|
How to use the Gear RPM Range Calculator: A) Measure your rear wheels outer circumference: Push the bike till the valve stem is at the very bottom. Mark the ground next to the tire equal to where the stem is. Sit on the bike and roll forward till the stem is once again at the very bottom. Mark the ground there and measure the distance between the marks. If you measured in inches then put that value at N3 to know the equivalent distance in meters at O3. Enter the wheel circumference meters at K3. B) Put the end of pipe powerband at K1. If you leave it blank then this calculator will use the end of pipe powerband RPM from sheet 1. Otherwise it will use whatever RPM you enter there. C) Put the bike in 1st gear. Take off your ignition cover and prop the bike up so the rear wheel is off the ground. Take the spark plug out. Spin the wheel till the valve stem is at a spot that you can easily remember (such as visually at the top edge of the swingarm.) Mark the flywheel and the cases so the two marks align. Slowly turn the rear wheel while counting the complete turns of the flywheel. Do this till the valve stem returns to its original position. A sloppier but easier way is to hold a pencil in the spark plug hole and count the times the piston hits it. Write down the crank rotations per wheel rotation and put that number for each gear from K9 to K14. D) Take note of the RPM band for 2nd gear. Your pipes powerband should be wider than that so there is suficient leeway as to what RPM you need to be in to shift so that you won't be out of the pipe powerband after the upshift. If you know the gear ratio and bike speed (KPH or MPH) while in a certain gear then in order to find out the RPM just keep entering different RPM at K1 till the right speed is listed for the same gear. You can also use this calculator to find out the gear ratio if you know the RPM and bike speed in a certain gear. In that case just keep changing the crank rotations in the same row as the "certain gear" until the noted bike speed appears in the same row as the noted gear.  |