I have seen a few posts recently about speedo correction factors and gearing so I thought I would post up a chart that shows exactly what percentage error you will have for a given sprocket size.
If you have no idea about what gearing you would like and how it will affect your bike it is also worth noting that the percentage in the chart can be applied to your top speed and RPM for a given speed.
A couple of examples:
If you used to run at about 5.5k rpm doing 80kph and you do a -1/+2 conversion on your 03 your new rpm will be about 6k rpm (10.4% increase)
If your top speed was 167mph on your 03 and you do the -1/+2 conversion you new top speed will be around 150mph (10.4% decrease).
The math to work this out for yourself is nice and easy, here is the equation:
% = 100 * (A - B) / A
Where A is the stock gear ratio, A = (# of front teeth / # of rear teeth)
which for your 03 -06 would be (16 / 43) = 0.372093
and for your 07-10 would be (16 / 42) = 0.380952
Where B is the new gear ratio, B = (new # of front teeth / new # of rear teeth)
I have also attached the spreadsheet this screen capture is of if anyone is interested, you just have to unzip it.
Hope someone finds this helpful.
I thought I'd add this post from rr3 just for a little more info on gearing ratios and the like:
If you have no idea about what gearing you would like and how it will affect your bike it is also worth noting that the percentage in the chart can be applied to your top speed and RPM for a given speed.
A couple of examples:
If you used to run at about 5.5k rpm doing 80kph and you do a -1/+2 conversion on your 03 your new rpm will be about 6k rpm (10.4% increase)
If your top speed was 167mph on your 03 and you do the -1/+2 conversion you new top speed will be around 150mph (10.4% decrease).
The math to work this out for yourself is nice and easy, here is the equation:
% = 100 * (A - B) / A
Where A is the stock gear ratio, A = (# of front teeth / # of rear teeth)
which for your 03 -06 would be (16 / 43) = 0.372093
and for your 07-10 would be (16 / 42) = 0.380952
Where B is the new gear ratio, B = (new # of front teeth / new # of rear teeth)
I have also attached the spreadsheet this screen capture is of if anyone is interested, you just have to unzip it.
Hope someone finds this helpful.
I thought I'd add this post from rr3 just for a little more info on gearing ratios and the like: