Would you like a different answer?
Mine is a 96" T/C with a 'Thundermax with Autotune',SE slip-ons and an air filter added. I also have a set of S & S 583 cams fitted. I have long talked about and considered altering my gearing; but it was always in the 'too hard" basket.I have various posts on this theme over the years.
In MY opinion and with MY 2008 6 speed,i consider it overgeared.Late last year i'd finally overcome my reticence on this matter and did a lot more research.
My bike has a 32t front pulley and a 66t rear pulley as standard.I decided to adjust my gearing by going 9.28% SHORTER. I fitted an Andrews 30t front pulley(6.25% change) and an RC Components 68t rear(3.03% change).
As mentioned this gives a 9 odd percent gearing change.The reason I went like this was that I knew I would be able to retain the standard drive belt;and as my bike has 8500 klms on it this was a worthwhile thing to do.My axle position is pretty much where it was before the change.(it went rearwards with the smaller front and forwards with the larger rear).
Plus,i didn't think a 6% change was enough: particularly when I calculated out engine RPM's versus road speeds.
Standard,my bike at 60kph(our town speed limits) runs 1955 RPM in 4th gear.Too low for 4th and too high for 3rd.A real pain---.
Front pulley only raised RPM's to 2077 ; rear pulley only was 2013 RPM's and both-as I run now-raised them to 2136. A world of difference and do-able with my engine mods. Doesn't sound like much,but makes a great difference. MUCH more pleasant around town.
On the open road at 100 kph revs were 2344 and now they're 2561.Again, a world of difference.As I rarely even ride at 100kph or beyond, the increased RPM's don't bother me.Fuel economy is pretty much exactly the same or even a little better.The most important thing as far as i'm concerned is that the bike is so much better to ride FOR ME.MY way of riding might not be like yours,but it is a worthy thing to do.
With my Thundermax I was able to fiddle around with the speedo calibration numbers until I got my speedo reading correct.If you don't have a T/max I think a company called 'Speedohealer" makes a unit that you can fit to your bike to recalibrate the speedo.
Also,there is or was,a pretty useful Transmission ratio,pulleys and speed conversion chart on "Andrews Products" web site.Or you can calculate it all out.
You can send me a PM if you want to know any specifics.