The racy good looks of today's bicycle helmets mask a serious purpose: protecting their wearers from head injuries and even death.
How we tested bike helmets
To see how well helmets do their job, we put adult and youth models through an impact test using an apparatus that drops them at about 11 or 14 mph onto differently shaped anvils.
We used an electronic sensor inside a dummy metal head to detect how much force would be transmitted to a rider's head in an accident. We also evaluated the helmets for ventilation, ease of use, fit adjustments, and other features.
What we found
All but two models absorbed the force of impact within the limit set by the current Consumer Product Safety Commission standard. The two, both multisport helmets that claim to be usable for other activities such as skateboarding (which was not tested), slightly exceeded that limit in at least two out of three drops. We have judged them Poor for impact absorption in our Ratings (available to subscribers).
Of all the adult helmets we tested, only one provided the necessary protection in our own more-stringent test, in which we dropped helmets on the anvils at about 2 mph faster. At $60, it is a CR Best Buy. Three other helmets that met the government standard but did not pass our higher velocity test are recommended. All four of those helmets earned high scores for ventilation, fit adjustments, ease of use, and weight.
Youth helmets are intended for children age 5 or older. Of the youth helmets we tested, only one model is recommended, (see Ratings, available to subscribers), scoring the highest marks for impact absorption by passing our own more-stringent test.
Among children, bicycling injuries are the leading cause of recreational-sports injuries treated in emergency departments. (See the Bike safety.) A bike helmet can not only save a life, but it can also prevent or lessen the severity of brain injury during a bicycle crash. Nearly half of children 14 and under who are hospitalized for bicycle-related injuries receive a traumatic brain injury diagnosis.
Although almost any bike helmet is better than none in an accident, we believe that the models we have judged Very Good for impact absorption should provide significantly better protection.
How to get a good fit
A good fit is crucial so that in the case of an accident, the helmet remains in place and protects the head. Straps must be snug and the helmet positioned correctly. Once it's properly adjusted, only minor adjustments are likely to be necessary thereafter. Some specifics:
The front of the helmet should be level and no more than one or two finger widths above the brow.
The helmet should fit snugly, with the head partially compressing the soft foam pads inside, even before the straps are tightened. Select the size that fits as closely as possible without being uncomfortably tight. Then use the sizing pads, if provided, to fine-tune the fit.
The straps should form a "V" under each ear.
The buckle should be centered under the chin, not to the side or along the jaw. The straps should be snug enough that the helmet is pulled down when the mouth is opened. If the helmet is tipped back or the straps are loose, it will not provide suitable protection in an accident.
Straps might shift over time. Periodically check the tension and the position of the straps. If the helmet shifts when pushed, take the slack out of the chinstrap.
Head sizes and shapes vary. If a helmet can't be adjusted to stay on your head, try a different model. Try several sizes, models, and brands until you find the best fit.
Bike helmets should be replaced every five years, or sooner if the manufacturer recommends it, because the helmet's materials may deteriorate.If the helmet has been worn in an accident, replace it, even if it does not appear to be damaged.
If our rated models are not available, look for a label or sticker on the package that says the helmet meets the CPSC Bicycle Helmet standard.
Besides wearing a properly fitted bike helmet, follow these safe-riding tips to avoid accidents.
Get a good fit. Make sure that you can straddle the bike while off the seat and still have 1 or 2 inches of clearance for a road bike (3 to 4 inches for a mountain bike) to ensure that you are starting with the right size frame. Adjust the handlebars and the seat to fit the rider.
Check your equipment. Inflate tires properly and make sure the brakes work.
Make sure you're visible. Day or night, wear neon, fluorescent, or brightly colored clothing, and place reflectors, reflective tape, or a flashing light on your bike.
Control your bike. Carry items in a backpack or bicycle carrier, and not your hands. We also recommend that you keep both hands on the handlebars.
Watch for and avoid road hazards. Hazards can cause a crash, and include pot holes, sewer grates, broken glass, gravel, leaves, dogs, puddles, and more. If you can do so safely, alert riders behind you to upcoming hazards.
Avoid riding at night. It's harder for others to see you. If you must ride in the dark, use lights, wear reflective clothing, and make sure that your bike is equipped with reflectors in the front and back, on the pedals, and on the wheels or tires.