Built with the same core design principles as the pro level zephyr the all new bell stratus road bike helmet 2017 combines lightweight aero efficiency with cutting edge comfort technologies the shape was refined for all around road performancemdashventilated for long climbs but still fast for the flatsmdashand the all new float fit system offers comfort and security with a streamlined fit and an oversized dial thatrsquos easy to adjust with one hand the overbrow vent