With that set up you where probably going around 160 mph.

 

Hate to break it to ya, but with a -1/+2 sprocket change with a normally worn tire, you have about a 19% speedometer error. So, 177mph indicated = 143mph actual. The -1/+2 will also lower top-end for the low-end torque. You can wheelie easier, but you'll be lucky to get 155 mph anymore.

Check out this site, been using it for a while, pretty neat:
Gearing Commander

 

New Bikes have digital speedo's
there is no eddy current error.
a digital speedometer should contain the same amount of error all the way from 0 to 299 since the display is only capable of displaying that speed.

also 5% error at 300kms/h is only equal to 15kms/h which isnt that much..
However my gsx-r does have an eddycurrent type speedometer. My car does not however.

Thank you for the info on the reg's though. Informative. where did you find it?

 

so now im confused i though speedos were off by a percentage, which the faster your speedo read the further it would be off. especially since the gear ratio is changed. am i wrong in this assumption?

 

True, I used the eddy current as an example to show that a speedometer could be off at a different rate based on higher speed. It is possible to program it to show different error percentages, though to be fair, haven't seen that since the 80's. For a time, all digitals here in the US wouldn't display over 186 mph (and years ago, they topped at 80 mph on the speedometers).

The 5% error is a US standard, so when you change it to kilometers, you get about a 6% error. That only works if you have a US spec bike and can easily switch from mph to kph. If it is fixed to kps, it's probably using one of the UNECE (United Nations Economic Commission for Europe) standards. Most people also forget how much tire wear or simply underinflation affects the speedometer, up to an additional 5% or so.

Always been interested in speed measurement, worked for a time at a shop that did speedometer repair and calibrations, also worked on doppler traffic radar (even taught traffic radar at the police academy). The two major UNECE standards are here: UNECE Vehicles, UNECE Two-Wheeled Vehicles

No, you're generally right. And changing sprockets has a dramatic effect. Doing the -1/+2 change can make the error go to around 18 - 20% depending on tire wear (reading considerably higher than what you're doing).

 

all well and good and right and wrong -
All I know is John is an engineer and has a very trick speedo calibrator on his RC51, he was doing 165 when I pased him
My 952 has the new 15/45 setup on a 520 pitch, new Pirreli (sp?) Diablos, a pretty tight tune and 4-2-1 titanium headers with D&D can -

Whatever the 'actual' speed was I was haulin' a$$ and havin a blast!

 

Then it's all good!!

 

That all makes sense!!
I have a us spec bike my speedo can be switched at the push of a button.
ill use my GPS next time im out to compare it.

I hate being lied to i want mt speedo to tell me exactly how fast i am going.

Now does any one know how accurately your consumer gps will be able to calculate your speed?

 

As far as i know they are pretty acurate
My car is limited at 140 from factory.
The gps was showing 141

 

They're pretty accurate, just the cheaper ones don't sample fast enough, so you have to hold the speed to let it stabilize. I got a Speedohealer for my 954 and used my track bike's GPS laptimer to see actual speed and calibrate the speedohealer.