What kind of riding will you be doing? Cyclists who race may prioritize weight and aerodynamics above price and comfort considerations because they are looking for speed. However, riders who sometimes go off-road with their bikes will want a helmet that provides more protection for the back of the head.
How big is your head? Helmet sizes are not consistent across brands (if you wear a large with one company, you may be a medium in a different brand), so measure your head before trying on helmets and certainly before purchasing one online. Head shape is also a factor, so even if your head is within a helmet's recommended measurements, it still might not be the right fit for you. Visit manufacturers' websites to check sizing charts.
What's your hairstyle? Hair thickness (or lack of hair) can also be the difference between a great fit in one size and a slightly uncomfortable fit in another. Bald riders and riders with close-cropped hair may want helmets that feature extra padding so that the interior of the helmet doesn't wear on the scalp. Riders with long hair should consider some of the helmets aimed at the women's market for their ponytail-friendly designs.
Which seasons do you ride? Climate is another important consideration to note when shopping for a new helmet. If you often ride in hot weather or in a sunny climate, you're probably best off finding a helmet with excellent ventilation so your head can help regulate optimum body temperature while riding. If you live in a rainy locale, you might seek out a helmet with an optional rain cover or the ability to fit a cap underneath. Winter riders should try on new helmets while wearing knit caps or other insulating hats to make sure the helmet won't be too tight in the colder months.
Get help when measuring your head. Finding the right fit for a cycling helmet can be tricky, as each manufacturer has its own size categories. Ask a friend or cycling partner to help you measure your head before you buy.
Try on several brands. Unlike shoes and other sports accessories, helmets don't become more comfortable over time. How it feels when you put it on the first day is probably how it will feel until it needs to be replaced. So if it's not comfortable the first time, try a different brand.
Helmets don't last forever. Manufacturers generally recommend replacing your helmet every two years. Helmets should also be replaced after every crash, whether they appear damaged or not.
Try out the adjustment system. Most helmets on the market today feature adjustment systems (sometimes called fit systems or retention systems) the wearer can tweak using a knob or dial located at the back of the helmet. These systems work quite well, but riders may want to try a few in person.
For children's helmets, get their input. Parents report greater success in getting kids to wear the helmets when the children are allowed to pick out the color and style on their own.
Ask about store return policies. Fit comfort is vital when buying a bicycle helmet, but you may not know if the helmet is really comfortable until you're on the road. Ask the salesperson about their return policy before you buy a helmet.