How do bike helmets perpetuate a culture of secrecy and lack of transparency in the cycling industry, particularly when it comes to crash testing and safety standards, and what role do manufacturers play in promoting a lack of transparency in their testing protocols and data sharing, and is it possible that this secrecy is driven by a desire to protect proprietary technology and intellectual property, or is it a result of a lack of regulatory oversight and industry-wide standards for safety testing and reporting, and what are the implications of this secrecy for cyclists who are seeking to make informed decisions about their safety gear, and how can we, as a cycling community, work to promote greater transparency and accountability in the industry?