V85 Speedometer inaccuracy

[Huzo]

I think your mate Theodore Roosevelt put it best..

[elvisboy77]

Not in bloody Australia you wouldn’t..
Speed cameras get you for 3 k over @ $200 a pop.

Then ride 5 kph under the posted limit.  Problem solved.

[Huzo]

Then ride 5 kph under the posted limit.  Problem solved.

I remember you Elvisboy..!
You’re the bloke who used to “worry” about the accuracy of your speedo, but now you don’t.
I’m not “worried” about mine, I just want the bastard to be within what I think is ok. If you’ve taught yourself to accept mediocrity, then I should learn from your preachings, I’m starting to see your point actually..
“If something doesn’t come up to your expectation..?
SIMPLES..!
Just lower your expectation....”
I don’t understand some of you guys..(or maybe I do..)
If the tank on your bike was mounted crookedly, you’d want it fixed
If it pops and farts on overrun too much for you, you’d want it fixed
If she’s not up to scratch for your bucket list trip, you’d want it fixed
And so on..
I’ve seen interminable examples of blokes here who buggerise around shaving microns off their windscreens or adding contraptions to minimise wind buffeting, then in a burst of enlightenment throw some gargantuan piece of crap on the front and swagger around waving their Bibles above their head as if they’ve delivered us all to the Promised Land...!
Jesus H spare me..!
But it’s just one example of what someone tries to do to improve their lot, I’m just amused to death to witness the jostling of the angry mob...Why is it a worthwhile pursuit to skim nano metres of a Perspex shield or mount a see thru’ drive in screen to your bike so as you can have it the way you want, but I want my speedo to work and I’m told it either can’t be done, (which is more than likely correct), or it’s an unworthwhile pursuit.
Really y’all can’t lose.
Either I crash and burn like a bitch and there’ll be a tsunami of mirth and levity throughout the land at the demise of the smart ass, or I soar to success and you’ll see me happier than I’ve been for ages...!
There’s a hint  of passive aggressiveness that’s wafting across the Pacific from some of you guys..
Were I you, I’d feign support for me just for the unbridled pleasure of watching the collapse of my attempts.
Now I know how Noah felt.... ..(Just joking with y’all..)
Jeez I love this stuff...

[piecemealadventurer]

Huzo,
Obviously the bike meets the requirement of the Australian Design Rule the allows a tolerance for over reading but absolutely no tolerance for under reading.  The test will be altering not too much so that it under reads.

[Huzo]

Huzo,
Obviously the bike meets the requirement of the Australian Design Rule the allows a tolerance for over reading but absolutely no tolerance for under reading.  The test will be altering not too much so that it under reads.

That won’t be a drama Mick.
The speedometer is 7% out across the range. A reduction of 48 slots to 45 is 3 slots or 1/16 th.
1/16 th is 6.2% so there’ll be worries there. The result will be a change of an indicated 107 @ 110 k’s to an indicated 101 @ 100k’s.
Anyway, work has begun.
The next post should be a photo taken at 100 kph on the GPS with 101 showing on the digital speedometer
That’s the plan. I’ll document the process with photo’s and text but will wait ‘till the results are known one way or the other.
There’s no one out there that thinks it’ll work, so there’ll be a surprise either way...

[jacksonracingcomau]

Absolutely admirable 

[Huzo]

 

Go on and do it.  Let us know the results.

I don't personally think you'll get the results you expect

Again..
Why is that Rocker...? 

[Knuckle Dragger]

Slots 8 degrees apart, right?

[rocker59]

Again..
Why is that Rocker...? 

I believe the sensor counts slots over a given amount of time, but has no idea how many there are on the wheel.

The computer may count 48 pings as one revolution.  With the 45 slot tone ring, your wheel will make slightly more than one revolution while the computer counts waits until 48 pings to register one revolution. 

But, I'd love to be wrong.  That's why I encouraged you to proceed with the experiment.  We'll all learn something.

[PJPR01]

Very entertaining thread as always Huzo! 

If the tank on your bike was mounted crookedly, you’d want it fixed - not a problem, tank is nice and straight and protected with a tank cover and tank bag
If it pops and farts on overrun too much for you, you’d want it fixed - I like the popping, happens with a stock map or a Beetle Map and a lovely Agostini pipe...it's a feature and keeps the deer away from the road
If she’s not up to scratch for your bucket list trip, you’d want it fixed - runs perfectly...an absolute joy to ride even after 10 years - actually almost to the date since I bought it.

....examples of blokes here who buggerise around shaving microns off their windscreens to minimise wind buffeting - Well in my case, it was an additional 50,800 microns...SWEET quiet air, ZERO buffetting...you should try it next year at Cedar Vale and meet the Sultan while you're at it!

Jeez I love this stuff...

:)  Happy Wednesday!

[Huzo]

I believe the sensor counts slots over a given amount of time, but has no idea how many there are on the wheel.

The computer may count 48 pings as one revolution.  With the 45 slot tone ring, your wheel will make slightly more than one revolution while the computer counts waits until 48 pings to register one revolution. 

But, I'd love to be wrong.  That's why I encouraged you to proceed with the experiment.  We'll all learn something.

As in aviation to remove ambiguity, it’s prudent to use the terms “true” or “actual” speed and “indicated” speed.
Well if you want to approach from that perspective then yes Rocker, I think you are right.
So @ 100 kph the wheel will only get to 45 slots after one revolution so the brains will “wait” for anther 3 slots to pass before spitting out the 100 kph reading.
I think your thought process is slightly awkward in terms of logic, although I’m not qualified to definitively say so.
To my mind the sensor currently sees 715 or so, pps (pulses per second) @ a true 100 k. That’s all the brains knows, it cannot sense velocity, it can only calculate it as a function metres (or slots) per second.
Give it less slots per second then...
All I’m doing is altering the pps @ a true 100 k’s to what the sensor would currently see @ a true 94 k’s.

If I jump on my ‘85 now, and run up to an TRUE 94 k’s as seen on the GPS, there’ll be 656 pps zooming up the wire and my speedometer will read 100k’s.
So..?
I will make my tone wheel so that the sensor sees the same thing at a true 100 k’s, that it used to see at 94 k’s.
See how awkward and unnessessarily complex that sounds ?

Simple way is..
Alter the slot numbers by 6%, and you’ll alter the reading by 6%. When Beetle said it won’t work because I have a 7SM controller (response #37),  I thought I was rooted, but then I thought to keep going because all I’m doing is telling the controller different information.
I thought 7SM was a radio station in South Millimore, Tasmania...!
BTW..
It still worries me that no one thinks my logic is sound.
Looks like if I fail, I’m on my own..
But then again, if I don’t.... ...
Speaking of being on my own..
I’m reminded of my first sexual encounter.
It was a mid Winter’s rainy night...
It was cold, dark and I was all alone..

[rocker59]

I think your thought process is slightly awkward in terms of logic

Yes.  For which, I'm known far and wide!   

[Huzo]

Yes.  For which, I'm known far and wide!   

Hey mate..
At least you’ve bought a gun to the fight..(oh shit, I said the “G” word and to a Mod no less), could we have a section on WG where we can use that word ?
We could call it the G spot...!

[John Warner]

If you have GuzziDiag, you can probably alter the Speedo Correction Factor in the ECU Map.
I’ve done it on my Stelvio several times, once to correct the readout when I fitted the 17 inch Griso Wheel (original is 19”), and a few times to try and get the speedo spot-on, at least equal to GPS speed readings, which it now is.
You’ll also need a program called Tuner Pro (also free) to read and alter the Map.

[Huzo]

If you have GuzziDiag, you can probably alter the Speedo Correction Factor in the ECU Map.
I’ve done it on my Stelvio several times, once to correct the readout when I fitted the 17 inch Griso Wheel (original is 19”), and a few times to try and get the speedo spot-on, at least equal to GPS speed readings, which it now is.
You’ll also need a program called Tuner Pro (also free) to read and alter the Map.

Ok..!
Now you’ve got my attention.
How does one procure this GuzziDiag of which you speak..?
I feel a trip to Paul Brooking’s coming on.
(Actually I’m going to Adelaide today)

[Xlratr]

Adjusting the speedo in a 5AM ECU bike (Stelvio, Griso etc) is easy, but I believe Mark is saying that the speedo factor has not been located in the maps for the newer ECU.
But I can't see any reason why your plan shouldn't work Huzo. The ECU doesn't really know how many slots the wheel has, it just counts how many pass by in a given time and does the simple math. Your idea should work.

[Huzo]

Adjusting the speedo in a 5AM ECU bike (Stelvio, Griso etc) is easy, but I believe Mark is saying that the speedo factor has not been located in the maps for the newer ECU.
But I can't see any reason why your plan shouldn't work Huzo. The ECU doesn't really know how many slots the wheel has, it just counts how many pass by in a given time and does the simple math. Your idea should work.

Now that felt like a breath of fresh air..
I know enough to be wary of ignoring Mark’s counsel on such matters.
But your input suggests that Marks words hold true if I attempted to root around with the electronics..
I can’t even spell electronics..!
I will place your name of the people that I must not brag to, in the event of glorious success. Your’s will be easy to find, you’re the first..

[Kiwi_Roy]

Huzo, I can always count on you to come up with a good topic.
I 100% agree with you that altering the tone wheel by a number of slots will have the corresponding effect on the speedo, I assume its the front that drives the speedo, it will be easy to figure out by rasing both wheels in the air and giving them a spin.
I doubt the speedo even calculates when the wheel has turned a complete revolution, it just calculates the number of slots passing over a period of time
The time period may be a second or it might be a sliding window of several seconds adding counts at the front while tossing them off the back, this makes the count rate smoother.

It kind of reminds me of calibration of a conveyor weigh scale where you calculate force by speed to reach tonnes per hour

I wonder if you have to swap both Tone wheels or if its possible to re-calibrate the system as though you had fitted a different size wheel.

[Huzo]

Huzo, I can always count on you to come up with a good topic.
I 100% agree with you that altering the tone wheel by a number of slots will have the corresponding effect on the speedo, I assume its the front that drives the speedo, it will be easy to figure out by rasing both wheels in the air and giving them a spin.
I doubt the speedo even calculates when the wheel has turned a complete revolution, it just calculates the number of slots passing over a period of time
The time period may be a second or it might be a sliding window of several seconds adding counts at the front while tossing them off the back, this makes the count rate smoother.

It kind of reminds me of calibration of a conveyor weigh scale where you calculate force by speed to reach tonnes per hour

I wonder if you have to swap both Tone wheels or if its possible to re-calibrate the system as though you had fitted a different size wheel.

Thanks KR.
I’ll be making a pair of wheels because I don’t have to pay for my own time and I want to replicate what’s already there, the only difference being the number of slots.
If I make one wheel and it doesn’t work then I’ll not know why and then I’ll have to enter the (for me), dark world of electronic re calibration and such.
This is so beyond me it’s laughable, but I’ll back myself to stand at a lathe and churn out a good product.
I’m just guilty of directing my efforts in a direction where I know I can function.
BTW..
Here’s a shot I took an hour ago with no hands and a lovely cruise control. The error is a touch less than I’ve been spruiking  but seconds after the shot was taken, the speedo adjusted to 106.
So the error is 6%.

[averb]

For what its worth I can't see why your adjustment wont work, surely the ECU is just monitoring the time between pulses and using its known value for the distance traveled between each pulse?
I have been wrong before

Steve

[jacksonracingcomau]

Thanks KR.
I’ll be making a pair of wheels because I don’t have to pay for my own time and I want to replicate what’s already there, the only difference being the number of slots.
If I make one wheel and it doesn’t work then I’ll not know why and then I’ll have to enter the (for me), dark world of electronic re calibration and such.
This is so beyond me it’s laughable, but I’ll back myself to stand at a lathe and churn out a good product.
I’m just guilty of directing my efforts in a direction where I know I can function.
BTW..
Here’s a shot I took an hour ago with no hands and a lovely cruise control. The error is a touch less than I’ve been spruiking  but seconds after the shot was taken, the speedo adjusted to 106.
So the error is 6%.

When I calbrate, I use trip rather than speed. IE go 20 gps km’s see what speedo trip reads
Mine now (electronically adjusted) within 1% over 300km but of course tyre wear will change that a bit
5% over life of tyre to gps trip would be pretty good,
Perfect impossible because tyre both grows with heat and shrinks with wear

[Kiwi_Roy]

When I calbrate, I use trip rather than speed. IE go 20 gps km’s see what speedo trip reads
Mine now (electronically adjusted) within 1% over 300km but of course tyre wear will change that a bit
5% over life of tyre to gps trip would be pretty good,
Perfect impossible because tyre both grows with heat and shrinks with wear

Do you think the odometer is out by the same ratio as the speedo?
There is no reason it has to be.

It would be interesting to do a comparison between the odometer and a runners GPS, they are quite accurate, at least they seem to line up with a measured race distance.

Perhaps Huzo's new Tone wheels will kill two birds with one stone.

[jacksonracingcomau]

Do you think the odometer is out by the same ratio as the speedo?
There is no reason it has to be.

It would be interesting to do a comparison between the odometer and a runners GPS, they are quite accurate, at least they seem to line up with a measured race distance.

Perhaps Huzo's new Tone wheels will kill two birds with one stone.

Acewell digital speedo they are fixed together, tho accurate mpg far more to me than speed
Vaguelia analogue also fixed error, gps never tallied with trip, main reason to dump

programming odo and speedo differently would be a bit weird, why would they ?

Huzo will tell us if v85 has 2 algorythms, if so he’s gonna muckup consumption figures, whodjthunkit?

[John Warner]

Adjusting the speedo in a 5AM ECU bike (Stelvio, Griso etc) is easy, but I believe Mark is saying that the speedo factor has not been located in the maps for the newer ECU . . .

Ah, that's a shame.
I thought I'd seen it mentioned somewhere else, but maybe that was just that GuzziDiag can be used for Mapping on them?

I'm all for making things to fix issues or change things (as one look at my Stelvio will prove), but I think I'd just put up with the slight inaccuracy rather than make new Sensor Rings.
Nice little project though.

[beetle]

But your input suggests that Marks words hold true if I attempted to root around with the electronics..

Aye. That what I was getting at. I never suspected you would attempt to re-engineer things.

I thought I'd seen it mentioned somewhere else, but maybe that was just that GuzziDiag can be used for Mapping on them?

The V85 uses the 7SM, same as the Cali 1400. So yes, remapping is possible. The only difference is the type of connector required.

[Xlratr]

Do you think the odometer is out by the same ratio as the speedo?
There is no reason it has to be.

It would be interesting to do a comparison between the odometer and a runners GPS, they are quite accurate, at least they seem to line up with a measured race distance.

Perhaps Huzo's new Tone wheels will kill two birds with one stone.

Ah, I forgot to mention that. If you adjust the number of pulses for the Speedo by 6%, then the odometer will read 6% less. There's only one source for the signal so you have to choose what's more important to you. Speedo accuracy or odometer accuracy.
From the factory, the odometer is usually quite accurate, but the  Speedo intentionally reads too high. Trouble is, they depend on the same input. (Assuming the V85 works the same as the 5AM ECU)

[Huzo]

Ah, that's a shame.
I thought I'd seen it mentioned somewhere else, but maybe that was just that GuzziDiag can be used for Mapping on them?

I'm all for making things to fix issues or change things (as one look at my Stelvio will prove), but I think I'd just put up with the slight inaccuracy rather than make new Sensor Rings.
Nice little project though.

Hmmmm..
I’d say anyone who’d take a perfectly functioning set of cast wheels off a Norge and build a set of wire ones, has a sense of priorities who’s level of warpage knows no bounds...
I mean, why would you..
Because you can...?


Damn right...!

[Huzo]

Slots 8 degrees apart, right?

Yeah I suppose so KD, but I didn’t really twig to that fact..

[Huzo]

grows with heat and shrinks with wear

Yeah, I thought the same thing when I stopped for a comfort break today and looked down...!

[Huzo]

Do you think the odometer is out by the same ratio as the speedo?
There is no reason it has to be.

It would be interesting to do a comparison between the odometer and a runners GPS, they are quite accurate, at least they seem to line up with a measured race distance.

Perhaps Huzo's new Tone wheels will kill two birds with one stone.

Hmmm...
I hadn’t stopped to think about that. I’ll pick a destination of about 100 k on the GPS and do the trip after setting the trip meter.
That’ll find out the truth..