So, found this calculator.. seems pretty cool.

http://pw1.netcom.com/~sgalaba/mph.htm

You enter you tire width, hight and rim size.. add transmission gear and diff ratio and it tells you what speeds at what RPM...

It's in MPH so you'll have to multiply the result by 1.6 to get kph...

but pretty cool anyway, thought I might share that with everyone.

This dude here has listen the ratios and what not for EL etc..

http://www.trueblueford.com/EL_Gear_Ratios.html

Rockin...

Thanks for those mate, makes it easier to figure out whats what with ratio changes!

Similar calculator.....

http://www.angelfire.com/fl/procrastination/rear.html