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Hi guys,

So I recently got a GPS unit and it constantly tells me I'm doing 10mph lower than my speedometer is telling me. It makes sense because according to my speedometer I'm typically doing between 70-90 and I've never been pulled over in over a month of driving on the expressway (and I'm only usually going a little faster than the cars around me).

I asked a friend who also has a Duc and he says that all Ducs "overshoot" the speedometer by about 8% for safety. I guess it does sound smart to keep motorcyclist driving slower than they think. What say you?
 

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On a very long and boring ride, I once reset my trip meter (on a 748 Ducati) and watched the mile markers. Found it interesting that I would travel .9 miles for every 1 mile between mile markers. So for every 1000 miles recorded on the speedo, you actually did 1100. Once you get to 15,000 on the speedo, you actually have missed an entire oil service ( if you do it every 1500 miles like I do) without even knowing it!!!
 

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In the 696 and 1100 manuals it specifically states that the computer increases the input speed read from the wheel speed sensor by 8% before displaying it on the dash.

As I've brought up in other threads, this is due to European speedometer requirements. They're required to read high and Ducati simply makes them read right in the middle of the ~1%-16% range that they're allowed to read at typically legal highway speeds.

Please note that this applies to the speedometer only. The computer does not increase the reading for the odometer.
 

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Please note that this applies to the speedometer only. The computer does not increase the reading for the odometer.
I have a hard time believing the speedometer and odometer are independent in relation to their calculations.

Do you have any proof of this?
 

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I have a hard time believing the speedometer and odometer are independent in relation to their calculations.

Do you have any proof of this?
Yes. The manual and European regulations.

Why is that hard to believe? The odometer is require to be quite accurate, and the speedometer is required to read high. It's all fed into the computer from the sensor, and the computer decides what to display where. Why's it hard to believe that a computer can perform calculations?
 

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I, too thought this was odd, but sure enough... true. It's in the manual. And apparently, quite a few motorcycle brands operate this way. So yeah, that 137mph you thought you saw was only 126mph. Much safer speed. ;)
 

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Very interesting thread. While rolling up I-77 this past weekend ('06 S2R) through West Virginia, there are countless construction sections where they are doing maintenance on bridges. At each of these work sites is a DOT radar station to remind you to keep your speed in check. Every one of these was dead on with my speedo reading. 65 on my speedo displayed as 65 on the radar screen. Looks like mine might be a "broke" by actually being correct. I'm going to check my odometer between mile markers on the way home tonight.
 

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As I've posted before:


More on speedometer accuracy...

European Union Directive 2000/7/EC set the requirements for speedometer accuracy.

There are two main requirements when tested:
1. That indicated speed is never below actual speed.
2. That indicated speed is never above 110%+4 km/h of actual speed.

For actual production motorcycles and motor tricycles, the upper limit increases to 110%+8 km/h (but remains 110%+4 km/h for mopeds).

So for a production motorcycle rolling at an actual 80 MPH, the indicated speed can't be below 80 MPH, and can't be above 92.97 MPH.

As this upper limit is 16.2% higher than actual, a built-in 8% error puts the Ducati motorcycle firmly in the middle of the legal range at highway speeds.

Link: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32000L0007:EN:NOT
 
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