Speedo reads high, we all know that, but does the odometer also? Look inside to find out.

[Hayabusa Wannabe]

I believe odometer is spot on, speedo not

1 mile equals a mile on odometer

Let me know if I am missing something.

It cannot be perfect but it must be a trade-off, not due to programming but due to geometry. On a turn the tires are on a smaller diameter. But the bike cannot know this change. Thus if the odo is dead on in a straight it would be far off on the turns, and vice versa. Unless for the gen 3, if the measured lean is actually taken into account and run through a calculation.

 

[TonyM995]

Let me know if I am missing something.

It cannot be perfect but it must be a trade-off, not due to programming but due to geometry. On a turn the tires are on a smaller diameter. But the bike cannot know this change. Thus if the odo is dead on in a straight it would be far off on the turns, and vice versa. Unless for the gen 3, if the measured lean is actually taken into account and run through a calculation.

The bike definitely knows the lean angle from the IMU. I haven’t seen the code in an ecu but I’d bet it’s an insane amount.

They can probably take the front wheel speed sensor input and have code to modify the odometer output based on lean angle.

Even if that’s not the case I doubt you can ride the bike leaned over enough to make that big of a difference.

Disclaimer!!! I have no clue what I’m talking about and you should take what I’ve said above with a grain of salt.

Also notice how the bike applies rear brake if you use the front brake hard enough- even if you don’t touch the rear brake.

That output seems to be modified based on input from the IMU and supports my theory that it’s possible to use those IMU readings to manipulate outputs.

 

[RedBusarider]

I have a GEN 1 and went down 2 teeth on the rear sprocket and went to a series 55 rear tire.
My speedometer is dead on with my GPS.

With that said what is this talk about the speed being read off the front wheel?
Is that the way it is on a Gen 3 ?????
Has anyone put there Gen 3 up on a rear stand and started the bike and put it in gear to see if
the speedometer needle moves with just the rear wheel turning?

 

[smithabusa]

I have a GEN 1 and went down 2 teeth on the rear sprocket and went to a series 55 rear tire.
My speedometer is dead on with my GPS.

With that said what is this talk about the speed being read off the front wheel?
Is that the way it is on a Gen 3 ?????
Has anyone put there Gen 3 up on a rear stand and started the bike and put it in gear to see if
the speedometer needle moves with just the rear wheel turning?

Gen1 and gen2 get speed signal from front sprocket sensor which is tied to the rear wheel. Gen3 dunes from the front wheel

 

[Kiwi Rider]

Gen 2 ABS has speed sensors and tone rings on front and rear wheels for the wheel speed data collection to be sent to the ABS system… I always assumed it uses this for speedometer readout, I’ve never looked at the Gen 2 front engine sprocket to verify whether it has a speed sensor…. Aaaaahh I’ll have to check on this.
Ok, I’ve looked at the parts diagram and it doesn’t appear to have a sensor on the front sprocket.
So it’s not just the Gen 3 that uses solely the wheel speed sensors for the speedo reading.

 

[smithabusa]

Gen 2 ABS has speed sensors and tone rings on front and rear wheels for the wheel speed data collection to be sent to the ABS system… I always assumed it uses this for speedometer readout, I’ve never looked at the Gen 2 front engine sprocket to verify whether it has a speed sensor…. Aaaaahh I’ll have to check on this.
Ok, I’ve looked at the parts diagram and it doesn’t appear to have a sensor on the front sprocket.
So it’s not just the Gen 3 that uses solely the wheel speed sensors for the speedo reading.

Sorry this isn't correct, gen2 does have a speed sensor on front sprocket and does not use wheel speed sensors from abs system for speedometer

 

[Kiwi Rider]

Sorry this isn't correct, gen2 does have a speed sensor on front sprocket and does not use wheel speed sensors from abs system for speedometer

Ok, thanks for clearing this up, I’ve never replaced a front sprocket on a Gen 2 and have never visually seen one.
I’ve learned something new today, learning is a good thing!

 

[TonyM995]

Ok, thanks for clearing this up, I’ve never replaced a front sprocket on a Gen 2 and have never visually seen one.
I’ve learned something new today, learning is a good thing!

Good job for thinking through this yourself because you came out the other side with knowledge you won’t forget.

I think that’s the best way to learn and now you can teach others to solidify that knowledge even further. That’s my goal and I expect to be wrong at times.

 

[Kiwi Rider]

Good job for thinking through this yourself because you came out the other side with knowledge you won’t forget.

I think that’s the best way to learn and now you can teach others to solidify that knowledge even further. That’s my goal and I expect to be wrong at times.

Thanks mate for the words of encouragement and the positive attitude that went along with it . . . Mr @smithabusa is a great bank of knowledge and I always look at every thread he's started and every comment he makes, hey, no-one has ALL the knowledge but he comes close lol, and I learn so much re the electronic/electrical design of the Busa.
I reckon that amongst all the oRg members here, we probably have 99.9% of the know-how with the Busa mechanical and electrical engineering design down pat.
It's funny, I've replaced a lot of chain/sprockets on many different bikes at my job, but never a Gen 2 Busa. No doubt I'll do one soon lol.