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[Fireguy]

With the speedo reading 70 mph, I'm actually doing 65. Would a dealer be able to correct this? I'd rather not buy a power programmer (TTS) just to fix this.

[Foot Loose]

I've notice much the same, the speedometer reflecting a little higher than actual.  I suppose that's why I don't get tickets doing 70 in a 55 mph zone   
However, as your tire wears, and the diameter is less, that can affect your speedometer. 

[grc]

With the speedo reading 70 mph, I'm actually doing 65. Would a dealer be able to correct this? I'd rather not buy a power programmer (TTS) just to fix this.

I'm fairly certain what the dealership and the MoCo would tell you is that the speedometer is within their tolerances and send you on your way.  Any vehicle speedometer I've ever had experience with tends to read at least slightly high at highway speeds, and they are designed that way on purpose.  Lets say that due to normal variation in manufacturing the accuracy of the speedometer is plus or minus 3 at 60 mph.  Manufacturers will usually skew that to the high side to protect from reading low and contributing to speeding tickets, so rather than +/- 3 mph they will make the tolerance in production something like +5/-1 mph.

It doesn't cost anything to ask your dealership service department if they have a way to reset the calibration of the speedometer.  I'm not sure what they can and cannot do with the Digital Tech system these days.

Jerry

[Steve Cole]

Various country's have different laws. As such there is no one answer good for everyone that's going to read this. In Europe it is required that the speedometer never reads lower than the speed being traveled over the service life of the rear tire so you end up with different speedo setups in different country's. That said the dealership has no way to change the speedometer calibration that I am aware of without using an aftermarket tool to do it with.

[ffltjeff]

I have noticed this as well when riding with my Garmin turned on the speed never matches up.  I asked at the dealership and was told as was said by Jerry they have a +/- of 3 mph and they almost all lean to the high side of the range. 

[Doc 1]

As the tire wears down the closer the speedo reads......when the cords show you're spot on......
Doc

[2010Convertable]

Gosh I never thought of that Doc...

[Rooster]

As the tire wears down the closer the speedo reads......when the cords show you're spot on......
Doc

Or off kaboom

[BigLew55]

I don't buy the tire wear scenario.  I have done the math a few times and new versus old tires would only affect the speedo by approximately 0.25%. 

I think it's just a poor excuse for not putting out a better product.  It's just a number.  Those of us with aTTS or PV know how easy it is to have an accurate speedo , regardless of the tire wear.

[Foot Loose]

I checked my speedo tonight in my garage and it is "perfectly exact spot on". The speedo displayed 0 and the bike was doing 0.   

[Boatman]

 

I think it's just a poor excuse for not putting out a better product.  It's just a number.  Those of us with aTTS or PV know how easy it is to have an accurate speedo , regardless of the tire wear.

I agree with Lew.  In the day of electronics, these speedos should be dead on accurate.  My 05 read fast as well as the 10..

The 2003 Fatboy I had said "certified" on the speedo face and was dead on accurate.   So it can be done by HD, they just choose not to.

[Steve Cole]

Sorry but I disagree with thinking tire wear only is going to give you a 1/4% error over the life of the tire. Calculations are done on tire diameter but it really is done on rotational distance and that varies by the tire size, air pressure and weight on the bike so it's not really that simple and you will see a measurable change over the life of the tire. While I do believe a better job could be done when you figure it all in and then have to live by government rules thing do change.

[Doc 1]

I don't buy the tire wear scenario.  I have done the math a few times and new versus old tires would only affect the speedo by approximately 0.25%. 

I think it's just a poor excuse for not putting out a better product.  It's just a number.  Those of us with aTTS or PV know how easy it is to have an accurate speedo , regardless of the tire wear.

This is why I hate posting on forums anymore......did you notice the little guy laughing at the end of that post....it was a joke....!

[BigLew55]

I don't buy the tire wear scenario.  I have done the math a few times and new versus old tires would only affect the speedo by approximately 0.25%. 

I think it's just a poor excuse for not putting out a better product.  It's just a number.  Those of us with aTTS or PV know how easy it is to have an accurate speedo , regardless of the tire wear.

I do apologize, but it had been a while since I had calculated, and I was a decimal off.  I rechecked this morning.  It was just over 2%.  This would account for about 1.5 MPH at 75.

It is still not close to the ~7% that every one of my last 5 (since I've owned GPS) Touring bikes has been off, while every one of my last 5 domestic cages has been within 1 mph at 75mph.

[ultrarider123]

This is why I hate posting on forums anymore......did you notice the little guy laughing at the end of that post....it was a joke....!

I laughed, Doc....

And yes, my speedo is off as well (running 75, it's actually closer to 69-70).  All Police bikes that HD (or other manufacturers) make have certified, calibrated speedometers.  They say so on the face of the speedo.  I'm sure there is a reason they don't install these on their "normal" scooters but you'd-a thunk they might consider installation of a calibrated speedo on a CVO......