It is going to depend on what bike you have, what stem will fit. You may have to experiment, but it is still usually easier to work with a bike a little too small than one too large. You can, of course move the seat higher and also back. You do need to consider the reach of the stem - and if the bike is a bit small you want a longer reach- as well as the angle, since many do have more or less of an angle. Your own personal geometry will determine what's best. A reputable bike store staff can often do a world of good with free advice and helping you "fit" your bike. Hope this helps.