Hi there, I've got a Suzuki DR200 (I know, not a "real" motorcyle) which I enjoy for trail riding and enjoy it's street legality as a dual-sport. Gas prices have caused me to consider this recreational bike as a daily work commuter - however the gearing is a bit low for some of the surface streets I will need to follow. Where can I find a source for a taller fifth gear? Should I just change the rear sprocket? What's the advice for making this thing less low-end power and more higher-end speed?