Cure for Speedo Error?

[ctfjr]

Several years ago I purchased a "Yellow Box" from a company in Australia. It is a electronic correcting device that goes in line from the wheel sensor. You can make your speedo read anything you want +/-

ahh here is the link https://www.yellr.com/ - they still exist

 

[Patriot]

both my last bikes...Vulcan Cruiser and classic ole Goldwing were pre GPS and I had mounteda wired (not the more expensive wireless model) Sigma BC1200 (Sigma 2610) bicycle computer

I love those things and they were in some ways easier to manage than my Zumo

I kept them and still used them after my purchase and mounting of the Zumo

I've used Sigmas on many of my motorcycles. As stated, they are dead accurate once calibrated up to any speed the FJR is capable of attaining. I currently have them on both my Derbis and had them on my R1 and VTX1800 as well. The no-frills models are the best, as they're easy to use even with gloves on. Plus, they don't clutter you up with a bunch of crap you don't need, like "cadence". Opt for the "rear wheel pickup" if available, because you get a much longer lead...necesary for motorcycle apps. Or you can just splice it like I did on a couple of mine.

Speedometer and odometer are independent. You can change the speedo with no effect to the odometer.

Alan, how is that possible? They both come from the same speed sensor and you're modulating that signal. What am I missing??

the story I'm told is motorcycle manufacturers purposely put in error showing faster than actual for "safety" and liability reasons...and for statisical reasons, the odometer has to be accurate for recording correct miles on the vehicle

the sensor signal goes through a different algorithm and calculation chip to each separate instrument

sounds reasonable to me in these silly days.

 

[Spud]

So if mounting a car tire corrected it then the diameter of the car tire must be slightly larger than an MC wheel, correct?

 

[Patriot]

So if mounting a car tire corrected it then the diameter of the car tire must be slightly larger than an MC wheel, correct?

I think that's right...but ya balls will still fall off... :blink:

 

[user 213]

So if mounting a car tire corrected it then the diameter of the car tire must be slightly larger than an MC wheel, correct?

Yes, that is correct. The 180/55-17 moto tire has a diameter of 24.8", the 205/50-17 car tire has a diameter of 25.1" (for the BT 019G tire I am using. Some others are slightly different.)

 

[HaulinAshe]

GPS

+1 on the GPS!

I've considered fabricating a GPS mount that fits directly over the speedo bezel. If it wasn't for the reach distance to press the screen, my speedo would have been gone long ago.

 

[Dangerous Dave]

the sensor signal goes through a different algorithm and calculation chip to each separate instrument

Hmmmmm, well there's no date on this (don't know if the reference is for 1st gen, 2nd gen, or both), but this is copied and pasted from Speedohealer's FAQ page:

"5. Will the SH calibrate both my speedo and odometer?

Yes, but it is not possible to calibrate them separately, as one speed signal drives both the speedometer and the odometer.

You can get 100% accurate speedometer AND 100% accurate odometer only on those bikes, which have zero "speedo-to-odo" error ratio (see FAQ #16) built-in, such as the Yamaha FJR1300.

On most bikes, if the speedo is calibrated to be 100% accurate, the odo will register slightly less miles. While this can be annoying in certain situations, one can always calculate the real distance easily after a long trip."

I'm inclined to believe this since it is one speed sensor signal, and as far as I can tell, you're modulating that signal before the ECU. So it has no idea it's being screwed with, it just believes what it's being told. But I'm still open to other explanations.

Several years ago I purchased a "Yellow Box" from a company in Australia. It is a electronic correcting device that goes in line from the wheel sensor. You can make your speedo read anything you want +/-

ahh here is the link https://www.yellr.com/ - they still exist

I bought two of those for cheap back when the R1 forum did a group buy. Still have one on my Tacoma to compensate for the 33" tires. Ironically, the R1 needed more correction just due to speedo error than the Tacoma needed for 2" taller tires. Would it really be such a crime for a bike to have an accurate speedo????