just got my 27 tooth sprocket and installed it. seems like the bike runs a lot smoother with the small sprocket. I only weigh in around 150, so i can torque it on hills but i don't feel like a sitting duck on the road now. you absolutely can't go slow with a sprocket this small, my ride to work is 7 miles only a couple of stops and a paved shoulder to get on to escape cars, so i think it'll work out pretty good. i've gone thru a 44T, then a 36 and now the 27.