I just put on a 43 tooth rear sprocket and I really enjoy it. I wasn't looking for a major difference and the 43 gives me a little extra pickup down low. I'm sure it will still go as fast as I want it to go, since I don't have a straight away around here where I get over 130.
Haven't noticed any significant difference in gas mileage, but I don't pay that much attention. I have a 4WD van that costs $75 to fill the tank. After that filling the bike is NBD! Probably would have been happy with 44 also but I tend to do stuff in small steps. I've heard that the 16T front makes a little noise.
I did need a longer chain too which is more $ than the sprocket. I especially like that it is reving a little higher in slow zones and parking lots. Without restrictions in the exhaust, it runs a little rough at 15k-25k. This smooths it out some. And then makes a strong get-away!
008 ZX14R Ninja ... Midnight saphire blue with custom lightning bolt paint job, Kenny Rodgers KRTuned mufflers, Corbin custom seat, Marchesini wheels, Dunlop Qualifiers, Dyno Jet PCIII, custom FAICS map, Dyno Jet Ignition Module, K&N Air Filter, Supersprox 44 tooth sprocket, Zephyr 16 front sprocket, EK chain, TRE008, MRA windscreen, Race Railz frame sliders, Sato Racing axle sliders, ST Machine brake & clutch levers, Engine Ice coolant, Muzzy aluminum fan, ceramic coated headers and midpipes (cat removed), Vortex Rear Sets , Pro Comp Stearing Damper, Pro Grip Gel handgrips, Gen Mar clip on risers, Dowco tank bag, and a Rumble fender eliminator.
Removed GPS.
2005 Harley Davidson Dyna Low Rider, 1442 CI fuel injected, 65 HP, lots of chrome with 24K gold overlay detailing. Sure is pretty!