Summary: Descriptions of typical road, mountain, commuter, skate, BMX, downhill racing, chrono, youth, toddler and women's helmets.
The original bike helmets were made for bicycling on roads and road racing. As they have evolved, they mostly had an
elongated shape, always with vents, and are usually made with EPS foam covered by a thin plastic shell. These are the
most-used helmets in the world, and millions of them are sold every year.
The term coined by Bell in 2004 when they introduced their Metro model. It has come to mean a helmet with a rounded
shape, rather than the elongated road style. Has vents, and is usually made with EPS foam covered by a thin plastic
shell. It sometimes has accessories such as mirrors, winter ear flaps and rear blinkers that are useful for
Enduro helmets appeared in many lines for 2015 and continue to expand. They are designed for enduro racing--stage
races with riders racing the clock over timed downhill courses. Between downhill stages, the racers have to climb to get
to the next course, so there is a premium on ventilation and light weight, and riders are sometimes willing to compromise
on protection to get that. Some manufacturers just designate road models as their enduro models, but the form generally
resembles a downhill mountain bike racing helmet, often with a chinbar. The level of protection needed would seem to call
for downhill helmets, but enduro models may or may not meet the more demanding ASTM F1952 downhill mountain bike racing
Usually a small or medium road or mountain helmet, designed for riders from about 10 to 15. Graphics usually reflect
youthful themes. Has vents and is usually made with EPS foam covered by a thin plastic shell.
For children between the ages of 5 and 10. Can be just a smaller youth model, resembling a road helmet, or can have a
rounder shape like a toddler helmet. Tested under the CPSC standard with exactly the same headform weight and drops as an
adult helmet. The age categories are blurred by head size variations, and if the helmet fits the head the age tag can be
Made for very young children, usually under the age of five. Typically round and smooth. Extra rear coverage has
always been part of toddler helmets, and is required to pass the CPSC standard if the helmet is designed for children
under the age of 5. If the foam is thick in the rear, the child should be supported by a pillow behind the back if
transported in a trailer or high-backed child seat to avoid forcing the head forward and down. Tested under the CPSC
standard with exactly the same headform weight and drops as an adult helmet.
A helmet designed for a woman must have a place for long hair, usually a pony tail port. That should be a channel in the foam in the rear. There were a few such helmets in the early 1990's, but they disappeared after men stopped wearing their hair long. Today the term denotes the same helmet design sold to men, but in a medium size and with pastel graphics or perhaps a flower or two.
Giro's 2013 catalog was unusually frank about women's helmets: "What about fit for women? - While it is obvious that
anatomical differences between men and women can dictate different patterning and fit for many items worn on the body,
the head and skull are somewhat unique. When measuring men and women's heads, there is no significant difference in the
skull shape, location of skull features or the scale of the ears, eyes and nose between men and women." That of course
was written by a person without a pony tail.
The aero road is a road helmet made more aerodynamic, often by covering the vents. Some have adjustable vents, or use
They are used by pros in some races, but abandoned for stages where ventilation becomes critical. They will not improve the average road rider's performance very much since the average male reportedly rides at 15.6 mph (25 kph) and the average female rides at 13.4 mph (21 kph) according to uploads to Strava. They are not as slick as a chrono time trial helmet, but some riders might want one for the image, and some aero road helmets have the rounder, smoother profile that we recommend.
A lightweight motorcycle-style helmet, usually with a chinbar to give some facial protection. Used in off-road
downhill races, usually on wooded terrain with rough courses. Generally has vents, and is made of EPS foam with either a
thin plastic shell or a thicker one made of either plastic or a composite material such as fiberglass or carbon fiber.
One of the few choices for road riders who want facial protection but must have vents. The best are certified to the ASTM
F1952 Downhill Racing Helmet standard.
Skate helmets began as round smooth hard shell helmets in the 1970's, and skateboarders cling to that shape still. It
is in fact the best shape for hitting pavement at high speed. The shell is usually hard ABS plastic, and the interior
foam can be EPS, EPP or a variation of those types. Skate helmets were once made with a squishy butyl nitrile foam that
works well in lesser impacts but cannot handle the energy of a full hit from a bicycle, or even some skateboard crashes.
Some are still made that way. Skate helmets traditionally have very small round vents that do not move enough air for
comfortable bicycle riding. There is an ASTM F 1492 Skateboard helmet standard, but most skate helmets now in the US
market are certified only to the CPSC bicycle helmet standard. The best are dual certified to
The Consumer Product Safety Commission has a very useful chart of helmets matched to various activities on their website.