GSXR600K3 Digital Speedo vs GPS

**BUBBLE** · 2nd April 2006, 20:11

Tried the accuracy of my GSXR600K3 digital speedo today. Hand held my Garmin GPSMAP60 while riding down a 2 k straight while cruising at 100.

GPS read 92.5km/hr and was consistant for 2 k's. Error of 7.5km/hr.

Ive tried the GPS in 3 cars and 100k on the car speedo's have matched 100k on the GPS.

Has anyone else done this?

**merv** · 2nd April 2006, 20:25

Yeah told you all about it here http://www.kiwibiker.co.nz/forums/sh...ad.php?t=22396

**WINJA** · 2nd April 2006, 21:23

Originally Posted by BUBBLE

Tried the accuracy of my GSXR600K3 digital speedo today. Hand held my Garmin GPSMAP60 while riding down a 2 k straight while cruising at 100.

GPS read 92.5km/hr and was consistant for 2 k's. Error of 7.5km/hr.

Ive tried the GPS in 3 cars and 100k on the car speedo's have matched 100k on the GPS.

Has anyone else done this?

GET A NEW BACK TYRE

**Karitane pete** · 2nd April 2006, 22:28

The power boat boys on the "Scream & fly" forum use GPS to verifiy there boat speed and quote they are good to one decimal place, so I would trust the gps.

**BUBBLE** · 3rd April 2006, 09:02

Rear tire is new and is same size as factory tire.

**ZeroIndex** · 3rd April 2006, 09:33

Originally Posted by WINJA

GET A NEW BACK TYRE

excuse my ignorance (if that's what it is...), but what difference would a new back tyre make? isn't the speedo connected to the front tyre (or is that on crappy bikes like mine... and well, other bikes that aren't crappy...)

**BUBBLE** · 3rd April 2006, 09:40

Originally Posted by ZeroIndex

excuse my ignorance (if that's what it is...), but what difference would a new back tyre make? isn't the speedo connected to the front tyre (or is that on crappy bikes like mine... and well, other bikes that aren't crappy...)

My bike has speedo driven off gearbox, so a change in tire diameter would change the speed thats reads on the speedo.

**thehollowmen** · 3rd April 2006, 09:42

Originally Posted by ZeroIndex

eisn't the speedo connected to the front tyre

Most are connected to the back tyre through the gearbox

If the back tyre is smaller (worn) the tyre has to move around further to move the motorcycle the same disance.

That's the theory. I dunno how much difference it really makes, since it is only a cm or so per revolution at most..

**ZeroIndex** · 3rd April 2006, 10:55

Originally Posted by BUBBLE

My bike has speedo driven off gearbox, so a change in tire diameter would change the speed thats reads on the speedo.

ahhh.... like a cage..... ok... yeah, that makes sense... bigger tyre diameter = higher speed than speedo indicates.

My bike speedo reads off the front wheel... but hey, I just learnt something new

thanks

**WINJA** · 3rd April 2006, 18:49

Originally Posted by ZeroIndex

excuse my ignorance (if that's what it is...), but what difference would a new back tyre make? isn't the speedo connected to the front tyre (or is that on crappy bikes like mine... and well, other bikes that aren't crappy...)

K3 GIXXER 600 READS THE SPEED OFF THE END OF THE LITTLE SPROCKET.
FUCK KNOWS WHAT YOUR HYOSHITA POPUPTOSTA DOES ARE YOU SURE THAT ITS A BIKE DOES IT HAVE A SPEEDO OR A DIAL THAT SAYS 'LIGHTER' OR 'DARKER'

**Silage** · 2nd September 2006, 21:58

Resucitated this oldish thread even tho it went slightly off topic.

Measured the GS today with a GPS (Mrs Jimmie got me one for my 135th birthday) - at 108/109 on the clock showed 100kph on the GPS. That's almost 10% error

I assumed the GPS is quite accurate (as mentioned above by KP) as the speed shown is quite stable. My back tyre is quite new (around 2000km).

I guess that means I can go about 118 before risking a ticket on the open road.

I hope the GPS doesn't transmit to "base" as I also tried some other numbers, but only quite briefly.

Has anyone else checked speedo vs reliable device (speed camera, radar, GPS etc)?

**Cajun** · 2nd September 2006, 22:15

most bikes are build with 5-10% error in there speedos.

I have recently corrected mine due to sprocket changes, and testing it against garmin gps, its with in 1km/h now, i calculated a speedo error of 5.5% and with sprocket changes, worked out to be about 15%

Its handy knowing now when you are sitting on 58km/h thats pretty much what you are doing

**Jantar** · 3rd September 2006, 19:44

I can't understand why manufacturers who use digital speedos cant get them absolutely accurate. My Vstrom has over 10% error. At an indicated 150 kmh (private road of course) the GPS was reading 137 kmh. That's a 9.4 % error.

**SimJen** · 3rd September 2006, 20:08

As long as your GPS works in 3d, then the distance will be accurate as.
If it doesn't and you travel up and down then there is no way it can be accurate.

**Crazy Steve** · 3rd September 2006, 20:15

I was riding next to a friend on his K31000....I could see his speedo reading 88kph....

And my Cbr1100xx was only reading 80kph....At the same time and same speed..

Never really thought about it untill now....

Oh and two weeks ago at the drags...i see 225-230kph through the gates...

But the time sheet says 215kph...

Crazy Steve..