Bike Ahead Composites THREE ZEROThe 30 mm rim, the heart of our THREE ZERO wheelset, does many things differently from conventional rims. The innovative Safe Wing profile allows the tire to support itself wonderfully and roll smoothly over the rim. This is an advantage that can be directly experienced with low air pressures and wide tires. You can lower the air pressure by 0. 2 bar on average without risking a smearing or tilting of the carcass. This significantly increases grip,