Well when i first got my bike in november it came with 9t front and 48t rear but i found that way to slow. So i found i spare 43t in my dad's garage that made the bike quite a bit quicker. But you see the front 9t sprockets are useless because they are so small, after a while they start to make funny noises (simaler to the noise of the chain) so i decided to change the front to a 10t and the rear to a 42t & now it's just right for me it's just how i like it, i found 9 and 48 way to slow.