Speedometer Error?

My Triumph Sprint is generally optimistic by 10% according to many sources that compared GPS versus speedo. My new (to me) 2001 DRZ-S is back in one piece and running as of last night. What is the accuracy of the DRZ speedometer like? I don't have a GPS to compare against.

Mine, according to GPS, indicates fast...70 mph indicated = 61 mph GPS. 35 mph indicated = 28 mph GP. The faster you go the worse it gets. Pretty typical I think. Should save you some in-town tickets while preserving your ego. :naughty:

I have done an "official" check yet, but, my impression is that it is about 10mph optimistic. I have paced cars and tried to look in the window at thie speedo. Mine says 60 when thiers says about 52 or so. I'm sure it is much worse as you go faster. Most american motorists have no concept of speed :naughty: , and most go over the posted limits as a general rule. :D However when I ride even 10 mph over the limit, I'm usually getting run over. :naughty:

I measured my speedometer accuracy with a GPS and determined that the indicated reading was consistently 12 percent too high.

Actual Indicated

0 0

15 17

30 34

45 50

60 67

75 84

90 101

I'm right on 10% off according to my 60CS GPS. I'd think they're all off the same calibration, but the actual readings vary by tire type.

I would like to calibrate my speedometer....

Does adjusting the "Correction Coefficient" of the Trip Meter also adjust the speedometer?

It should, but I haven't tried it yet..

As per the Manual:

Press Mode-Trip

Hold Set-Time/Trip for 2 Seconds

Press Adjust + Button or Adjust - Button to adjust correction coefficient for Trip A/B

Press Set-Time/Trip again to exit.

Can be adjusted from 70% to 130%

I measured my speedometer accuracy with a GPS and determined that the indicated reading was consistently 12 percent too high.

Actual Indicated

0 0

15 17

30 34

45 50

60 67

75 84

90 101

Thus the speedometer is tied to the odometer so all drz's with stock computer indicate 12% more mileage. That would also decrease the actual fuel effeciency also?

HH

If 12% too high is consistent across bikes, then it's pretty easy to estimate your actual speed. Just subtract the "tens" digit from the indicated speed. For example, you note that 67 indicated is 60 actual. Subtract 6 (the tens digit in 67) from 67 and you get 61. Close enough for me.

My Triumph is 10% optimistic on speed, but right on for odometer (probably a law). It wouldn't surprise me if the DRZ was similar. I think the calibration stuff must be to handle different model tires (different circumferences).

I'm going to set mine at 112% and see what happens - I know it sounds smooth NOW at 70, But since day one - 75 MPH - it sounds like a Sewing Machine, but all noise and vibration goes away at 80. I think it harmonizes or some big word :naughty:

If the speedo is off by 10 mph, then it should sound like a sewing machine at 65 or 70???

We'll see - going out with my Brother on his R1 today for a good ride up the coast.

I would like to calibrate my speedometer....

Does adjusting the "Correction Coefficient" of the Trip Meter also adjust the speedometer?

No, it only adjusts the trip meter. I tried with my SM wheels, which make the speedo close to 20% off.

I'll second that - Speedometer stays the same - Odometer shows more mileage..

Haven't paced a car yet to find out if its off, but if it is - how do you fix it?

The German TUV has a spec saying that the speedos have to never be slow no matter what tire you put on a vehicle. That makes mfgs calibrate these as fast and also prevents them from putting in a way for users to re-calibrate them. While the entire world isn't Germany, I think all mfgs follow suit. This way nobody can sue them for getting a ticket because the speedo said 60 & it really was going 65.

Look at the wide variety of tires we can put on the DRZ & how they wear too. If Zuke didn't calibrate this about 10% high, somebody would bitch that they got that ticket.

That German thing actually makes sence to what I figured out, if anyone knows different, please let me know.

I have a 2004 S. With the stock tires on it, the speedo was 8% fast but the odometer was exact according to the GPS. I put off road tires on it which were a little bigger and now the speedo is 7% fast but the odometer is 1% under reading distance according to the GPS. I put the correction to 94% which affects the trips A and B only and does not affect the odometer or the speedometer.

I could never figure out why the company would make the odometer not match the speedometer but if the German rule is correct then it makes sence they would make the odometer as accuratly as possible as there is no rule against it but it would be better if they made the speedo accurate for the countries other than Germany.

On the other hand, if they at least made the speedo and odometer match maybe an after market company would make a different gear so it could be adjusted to be accurate.

Opps. What I meant to say about the 94% was that was how I fugured the trip was not off. When I put it to 94% it put it off. I put it to 101% with the new tires and it was perfect, which meant if I had left it at 100% with the stock tires it would also have been perfect.

Grungy

Thus the speedometer is tied to the odometer so all drz's with stock computer indicate 12% more mileage. That would also decrease the actual fuel effeciency also?

My experience with a Suzuki Bandit 1200S and a Sigma bicycle computer is that while the speedo was off 10%, the odometer was dead on. The speedo and odo may be getting the same signal from the wheel, but they're using different calibrations to get their results.

Indeed, the easiest way to calibrate the Sigma was to just fiddle the numbers until the odometers matched. The Sigma then gave a true speed.

Need someone to manufacture an after market GPS based speedometer, they have them for cars and boats and airplanes then your tires wont matter a bit and accuracy will be great.

Just about any of the GPS out there will work for that purpose. I considered doing it myself.

I have an '07 SM. I bought it from the previous owner who had Supermoto tires/wheels and a set of larger wheels with pretty aggressive knobby tires. I chose the off road wheels/tires. My wife has a stock Kawi Super Sherpa. When she is doing 50 mph, my speedo indicates 41. When she does 55, my speedo indicates 44. I assume it gets even more out of whack as speed increases. Also, the trip meter is off. After a long ride, hers says 68 or so, mine indicates 59. When I'm trying to stay within the speed limit, I just tack on 6-8 mph to what is indicated. Kind of a pain.

If you can look at the speedo, then you aren't going fast enough!

I found a small GPS based 12V speedo for 130 on amazon.. Tempting!

Edited by crzyatv

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