Alex, there is a up and down side to all gearing. If you increase your teeth on the primary gear you make your gears taller. (more top end, longer gear time before shifting, lower RPMs at highway speed) In return for that you loose the quick snap off the line and the high torque through 2nd gear. Once past 2nd gear you are about a gear apart if you go up two teeth. Example would be a 17t gear in 2nd at 4,000 would probably have the 19t gear still in 1st.
Many on the board have moved to a 18t primary gear, you probably are at 17t and find yourself reaching for that elusive 6th gear.
I have a 19 tooth primary and will never switch back. Its up to your personal preferences the bike can handle 16,17,18,or 19 tooth primary gears and run well with all of them.
