I just changed out to an 18 tooth sprocket yesterday... I've only put about 40 miles on, but so far, I don't think I'll be changing back. Second Gear = 60 mph & time to hit third... perfect. I didn't find myself looking for another gear either.
Install was pretty straight forward. Some notes:
a] The thin washer behind the sprocket nut is bent to keep the nut from loosening. Make sure you bend it flat again before removing the nut.
b] The nut is 36mm. You may need to buy a socket.
c] Loosen the nut before you loosen the chain. You will need to use the rear brake to hold the output shaft from turning. Engine compression isn't strong enough to hold it.
d] Since I had a 3/4" socket & a 3/8" drive torque wrench. I had two adapters between it & the torque spec was of no use. Instead, I used the German method: "UGH..UGH..Gooten-tight" I'll recheck it in couple hundred miles to see if it loosened up any.
e] After you loosen the rear wheel & give some slack to the chain, I found it easier to put the sprocket inside the chain & reinstall all of it together.
