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Discussion Starter · #1 ·
Just wondering if anyone has done any testing as to the accuracy of the speedo? Either via GPS or buddy? I know on my 03 Vol there was a 10% variance - when it read 50, you were really doing 45... at 80, you were really at 72... etc.

Yesterday I hit 120 but it didn't "feel" like 120... more like 105'ish. Also when cruising at what shows as 80, I'm not really passing folks as I would in the truck at 80 - am I really doing 72?

Just thinking the 10% variance might exist with the 109, too.

J
 
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If they are like every other Suzuki I've owned 10% variance sounds about right. I haven't put the GPS mount on it yet so I haven't had a chance to check it out but I agree, at 75 or 80 I'm just keeping up with traffic.
 

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I have noticed the same thing I was waiting for the police to set up those radar carts on the side of the road to check it. My old C50 was about 10% off as well.
 

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I have mounted a GPS on mine and the first thing I did was test the speedo. (Pics are in another thread).

It was nearly exactly 8% off. I have owned two other late-model Suzis, and they were also 8% off. I expect that this figure is probably pretty consistent across the Boulevard line.

So, if you were doing 120 indicated, you were probably around 110 actual...
 

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I believe thats the lawyers padding there...
If there was any chance it showed lower than actual someone would hold Suzuki accountable for their speeding tickets or something.

SledZep
 

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sledzep01 said:
I believe thats the lawyers padding there...
Yes, this is why it's done. All manufacturers do it, though the variance is a bit different from brand to brand.
 

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Actually i have an article somewhere on why they read incorectly. Its not about them doing it on purpose, its physics. You'll notice actually that the margin of error increases w/ speed. Article explains it a lot better i'll get on finding it.
 

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ns2973 said:
You'll notice actually that the margin of error increases w/ speed.Â
Um, this is kind of obvious, isn't it? If it is a given percentage off, then of course, the actual margin increases with speed. If it were a flat amount, the speedo would show you going 8 mph at a stoplight. ;)
 
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This brings up another interesting question. Doesn't this give you false odometer readings and in turn false fuel mileage estimates? ;)
 

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gradona said:
This brings up another interesting question. Doesn't this give you false odometer readings and in turn false fuel mileage estimates? ;)
No, the odometer is accurate. The bike actually "knows" it's true speed. They just calibrate the speedos to read low.

(When I say "accurate", I'm talking agreement with GPS readings +/- 0.5 miles over the course of a 300 mile trip )
 

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Joshua_109 said:
So why don't they just calibrate it correctly? Seems kind of stupid to me to buy a $12000 INCORRECT speedometer! ?? Anyone?
If you buy a $35,000 fully decked out Screamin' Eagle Ultra Glide, you'll find the same thing. Nothing to do with the price. Nothing to do with a lack of quality control. This is by design. ALL companies do it.

In many European countries, it is the LAW that bike sppedos must be calibrated to read low.
 

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I had my state trooper buddy run lazer on me when I first got it. We went from 50 all the way up to 95 and it was off 5 mph at every speed we tested. It was kinda fun running 95 past a trooper and not get a ticket :cop: :clap2:
 

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I think it is their design...it's naturally flawed. I had a 2004 Aprilia RSV1000R and it was dead on at over 100 mph...gps verified. I believe their sensor was on the back wheel near the rear brake. The Suzukis that I have owned in the past...about 5 different bikes, had the sensor at the front sprocket. Needless to say, when you changed teeth on either sprocket, it affected the speedo....so I think Suzukis error is based upon trying to get the speedo matched as close as they could to the front sprocket. Not really sure, just a speculation on my part.
 
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