Speedo correction?

[patmahoney]

I remember reading one time here that you can correct the speedo in accuracy by installing a different size tire; Is this correct, and if so, what size tire?

Thanks

[dogdoc]

alot did the metzler 180-16 rear which is a size bigger than stock. that makes the error not 10% but about 3-5% at normal driving speeds. Now alot arent going to that brand because they cup pre-maturely. Alot are going Avon Cobras including myself. Hope this helps.

[patmahoney]

Thanks Doc

[Yellow Jacket]

If you presently have a 10% error with the stock size tire (which is pretty much normal) you would need to go to a tire with a diameter of right at 28" to remove all the error. That would require a 195/80-16 tire. If you could even find one in that size you would have to modify the angle brace in the right front corner of the swingarm to provide proper clearance.

If you go with the size that BlownDodge is using, I think it's a 185/75-16, you can correct all but about 2-3% of the error.

If you really want to have the speedometer be as near as possible to reading right on regardless of the size of the tire you are using, you might want to consider buying a "Speedohealer." That can be adusted for any size tire.


Be aware though, if you get the speedometer dead on the odometer will be slow by about 7%.

Check it out here:

http://www.healtech-electronics.com/

[robert]

http://www.miata.net/garage/tirecalc.html

[markw]

[quote author=bob board=general thread=12061 post=195230 time=1246915777]
Be aware though, if you get the speedometer dead on the odometer will be slow by about 7%.

Bob,

Are you sure this is correct? I thought if the speedo was wrong the odo would be too...

Mark

[strobe]

Bob,

Are you sure this is correct? I thought if the speedo was wrong the odo would be too...

Mark

Bob is correct, my odometer is dead on, but the speedometer is out by around 10% at ~60 mph. I have heard that the speedo healer does this on several forums, and I have not installed mine (that I have sitting in the garage because I ordered it before I knew) because I do not like that side effect.

[chuckster131]

For the 1500 the 180 tire is to wide for the rim. Best you can do is the 160, and that doesn't correct the speedo issue. The speedo-healer will make it right on for sure. I installed one on my 01 and it is dead on to the gps in both speed and miles.


I remember reading one time here that you can correct the speedo in accuracy by installing a different size tire; Is this correct, and if so, what size tire?

Thanks

[bfancett]

I have a 2008 1600 and I am pretty sure the rear tire is 170. Can the factory rim accomodate a large tire, and if so up to what size?

Brian

[blowndodge]

Some are running a 205 series CT but that is pushing it...

[patmahoney]

Okay so what I am hearing is that even though the speedos are off by 10% that the odometers are accurate? And if I fix the speedometer I will throw off the odometer?

I guess I will live with the speedo problem as I would rather have the odometer accurate for fuel usage estimates.

Thanks to all.

[patmahoney]

For the 1500 the 180 tire is to wide for the rim. Best you can do is the 160, and that doesn't correct the speedo issue. The speedo-healer will make it right on for sure. I installed one on my 01 and it is dead on to the gps in both speed and miles.


Chuckster, what brand speedo healer are you using, was your odometer accurate both before and after the install ?

[waterman]

I don't think the odometer issue is correct. With the stock, the odometer was off less than 1% and the speedo was 10% off (by gps on both). With the 180/60 E3, speedo is off by by less than 5% and the odometer is off less than 1%. If the odometer was going to change with a tire change that should have done it.

[blowndodge]

My speedometer was about 10% fast and the odometer was about 5% fast. Now my speedo is about 3% fast and my odometer is about 3% slow. I thought it a fair split.

[ells]

I don't think the odometer issue is correct. With the stock, the odometer was off less than 1% and the speedo was 10% off (by gps on both). With the 180/60 E3, speedo is off by by less than 5% and the odometer is off less than 1%. If the odometer was going to change with a tire change that should have done it.

Kind of hard to explain the tire size changing the speedo error but not affecting the odo, what you drink'n these days? Then again, hard to argue with the GPS results, better check again..

[strobe]

The speedo-healer will make it right on for sure. I installed one on my 01 and it is dead on to the gps in both speed and miles.



If this is the case that is great. First time I have heard anyone say that it does not throw the odometer out. I may have to install mine and see....

[Yellow Jacket]

It seems that different bikes have different amounts of error.

However, on the 1600's it appears that the majority have a 10% fast error on the speedometer with the stock rear tire.

For the odometer it appears that there is a range of error from 3% to 5% fast with the stock rear tire.

My speedometer had a 10% fast error and my odometer was 3% fast with the stock rear tire.

On the 1600's the speedometer and the odometer run off the same sensor pulses so any adjustment to the speedometer, whether via changing the tire size or installing an electronic device such as the "SpeedoHealer', will also affect the odometer.

[skeeter]

Been running 180/70/16. Close enough. Looking back I probably would have taken the issue of error up with the dealer. May not have done any good but I still should have brought it up. Might have gotten a speedo-healer out of the deal. I will on the next bike. I knew before I got this one that it was an issue and what people were doing to fix it.

[chuckster131]

I have the one by Heal Tech model SH-V4 + SH-K02 no problems with either the speed or milage readings anymore. I have the unit set at -7% and it is darn near right on the money to my gps.



For the 1500 the 180 tire is to wide for the rim. Best you can do is the 160, and that doesn't correct the speedo issue. The speedo-healer will make it right on for sure. I installed one on my 01 and it is dead on to the gps in both speed and miles.


Chuckster, what brand speedo healer are you using, was your odometer accurate both before and after the install ?