I read a few threads about speedo error on newer bikes so I have been riding around 5 over in town and 10 over on the highway and not worrying about it. Today I took my GPS with me to check my speedo. Well it's only off by 2 mph through the 0-80 range. 28@30, 58@60 and 78@80. Not bad. I was wondering why I was passing so many cars on I-94 going to work.

 

I have construction in my neighborhood. They have speed indicators in all the work zones. I have been consistently 4 mph faster than the indicated speed. I guess this thread explains it. I didn't know there was a speedo issue. My ride is a '12 RKC

 

lots of folks are off by just a little. mine, when i go 65 on the spedo is reading 61or so on the gps. makes you reach your mileage warranty a lot sooner. i asked if they can adjust them and my service guys just said nope. i think its all a plot by harley :-).

 

Well, no speedo is perfect, but some are way off. My old softail was dead on, but ALL my past BMW's were way off. Around 7 under indicated @ 70.

 

Anytime that I have passed those small radar trailers near construction sites and other areas all of my HD's have been spot on.

In Cycle Guide magazine when they do a report on a Harley the data always includes a speedometer correction for 30 mph and 60 mph. Every one that they tested was spot on at 30 and 60. Not so with the other makes.

When I check with GPS I get the same info.

It appears that HD speedometers are more accurate than others not less accurate.

 

My bike's speedo indicates I am going 2mph faster than my GPS says I am going. If speedo says 70, GPS says 68. This is true at all speeds as far as I know.

 

Glad this topic was brought up. On my 09 SG i was constantly showing the speedo 3-5 mph slower than the GPS. Have new RG and haven't figured out how to mount the GPS so no info on that. Always wondered what was more accurate. Is it true the GPS is def more accurate?

 

Found out during my Iron Butt Bunburner Gold that my 12' FLHTK is 3 to 4 mph off ( gauge read 81 and GPS read 77 ). This made my total milege off by 50 miles. Not what you want to find out when your needing every mile count towards the IronButt! FT

 

GPS should be more accurate than speedo. I notice about a 2 mph difference at highway speeds (speedo higher).

Wouldn't trust the stationary radar units on the side of the road as a calibration. They aren't accurate or regularly checked. They are just a deterrent and not meant to be a true measure for enforcement.

Thought I saw someone post something saying that they used their PV1 to adjust their speedo. May have just been imagining or misread, but wondering how that would work? Not sure I see how... Anyone know what they were talking about?

 

Some tuners will allow you to calibrate your speedometer, I know the TTS Mastertune does.