Zipp set out with one clear goal design the best performing carbon stem ever the sl sprint is optimised for the stiffness required by pro road sprinters while still being light weight just as cyclists maximize performance by being as light but as powerful as possible the sl sprint stem strikes the ideal balance of stiffness and lightweight to deliver responsive handling without wasting a single watt the stem weighs in at just 18g per newton meter of stiffness howd we do that the s