Do you need a bike helmet? You wouldn’t think that would still be a controversial question, but it is. The antihelmet contingent offers arguments such as: “Forcing people to wear helmets makes cycling seem dangerous,” and, “It discourages exercise.’’

Helmets aren’t a panacea, but you should wear one. Here’s why: Eighty-seven percent of the bicyclists killed in accidents over the past two decades were not wearing helmets, according to the Insurance Institute for Highway Safety. And when it comes to nonfatal injuries, a 2013 review by a committee at the Institute of Medicine found that wearing a helmet during sports reduces the risk of traumatic brain injury by almost 70 percent.


Protecting against impact: Traumatic brain injury is a catchall term used to describe a spectrum of head injuries from concussions to skull fractures. Safety standards are designed to measure a bike helmet’s protectiveness on the catastrophic end of the range — the realm of skull fracture, severe brain injury, and death.

Of the 23 helmets Consumer Reports put through its impact tests, all absorbed the force of impact within the limit set by the current Consumer Product Safety Commission, and 22 received at least a very good rating for impact resistance in its tests.

Determining how well helmets protect against concussion — which can be serious, but not in and of itself life threatening — is trickier. The brain is a gelatin-like structure surrounded by fluid, which acts as a cushion against shock. A blow to the head or a violent movement (such as whiplash) can cause the brain to slide or rotate inside and bump against the skull. That can disrupt normal functioning and alter brain chemistry.

You can’t always “see” a concussion on a CT scan or an MRI, and there is still plenty that doctors don’t know about the condition. If there’s no objective test to show whether someone has a concussion, it’s difficult to design a test to see whether wearing a helmet protects against one.


But the bottom line on helmets: They work.

First, it’s undisputed that helmets are very effective at reducing your odds of suffering a moderate or severe head injury if you fall. And though they may not protect against all concussions, chances are they help at least a little.

It’s all about the fit: No matter how well a helmet protects, you’re not going to wear it if it’s not comfortable or difficult to adjust. So Consumer Reports also looked at ventilation, weight, and fit adjustment.

Combining the scores with those of its safety tests, the Scott Arx Plus, $150, came out at the top of its adult helmet ratings. The Arx is equipped with a Multidirectional Impact Protection System. These helmets have an inner lining that is supposed to minimize rotational force, believed to be a prime factor in traumatic brain injury, and reduce the amount of energy delivered to the head.

But whether a helmet with this system minimizes rotational force any better than a helmet without it is a matter of debate. Consumer Reports did not test that feature because it could not find a standard test for rotational force. It judged the Scott Arx Plus on the same features as it did for every other helmet in its tests.

The top-rated bike helmet for kids is the Bontrager Solstice Youth. At $40 it’s a Consumer Reports best buy. The helmets that were tested ranged from $12 to $220.