readjusting speedo

is there anyway to readjust the speedo for a sproket mod on the F4i? was thinking about dropping a tooth on the front for an upcoming trakday for better acceleration but would like to know my speed.

i have heard of a product called speedo healer... do a search and it may come up... sorry cant be more help...peace

just found the link..

http://www.speedohealer.com/eng/intro.htm