gear ratio calculator script for car/motorcycle.

gear ratio calculator script for car/motorcycle.
- you can examin new sprocket and new tire.

You can check max-speed and relationship between any gears.
This site help you to choise sprocket and gear position in racing course.
for bicycles is here Japanese version is here.

select machine
select tire

please fine adjust after selecting machine.
if you don't find your machine, input data direct.

1st ratio	2nd ratio	1s	2s	3s	4s	5s	6s	revlimit	shift

drive	driven	tire peri	accuracy	graphsize	mile/km

reffer URL can bookmark your machine.

This tool has made for calculating the speed(MPH,km/h) for a given transmission gear ratio.
You can select any motorcycles and cars and calculate speed.
And you can change any parameters(sprocket, tire, revlimit, etc..).

Speed calculating formulas are as follows.
speed = (RPM*60) * (tire peripheral length) / (final gear ratio)
tire peripheral length = Diameter * Pi(3.14..)
Diameter(mm) = width * (aspect ratio/100)*2 + size(inch) * 25.4