Speedo accuracy

[Motowalt]

Excuse my ignorance but my s10 is 4mph out at 30mph 4mph @40 and 5-6 at higher speeds according to Zumo 660..
I would always expect a little out on most machines. My last bike K1300GT was fairly accurate around 2 mph at almost all speeds. Again according to Zumo. What is a Speed Healer?

I've used the speedo healer on several of my bikes over the years...I like to know exactly what speed I am going at a glance without having to look for the speed on the GPS...which I don't always have installed...

It also corrects for odometer error, which can be substantial if you ride alot and will decrease the value of your bike when it's time to sell it...

http://www.healtech-electronics.com/

 

[stevepsd]

It also corrects for odometer error, which can be substantial if you ride alot and will decrease the value of your bike when it's time to sell it...

http://www.healtech-electronics.com/

Just to be clear.....on the ST, the odometer is pretty darn close to true but the speed reads high (mine is around 7% fast). If you use the speedo healer to correct the speedometer display then your odometer will read low by the same amount.

Why is this? Unlike the old mechinical speedos where the speedometer/odometer were mechanically linked, most of these newer electronic speedos have a built-it bias to make the speedo read fast compared to the odometer and you cannot adjust one without affecting the other. Very frustrating.

 

[Kevhunts]

These folks have a recalibration device in the works for the S10.

http://www.12oclocklabs.com/

 

[markjenn]

Just to be clear.....on the ST, the odometer is pretty darn close to true but the speed reads high (mine is around 7% fast). If you use the speedo healer to correct the speedometer display then your odometer will read low by the same amount.

Why is this? Unlike the old mechinical speedos where the speedometer/odometer were mechanically linked, most of these newer electronic speedos have a built-it bias to make the speedo read fast compared to the odometer and you cannot adjust one without affecting the other. Very frustrating.

Yes, just to amplify a bit.... although the speedo and odometer work off the same distance measurement sensor (and therefore should be consistent with one another since speed is simply distance divided by time), they are not - there is a deliberate design bias built into the system to have the odometer be accurate and the speedo to be 6-8% high. The CW is that this bias is driven by regulatory agencies in the different markets the bike is sold which specify an error tolerance for each, but require the error tolerance for the odometer to be centered around zero error (e.g., +/- 2%), while the speedo tolerance must be centered around a higher reading so there is no possibility they ever read low (e.g., -0%, +10%).

This means a speedo-healer-type solution that changes the speed sensor cannot correct both the odometer and speedo - if you make one accurate, the other will be off. (It may not be a terrible thing for the odometer to read low, obviously).

I don't know how the S10 is setup, but if the speed sensor is the same one used for the ABS and traction control, I'd be hesitant to do anything with these systems.

A small bicycle speedometer is another possible solution. I've run some of the small Sigma Sports on a variety of motorcycles over the years and they're reasonably easy to setup and accept a sufficient range of wheel circumferences that you can get them dialed in very exactly. And unlike many bicycle speedos, they have a very high upper limit of speeds they'll show - I think above 150 mph for most models.

- Mark

 

[Motowalt]

These folks have a recalibration device in the works for the S10.

http://www.12oclocklabs.com/

Thanks for that link Kev...

That company builds turn signal running light adapters that look interesting also...may get those for my front LED's...

 

[Tall Paul]

In Motorcycle Consumer News' reveiw of the Super 10 it noted Speed @ 65 mph indicated was 60.9 mph.
Paul

 

[djm_ct]

After finally getting my RAM GPS mount installed and testing this weekend, I'm finding the the speedo is off by the following:

Speedo GPS (actual) Amt of error
50 46 4
60 55 5
70 64 6

This works out to an average of about 9% over the actual. That's a lot and I don't like it, but after reading other posts it seems to be the norm, or close to it.
And there doesn't seem to be much you can do about it without throwing off the odometer, which I like even less.

I haven't checked the odometer against the GPS. I'm going to do that after work today. Most folks are reporting that the odometer is usually pretty accurate,
or at least only off by a percent or two. I'll update my post after I check mine.

Bottom line. It is what it is. If you can't live with it, mount a gps and use it's speedo, or, just know the amount of error and do the math in your head. If you just
subtract 5 from the speedo reading at most driving speeds, you'll be pretty close.

 

[RidingUpandDown]

w/ Garmin ZUMO for crosscheck - For the 1st 8k miles on BSBW tires it was consistently 10% off at any given speed; 4 at 40, 5 at 50...
Now w/ new/different Heide tires it is consistently right at only 4-5 mph off at any speed. ::021::

d ::001::

 

[imrubicon]

I worry more about if I took the trash out LOL
Wait until you guys double check your cars ::010::
If you look real close in the bright sun you can see different shades in the paint as well !

::021::

 

[3putt]

I installed the SpeedDRD pretty early on (12,000 miles ago) and after testing it with the GPS, settled on 6.1%. Several of us tested last year and found that the speedo was about 7% off and the odometer was about 2% off. So after adjusting to 6.1% the odometer is now 4% short which makes your mpg look worse than stock.

The install thread has pictures, but you must cut the blue wire, no plug and go.

 

[wuzfast]

Just recently did a 4K mile ride, Ohio to Austin to S.C. and home....my speedo/odo are off by 9.5 o/o.....called Yamaha just for giggles to see what they say....the official line was "10 percent or less was acceptable error".....about what I expected.....all the manufacturers must go to the same seminar....couple of Beemers ago BMW told me a half a quart of oil in 5k miles was "acceptable consumption"...

 

[avc8130]

Just recently did a 4K mile ride, Ohio to Austin to S.C. and home....my speedo/odo are off by 9.5 o/o.....called Yamaha just for giggles to see what they say....the official line was "10 percent or less was acceptable error".....about what I expected.....all the manufacturers must go to the same seminar....couple of Beemers ago BMW told me a half a quart of oil in 5k miles was "acceptable consumption"...

Are you SURE they are both off the same amount?

I thought they were also after my trip to TX from NJ, but I did a recent experiment.

I rode 338 miles on Friday according to my odo last Friday. My Tracks on my Android showed 328 miles traveled.

That's ~3% error on the odo.

I have no idea what is "truth".

PS: most auto manufacturers say 1 quart per 1k miles is considered acceptable oil consumption...

ac

 

[Zuan]

I have recalibrated my speedometer with a Speedohealer. It requred an 8% correction. That made my odometer 5% light. I can live with an odometer which understates my accumulated mileage. And I feel much better knowing that my speed reading is accurate even though I always have a gps mounted.

John

 

[markjenn]

While a GPS can be a good check for steady-state speedo error, it doesn't do nearly as well as an odometer accuracy check due to the way it manages position jitter and averaging. I'm still pending to get mine on the interstate and use the mile markers to calibrate.

- Mark

 

[jaeger22]

While a GPS can be a good check for steady-state speedo error, it doesn't do nearly as well as an odometer accuracy check due to the way it manages position jitter and averaging. I'm still pending to get mine on the interstate and use the mile markers to calibrate.

Yes this is correct. It only knows instantaneous position (with some error) and extrapolates distance between samples. It has to assume a straight line in between. The position error will average out but the extra travel between points is lost. However, I have found that it is VERY accurate if you are traveling in a straight line.
I just got back from a 2,600 mile run that was mostly interstate and it was boring but provided the perfect opportunity to do the definitive speedometer and odometer accurate study.
The speedo was simple, I took it to 120 indicated and it read 110 GPS. There is some inaccuracy because both the speedo and the GPS read out in even MPH, no decimal points, but that is minimized at the highest speed. So I calculate for my bike at least, the speedo reads about 9% higher than true, or to look at it the other way, true is 8.3% less than what the speedo reads.
The odometer took a bit more work. I wasn't sure at the start how accurate the interstate mile markers are or the GPS. So I compared both of them and the odometer. I did 4 separate 100 mile runs on straight sections of interstate in two states. I was surprised at how close the GPS and mile markers matched. On straight interstate they matched within a few tenths over 100 miles! ???. If less straight, the GPS fell a bit more behind, but not as much as I expected. So I concluded the mile markers are very accurate over long intervals. So how did it come out?
All 4 readings were very close and averaged 103.4 miles for the actual 100 miles, or 3.4% high.
As always, YMMV (Pun intended )
John