Thank you braham

can you please tell me how to get all the dimensions of the gear and shaft.... we are working on a project to design transmission system of atv... we are unable to find basic dimensions / data for starting our calculation for drivetrain design.... we refered the service manual of the atv... but only gear ratios were given...
we needed cetre distance, gear diameter, etc.... can you tell me where can i get bsaic datas. so that i can use them to calculate further things like force and all...thankyou very much

@ akash are you talking about this model or in general? i create tutorial how to design a gear there you can find all the dim. for gears. http://www.youtube.com/watch?v=-cRxoSNz03v

i don't know what exactly you want to design, but i think you should start from gear ratio pick pair of gears, then you find they dim. then calculate forces and the rest.