rpm to speed ratio.
 

need to know what the speed of my 2004 cbr 1000rr should be for 4th, 5th and 6th gear at 4,000 rpm's. Honda of America is asking me to tell them what my bike reads at these rpms. my speedo is off by at least 25% and was replaced in 2008 under a recall. They are giving me a hard time to replace it.

You can see what the different speeds should read for each gear at the Gearing Commander website. Pull up your bike from the drop-down menu and check the "Speed in MPH" chart.

I just looked up yours. The default "Speed in MPH" chart doesn't show speed for exactly 4000 rpm but if you look to the left of it there's a box where you can enter a minimum engine rpm. Put "4000" in that box and it will show you exactly what you're looking for.

If your bike doesn't have stock gearing you can input the aftermarket sprocket sizes near the top of the page on the right under "Current" or "Custom".

Got a smart phone with GPS or just a normal GPS, go for a ride and see what your mph is at that rpm in those gears

But he is asking what the speed SHOULD be at 4000 rpm in those gears, not what it actually is.

Just a heads up that if you did a sprocket swap and changed the ratio, a new speedometer won't do a thing, You will need to get a speedohealer or speedoDRD.