I Need information on gearing. I am buying a 13,14 and 15 countershaft sprockets and need to know what size of rear sprockets I need. Anyone that has a ttr or something equivalent please reply asap. I am new to mini motards and trying to get ready for up coming OHR race not this weekend but next so I am in a time crunch. Thanks.If you would rather call me thats fine also 409-719-1566. Thanks Again.