digital speedo is off
#1
07-27-2018, 08:59 AM
digital speedo is off
I put a combination analog tach / digital speedo on my bike a while back. Last weekend I did 500 miles on the interstate, and during this ride I had my GPS on and noticed that not only is my speedometer widly wrong, but the odometer is recording bad information too. This is something I'm going to have to solve because I need my trip meter to be accurate. Any idea what could be causing this? For background, this is a 2009 XL883L with a Hammer 1275 and Power Vision, with stock final drive gear. I don't know if it's always been wrong, or if it's new, or if it went to hell when I did the 1275 upgrade or what.
#2
07-27-2018, 09:03 AM
The 1275 upgrade should not have affected the speedometer unless you changed your sprockets which you said you have not. The speedo marries itself to the ECM. Are you certain your original speedo was accurate? Did you have a chance to check the original for accuracy? I have the combo digital speedo analog tach and it seems to be pretty accurate according to the radar signs that disclose your speed put by the city.
#3
07-27-2018, 09:06 AM
The 1275 upgrade should not have affected the speedometer unless you changed your sprockets which you said you have not. The speedo marries itself to the ECM. Are you certain your original speedo was accurate? Did you have a chance to check the original for accuracy? I have the combo digital speedo analog tach and it seems to be pretty accurate according to the radar signs that disclose your speed put by the city.
#4
07-27-2018, 09:12 AM
to the original poster: you have a powervision? You can adjust the speedo with powervision-
Go into WinPV, under the Setup>Options menu, make sure the 'User Level' is set to 'Pro''
Open up your tune (*.pvt file). Under the 'Gear' folder you'll find the 'Speedometer Calibration' table. This table has only one value, that being 'PPU'. Adjust this value slightly one way or the other until your speedo matches your GPS.
#5
07-27-2018, 09:15 AM
Club Member
This subject comes up often around HDF! A vehicle speedo cannot be as accurate as a gps for several reasons. Manufacturers are required (by law in some countries) to ensure their speedo is optimistic, in other words it never reads slower than the vehicle is actually travelling. Your tyres will wear over time, with their OD getting smaller and the speedo cannot compensate for that like a gps can. There are several components involved in providing info to the speedo and each of them has potential for inaccuracy.
#6
07-27-2018, 09:40 AM
Mine as well. Dead on, actually.
to the original poster: you have a powervision? You can adjust the speedo with powervision-
Go into WinPV, under the Setup>Options menu, make sure the 'User Level' is set to 'Pro''
Open up your tune (*.pvt file). Under the 'Gear' folder you'll find the 'Speedometer Calibration' table. This table has only one value, that being 'PPU'. Adjust this value slightly one way or the other until your speedo matches your GPS.
to the original poster: you have a powervision? You can adjust the speedo with powervision-
Go into WinPV, under the Setup>Options menu, make sure the 'User Level' is set to 'Pro''
Open up your tune (*.pvt file). Under the 'Gear' folder you'll find the 'Speedometer Calibration' table. This table has only one value, that being 'PPU'. Adjust this value slightly one way or the other until your speedo matches your GPS.
This subject comes up often around HDF! A vehicle speedo cannot be as accurate as a gps for several reasons. Manufacturers are required (by law in some countries) to ensure their speedo is optimistic, in other words it never reads slower than the vehicle is actually travelling. Your tyres will wear over time, with their OD getting smaller and the speedo cannot compensate for that like a gps can. There are several components involved in providing info to the speedo and each of them has potential for inaccuracy.
#7
07-27-2018, 09:54 AM
Club Member
You're wrong to think that! Unlike a gps unit, a vehicle has several sources of error, which can accumulate. To start with your speedo possibly reads 10mph before you start moving, although it should get better after that. If it reads 10mph out at 100mph that is not bad! It will be interesting to see if you can improve accuracy through your PV.
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#8
07-27-2018, 10:45 AM
As said above, it can be corrected with your PV.
The following 2 users liked this post by cHarley:
1HD4CJM1X4K (08-07-2018),
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#10
07-27-2018, 10:53 AM
Cruiser
There are several ways to check the accuracy of your Odometer.
Even if your Odometer were spot on, this would not necessarily mean your Speedometer is accurate.
GPS measures speed no matter if you are going in a circle or up a hill, but whether you are going up and down a mountainside or traveling on a straight, flat road, all that matters is what speed and distance your vehicle is moving. Checking your distance traveled by using mile markers is one way to check the accuracy. This should be a good guideline if you stay in your lane and do not weave. One mile marker will not prove accuracy, but averaging 10 consecutive mile markers will improve your observation.
You have quite a few options.
Mile Markers, GPS, Using an APP on your phone, Radar units.
The radar units you find placed on the roadside are not 100 percent because they are turned towards the lane at an angle instead of being aligned in the middle of the lane you are traveling in.
So how close is close enough.
If your speedo/odometer is basically consistent, all you need to do is convert your numbers. In other words, if you KNOW you are off by ten percent, then add or subtract 10% and you are golden. If you need to document your miles by the odometer, then you will need to calibrate.
GPS measures speed no matter if you are going in a circle or up a hill, but whether you are going up and down a mountainside or traveling on a straight, flat road, all that matters is what speed and distance your vehicle is moving. Checking your distance traveled by using mile markers is one way to check the accuracy. This should be a good guideline if you stay in your lane and do not weave. One mile marker will not prove accuracy, but averaging 10 consecutive mile markers will improve your observation.
You have quite a few options.
Mile Markers, GPS, Using an APP on your phone, Radar units.
The radar units you find placed on the roadside are not 100 percent because they are turned towards the lane at an angle instead of being aligned in the middle of the lane you are traveling in.
So how close is close enough.
If your speedo/odometer is basically consistent, all you need to do is convert your numbers. In other words, if you KNOW you are off by ten percent, then add or subtract 10% and you are golden. If you need to document your miles by the odometer, then you will need to calibrate.
Last edited by 1HD4CJM1X4K; 07-27-2018 at 01:18 PM.