A Buyer's Guide
to Bicycle Helmets
The Two Minute Summary
- You always need a helmet wherever you ride. You can expect to crash in your next 4,500 miles of riding, or maybe much sooner than that!
- Even a low-speed fall on a bicycle trail can scramble your brains.
- Laws in 22 states and at least 201 localities require helmets, although few cover adults.
- Make sure your helmet fits to get all the protection you are paying for. A good fit means level on your head, touching all around, comfortably snug but not tight. The helmet should not move more than about an inch in any direction, and must not pull off no matter how hard you try.
- Rear stabilizers do not substitute for careful strap adjustment.
- Pick white or a bright color for visibility.
- Common sense tells you to avoid a helmet with snag points sticking out, a squared-off shell, inadequate vents, excessive vents, an extreme "aero" shape, dark colors, thin straps, complicated adjustments or a rigid visor that could snag in a fall.
- Consumer Reports has some brand recommendations.
If you have six minutes, please read on!
Six Minutes More
Your brain is probably worth reading this!
The average careful bike rider may still crash about every 4,500 miles. Head injuries cause 75% of our nearly 700 annual bicycle deaths. Medical research shows that bike helmets reduce or prevent most of cyclists' head injuries. And helmets may be required by law in your area.
Need One? Yes!!
A helmet reduces the peak energy of a sharp impact. This requires a layer of stiff foam to cushion the blow. Most bicycle helmets do this with crushable expanded polystyrene (EPS), the white picnic cooler foam. EPS works well, but when crushed it does not recover. A similar foam called expanded polypropylene (EPP) does recover, but is much less common. Another foam called EPU (expanded polyurethane) has a uniform cell structure and crushes without rebound, but is heavier than EPS and its manufacturing process is not environmentally friendly. Other foams and deformable plastic systems appearing that may offer promise. The spongy foam pads inside a helmet are for comfort and fit, not for impact protection
How Does a Helmet Work?
The helmet must stay on your head even when you hit more than once--usually a car first, and then the road, or perhaps several trees on a mountainside. So it needs a strong strap and buckle. The helmet should sit level on your head and cover as much as possible. Above all, with the strap fastened you should not be able to get the helmet off your head by any combination of pulling or twisting. If it comes off or slips enough to leave large areas of your head unprotected, adjust the straps again or try another helmet. Keep the strap comfortably snug when riding. The straps hold your helmet on, not the rear stabilizer.
Most bike helmets are made of EPS foam with a thin plastic shell. The shell helps the helmet skid easily on rough pavement to avoid jerking your neck. The shell also holds the foam together after the first impact. Some excellent helmets are made by molding foam in the shell rather than adding the shell later.
What Type do I Need?
Beware of gimmicks. You want a smoothly rounded outer shell, with no sharp ribs or snag points. Excessive vents mean less foam contacting your head, and that could concentrate force on one point. "Aero" helmets are not noticeably faster, and in a crash the "tail" could snag or knock the helmet aside. Skinny straps are less comfortable. Dark helmets are hard for motorists to see. Rigid visors can snag or shatter in a fall. Helmet standards do not address these problems--it's up to you!
A sticker inside the helmet tells what standard it meets. Helmets made for the U.S. must meet the US Consumer Product Safety Commission standard, so look for a CPSC sticker. ASTM's F1447 standard is identical. Snell's B-95 standard is tougher but seldom used.
Fit is not certified by any standard, so test that on your own head. Visors are not tested for shattering or snagging in a fall, so you are on your own there.
Coolness, ventilation, fit and sweat control are the most critical comfort needs. Air flow over the head determines coolness, and larger front vents provide better air flow. Most current helmets have adequate cooling for most riders. Sweat control can require a brow pad or separate sweatband. A snug fit with no pressure points ensures comfort and correct position on the head when you crash. Weight is not an issue with today's bicycle helmets.
Some head shapes require more fiddling with fitting pads and straps. Extra small heads may need thick fitting pads. Extra large heads require an XXL helmet. Ponytail ports can improve fit for those with long hair. Bald riders may want to avoid helmets with big top vents to prevent funny tan lines.
We always recommend checking out the latest Consumer Reports article, but they can't cover very many of the available brands and models, and their articles go out of date.
How to Buy
We have a review up on helmets for the current season. It has no impact ratings, but our limited testing has shown that most helmets have about the same impact protection regardless of price.
When you pick up a helmet, look first for a CPSC sticker inside and a smooth, well-rounded shell with a bright color outside. Put it on, adjust the pads and straps or the one-size-fits-all head ring, and then try hard to tear it off. Look for vents and sweat control. Helmets sell in bike shops from $30 up, or in discount stores for less. A good shop helps with fitting, and fit is important for safety. The $10 discount helmet can be equally protective if you take the time to fit it carefully, and for another $10 you get easier fitting. Helmets are cheap now, and are seldom on sale, so don't wait for a sale price. Many of us bought our helmets after a crash. You can be smarter than that.
Check out our pamphlet on child helmets.
Replace any helmet if you crash. Impact crushes some of the foam, although the damage may not be visible. Helmets work so well that you need to examine them for marks or dents to know if you hit. Most manufacturers recommend replacement after five years. We think that depends on usage, and many helmets given reasonable care are good for longer than that. But if your helmet was made before 1990, it's time to replace it. Replace the buckle if it cracks or a piece breaks off. No one requires you to replace your helmet, so give it some individual thought.
When Must I Replace a Helmet?
The ASTM standards for biking and inline skating are identical. But aggressive skating and skateboard helmets have their own ASTM standard, designed for multiple hits with lesser impact severity. Those helmets may not handle bicycle impacts. Do not use a skate helmet for bicycling unless it has a CPSC sticker certifying that it meets the CPSC bicycle helmet standard!
Bike Helmets for Skating?
Warning: Children must remove helmets before climbing on playground
equipment or trees, where a helmet can snag and choke them. Here is
more information on that problem.
Warning! No Helmets on Playgrounds!
The Bicycle Helmet Safety Institute
BHSI is the helmet advocacy program of the Washington Area Bicyclist Association. Our volunteers provide helmet information and work on the ASTM national helmet standard committee. In 1983 we published in Bicycling Magazine the first bicycle helmet article including actual lab test results (based on testing done for us by the Snell Foundation). We are funded by consumer donations of about $11,000 a year. We do not accept funds from manufacturers or anyone involved in helmet sales.
BHSI is located at 4611 Seventh Street South, Arlington, VA 22204-1419, tel. 703-486-0100. Our Web server where you found this page is at www.helmets.org. Our email address is email@example.com.
Our parent organization (WABA) is a local non-profit founded in 1972 to improve bicycling conditions in the Washington, DC area and encourage the use of bicycles for transportation. BHSI is an outgrowth of the WABA Helmet Committee that began ride testing helmets in 1974. WABA has a Web page at www.waba.org.
This pamphlet was produced with donations from those who read it earlier. We welcome your tax-deductible donation to make it available to the next rider or parent who will need it. Checks can be made payable to WABA/BHSI. Thanks!
Copyright 2014 by the Bicycle Helmet Safety Institute
A program of the Washington Area Bicyclist Association
Illustrations by Nancy Olds
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This page was last revised on: January 1, 2014.