Here's some info that will tell you what your RPM's are compared to the speed of the bike on a six speed for those without a tach and the 5 speed is shown at the bottom of the page.

http://i149.photobucket.com/albums/s45/bills985/rpmstospeed.gif


And here is a chart for the 5 speed bikes to show the same speed to RPM as above.

http://i149.photobucket.com/albums/s45/bills985/SpeedvsRPM.jpg
(http://www.box.net/shared/dg3sj3l8ok)