A bicycle helmet system comprising a helmet and a chin bar is disclosed. The chin bar is removably coupled to the helmet and wrapped circumferentially around a portion of the helmet. The chin bar may include a rear buckle configured to tighten the chin bar around the helmet. The chin bar may also include two side buckles that engage with side recesses on the helmet when the chin bar is removably coupled to the helmet. The chin bar may also include two alignment protrusions positioned to engage with alignment recesses on the helmet when the chin bar is removably coupled to the helmet.