeedoHealer on my 2000 which corrected the mph, according to my buddy's GPS, but the odometer was off: by roadsign signs I traveled .9 of a mile per one mile between sign posts.
 
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