The Real Deal on Speedo Accuracy (Should say INaccuracy)

[Rick M]

GPS does make mistakes

Don't bet the farm on your GPS...I run a radar unit and a Garmin Map76CS on my sled....and unless you believe my sled does 271KPH (162.6MPH)....GPS s make mistakes.



Rick

 

[LazyBastard]

My GPS shows a maximum of 150.0 kph.

 

[Sled Dog]

Then you would be going faster than what the speedo reads. I would think!

 

[LazyBastard]

Who me?

Nah. My GPS shows 150 kph when the pod says 100 mph (160 kph),.... my GPS shows 150 kph when the pod says 110 mph (176 kph), ... my GPS shows 150 kph when the pod says 135 mph (216 kph) --- YEAH RIGHT!! LOL.

 

[Snowman269]

ROTFLMAO!!!! I'm still laughing over the "Doctor Bastard" remark! OMG is that friggin funny!!!!! HAHAHAHAHAHAHHAHAHAHAHAAAAAA!!!
dOCTOR, hahahahahahahahahahah!

halfway asleep, is that 50% asleep!!!!! 50% AWAKE! nAH, IT'S BOTH! HAHAHAHHAHAHAHAHAHAHAAAAAAAAAAA!!!! jUST CHECKING, dOCTOR!!!!!


sNOWMAN

i DID THE CAPSLOCK, JUST 4 U.

 

[Sled Dog]

Who me?

Nah. My GPS shows 150 kph when the pod says 100 mph (160 kph),.... my GPS shows 150 kph when the pod says 110 mph (176 kph), ... my GPS shows 150 kph when the pod says 135 mph (216 kph) --- YEAH RIGHT!! LOL.

On ice and the lugs are not letting the track touch the surface in essence making your track cover more ground per revolution. Same as putting bigger tires on your truck. The speedometer is out and you would be going faster than what the speedometer read. In Yamaha's case it might be accurate for a change. lol

 

[nhrxrider]

That 3% is the AVERAGE that its off. Its very close at lower speeds (probably off only 1%) but the few times you jump up over 90 or 100, you'll be off by more than 3%. At least this is my observation while comparing my speedo to my GPS. Its very close at low speeds, and off more at high speeds. The odometer is giving you the average. I bet if you did 100 miles at a constant 30 mph, your odometer would be just about dead on...but do the same 100 miles without dropping below 100 mph, and I bet the odometer will be off as much as the speedometer (probably reading 120+ miles for that 100 miles travelled).

Instead, you are looking at the odometer average. If you could somehow average the speedometer error over the entire distance you travelled, I'm sure it would be the same 3% your odometer is off.

It would take some extra work on Yamaha's part to program the gauge assembly to read correctly at lower speeds but read high at high speeds. And for what its worth, almost every sled I ever rode was off at the top end. My ZRT800 (mildly modded with PSI pipes, reeds, DG silencer, a good clutch kit, and overbored carbs) used to get up to an indicated 130+ on the speedometer. I didn't have the GPS back in those days, or a radar gun, but I'm sure it wasn't hitting those speeds. A couple weeks ago during my first ride of the season, my friend (MXZ700 with 136" Ripsaw) and I were on a lake covered with packed snow. I was reading about 98 when I was going by him, but he was reading well over 100.

Jim

 

[QCRider]

That 3% is the AVERAGE that its off. Its very close at lower speeds (probably off only 1%) but the few times you jump up over 90 or 100, you'll be off by more than 3%. At least this is my observation while comparing my speedo to my GPS. Its very close at low speeds, and off more at high speeds. The odometer is giving you the average. I bet if you did 100 miles at a constant 30 mph, your odometer would be just about dead on...but do the same 100 miles without dropping below 100 mph, and I bet the odometer will be off as much as the speedometer (probably reading 120+ miles for that 100 miles travelled).

Instead, you are looking at the odometer average. If you could somehow average the speedometer error over the entire distance you travelled, I'm sure it would be the same 3% your odometer is off.

It would take some extra work on Yamaha's part to program the gauge assembly to read correctly at lower speeds but read high at high speeds. And for what its worth, almost every sled I ever rode was off at the top end. My ZRT800 (mildly modded with PSI pipes, reeds, DG silencer, a good clutch kit, and overbored carbs) used to get up to an indicated 130+ on the speedometer. I didn't have the GPS back in those days, or a radar gun, but I'm sure it wasn't hitting those speeds. A couple weeks ago during my first ride of the season, my friend (MXZ700 with 136" Ripsaw) and I were on a lake covered with packed snow. I was reading about 98 when I was going by him, but he was reading well over 100.

Jim

Jim;

The speed is incorrect at ANY indicated speed. Not just high speeds. It's just as wrong at 30 as it is at 100. And for those that doubt the accuracy of the GPS, it is DEAD ON with my Expedition's Speedometer as well as my Dad's Chevy Truck Speedometer. The odometer is accurate. The only way your theory of averages would work is if the speedo was ever accurate, and it is not. Not at any speed. The difference is obviously intentional, and if you notice, I said that the Ski Doo was exactly the same. It seems to be common practice. Why does this seem so impossible to you guys?

 

[banjo04414]

Buckeye hit it on the head. If you want a close reading do the speedo mod. Seems to be within a few miles of actual radar readings.

 

[QCRider]

You guys are missing the point of the whole thing. We all knew it was wrong. What this proves is that it is INTENTIONALLY wrong. Otherwise the odometer would be wrong too.

 

[LazyBastard]

it is DEAD ON with my Expedition's Speedometer as well as my Dad's Chevy Truck Speedometer.

Funny you should say that, 'cause Chevy reads higher than the gun.

 

[Anonymous]

You guys are missing the point of the whole thing. We all knew it was wrong. What this proves is that it is INTENTIONALLY wrong. Otherwise the odometer would be wrong too.

This whole thread is starting to get a little long and some what annoying.... The inaccuracy of the speedometer and the accuracy of the odometer has allready been discussed..... Your points prove no intentionally wrong doing on the part of Yamaha......Just that the speedometer is off and the odometer is correct.... Now if you can make both the speedometer and odometer show accurate numbers than by all means go right a head and prove it can be done.....You would then have proof that Yamaha could do it as well and is intentionally not .... Other than that step back and take a breather.....

 

[LazyBastard]

If you want to make it accurate, you need sensors rather than spin-counters.

 

[welterracer]

You guys are missing the point of the whole thing. We all knew it was wrong. What this proves is that it is INTENTIONALLY wrong. Otherwise the odometer would be wrong too.

This whole thread is starting to get a little long and some what annoying.... The inaccuracy of the speedometer and the accuracy of the odometer has allready been discussed..... Your points prove no intentionally wrong doing on the part of Yamaha......Just that the speedometer is off and the odometer is correct.... Now if you can make both the speedometer and odometer show accurate numbers than by all means go right a head and prove it can be done.....You would then have proof that Yamaha could do it as well and is intentionally not .... Other than that step back and take a breather.....

AMEN....

Yamahas odometer is as close as any of the other big 3s sleds.. Its the speedos that are off!!

THERE ..

DONE...

ITS OVER...

GIVE IT UP!!

 

[QCRider]

Yamahas odometer is as close as any of the other big 3s sleds.. Its the speedos that are off!!

THERE ..

DONE...

ITS OVER...

GIVE IT UP!!

Which by it's very nature means that if the odometer is accurate and the speedo ISN'T, and they take their input from the same place, something has been done to make the speedo read high. Get it?