While it’s often true that a very narrow kart will not be as stable, and, as an aside, a SUPER narrow kart will just bog the engine down, that doesn’t mean that it’s not drivable. Though it’s advisable when driving a new kart, to start the rear width near or at the max width, you ultimately need to put it where it’s going to go fast whether or not that’s at 55″ or 53″.