im quite short (5ft 4inch) but havnt lowered mine and i dont seen to have much trouble with it. i did drop it once climbing on to it but other than that nothing. i wouldnt recomend lowering the seat it screws up cornering however the bike will be quicker in a strait line (when its de-restricted and lowered you could expect up to 80 to 85mph or more out of this bike if you slightly changed the gearing) personely i prefer being able to go quick round coreners because 85mph in a strait line is not that interesting.