V85 Speedometer inaccuracy

[Huzo]

I'm sorry to rain on your parade but I find that a poor analogy as your on the ground riding your moto and in the air its a safety issue of the highest order. (airspeed)

Yes I know a guy that is in the custom Harley business that tells me that it works well, but I might add this is hearsay and I have no direct experience.

Cheers

A bit of an exercise in semantics (by me), but that was my point Kirb..
IF.... your pitot was wrongly mounted and it was important to YOU to have a correct ASI (I do understand the importance), my thought was...
In an attempt to get a correct reading, would you alter the pitot, or alter the instrument ?
It’s not about WOULD you change the reading to make it correct, it’s about HOW would you make it correct..
Anyone else’s opinion on how worthwhile it is/was, is not the point.
The fact that your life hinges on one (aircraft) and your personal satisfaction hinges on the other (bike) was not lost on me, but debating whether it was a worthwhile pursuit in someone else’s estimation, was not the thrust of the post.
A similar parallel could be drawn by looking at Beetle’s maps.
I could say..
“Jeez, why bother going to all that trouble to build a new map to make the bike run better, mine goes alright..”
I don’t want it allright...
I just want it .....right...
ps.
I don’t think “semantics” was the right word at the top of the post..

[kirby1923]

All due respect...

Ha!
This reminds me of the story of the princess and the pea!

But I gotta say there are many other things pertaining to the operation of the motorbike that are far more important than dead accurate speed, such as safety items.

Your are all rapped up in something that is a common occurrence in all modern motos that I've operated and most of us just make the mental calculation and press on. Its an electronic problem in most cases and can be corrected buy AI?,(oops), easy as that.

There must be marketable opportunities in this terrible malady as someone, (more than one company), has developed a easy fix so your maybe not alone in your quest.

A little 0 and 1 manipulation can correct your problem  in short order...but it'll cost you $$$ (less than $100 US.)

In this thread on page 7 is one answer to your nagging problem, why do it the hard way?? You can dial it up and take a video of some impressive speeds and post it for bragging rights!

Obvious from the many comments here that your valiant efforts to slay the "speedometer error dragon" don't  go unnoticed.

BRAVO!

BTW don't mess w/ my A/S....

:-)

[Huzo]

But I gotta say there are many other things pertaining to the operation of the motorbike that are far more important than dead accurate speed, such as safety items.

Well Kirby, it’s like this.
There’s a bloke who lives not far from me who could wipe the floor with you (and me), on matters of electronic manipulation and buggerising around with 0’s & 1’s.
He says it’s not as easy as wiping your own arse, but he thinks it MAY be possible. So, much loved and revered as you are, I’m putting my trust in his words.
And you don’t “gotta say” anything really, but on the subject of “more important things”, well they have been checked and deemed ok.
Also the word is “you’re” not “your”...

[kirby1923]

Quite right!

Thanks for the grammar/syntax lesson, absolutely know excuse for that....

You're a prince!
:-)

[Moparnut72]

This has been an interesting thread to follow. The speedo on my bike is darn accurate but in certain light condition impossible to see. I haven't checked the odometer. I am going to do that as soon as we have a decent enough day to ride a few miles when I can break loose from other duties.
kk

[Huzo]

This has been an interesting thread to follow. The speedo on my bike is darn accurate but in certain light condition impossible to see. I haven't checked the odometer. I am going to do that as soon as we have a decent enough day to ride a few miles when I can break loose from other duties.
kk

If it’s a V85, your odometer is 1.2% out.
Another recalibration might do the job, but that’s good enough for me.

[Huzo]

know

?

[Moparnut72]

If it’s a V85, your odometer is 1.2% out.
Another recalibration might do the job, but that’s good enough for me.

Audace

[Huzo]

Audace

Wow !
A fabulous bike, you’ve no excuse. You live in California and you own a great bike...
Out you go now, the house will be there when you get back...

[Moparnut72]

Wow !
A fabulous bike, you’ve no excuse. You live in California and you own a great bike...
Out you go now, the house will be there when you get back...

Even though I/live in Calif it is not all sunshine and beaches. The roads were just cleared of all the snow yesterday and they are just now kind of drying out. I did errands today on my bike and it is now filthy. Small price to pay for a bit of riding. The roads are still too snowy out of town to go too far.
kk

[Huzo]

Hey..just thought.
Way back when I tried (unsuccessfully) to fix the speedo error, I had to admit defeat for two reasons.
#1
The gear indicator became innaccurate in 5th and 6th as predicted.
#2
Although I fixed the 7% error in the speedo, it pushed the error into the odometer.
But all may not be lost.
It occurred to me today while I was out on the V85 that in Guzzidiag, there is a parameter that specifies the circumference of the rear wheel, which I wonder whether it is adjustable in Guzzi writer. Now thinking a bit, I’m surmising that the brain only knows how far the bike has travelled by knowing how many revs the wheel has done (tone wheel) x the distance around the perimeter (circumference).
So if I re fitted the new tone wheel that I made which will bring the speedometer back by 7%, that will introduce the error back into the odometer to the tune of 7%.
But..
If I was to get into Guzzidiag and increase the circumference figure by 7%, would the brain then compute that as an increase of 7% in distance travelled for a given number of revolutions and thereby bring the odometer back into line, without buggering up the pulse frequency (speedo reading..).
I would be left with the gear indicator issue, but I could live with that easier than a faulty speedo.

[Huzo]

Bump for Wayne Orwig.

[Huzo]

Hey Vagrant !
Reducing the diameter by that amount may be achievable by performing an on board re calibration.
It will not have a bearing on the speedometer etc. as I understand it, because that data is pulled from th3 rear tone wheel.
Also if you are thinking of changing your front wheel as a lowering measure, you can achieve the same by raising the forks in the clamps and winding pre load off your rear shock.
I got mine down by 20 cm.
I think it shows in this shot.

[Vagrant]

I've got my forks dropped to the third line on the top of the tubes. About 1/2". The rear is on the lowest pre-load and the seat rubbers are removed. I can live with it this way, but I considered a new 850 V7 to replace my old EV I keep in Az. But by the time you add 3 bags, mounts, fork springs, and decent shocks I might as well buy another V85 and have the full power too because the loaded V7 gets right to the price of the fully equipped V85 in the states.  FYI, 27 1/2" inseam and 73 years old.

[Huzo]

I've got my forks dropped to the third line on the top of the tubes. About 1/2". The rear is on the lowest pre-load and the seat rubbers are removed. I can live with it this way, but I considered a new 850 V7 to replace my old EV I keep in Az. But by the time you add 3 bags, mounts, fork springs, and decent shocks I might as well buy another V85 and have the full power too because the loaded V7 gets right to the price of the fully equipped V85 in the states.  FYI, 27 1/2" inseam and 73 years old.

Yes ok.
Mine has an Ohlins shock which I can get the rear down to required height. In the shot I posted, you can see the difference in distance from the top of the reflector on the front fork, to the bottom of the lower clamp.
It shows how far the forks are raised and the angle of the swingarm to gearbox centreline on mine is noticeably straighter than the standard one.

[Trialsman]

Huzo, I forget if I ever told you, but you can get a little more with the Ohlins.  I took off one of the two retaining nuts from the spring tension and tapped in for a set screw in the remaining one.  Although this only affects the preload with about 1/4", it did give me a little more sag and it was just right.  It is a possibility.

[Huzo]

Huzo, I forget if I ever told you, but you can get a little more with the Ohlins.  I took off one of the two retaining nuts from the spring tension and tapped in for a set screw in the remaining one.  Although this only affects the preload with about 1/4", it did give me a little more sag and it was just right.  It is a possibility.

Yeah you did Trialsman.
I did not think of it myself, but it’s a good idea.

[Vagrant]

Did you have to cut the side stand with that much drop?

[Huzo]

Did you have to cut the side stand with that much drop?

Yes I did a bit.

[Trialsman]

I dropped mine and cut the sidestand as well.  No problem, and you can add an oversized foot for soft surfaces with very little work as a bonus.

[Huzo]

I dropped mine and cut the sidestand as well.  No problem, and you can add an oversized foot for soft surfaces with very little work as a bonus.

Yep.

[Huzo]

It never worried me that my Griso wasn't a 1400. I was happy to be a guinea pig. Having said that, I couldn't go back to a 1200. The grunt is intoxicating.

How much “grunt” does a Guinea pig actually produce…?
(An old thread, but I simply could not help myself…)

But..
After reading through the whole thing again, I’m wondering if I’ll churn out a new front tone wheel just for the fun of it and throw it in the ‘85.
I honestly cannot be bothered dragging up the dusty old remnants of my meagre knowlege, trying to reason whether a new front tone wheel will bring things back, but I DO know I can build one.
I think I might do it just to close the book on the whole saga.
A new front ring will bring the two wheels back into line relative to each other and if the rpm gets it’s information from these (which I doubt), I may just get away with it all.
I cannot see how I’ll succeed, but building one and fitting them both will answer all questions.
I may end up not knowing exactly WHY it works, I’ll just know that it does.