Interesting diagram shows the impact areas on crash-involved motorcycle helmets.

(Source: Dietmar Otte, Medizinische Hochschule Hannover, Abteilung Verkehrsunfallforschung, Germany.)

Note that 35% of all crashes showed major impact on the chin-bar area. This means that if you ride with an open-face helmet, you are accepting only 65% of the protection that could be available to your head.
If people ride with a shorty or half helmet, they are accepting only 39% of the protection they could obtain. They are literally throwing away 61% of the protection they would have had had they chosen a full-face helmet.

At Scooter Underground we always recommend a full face helmet as your main helmet, especially the one you may be using for daily commuting.

Full Helmet with Face Shield & Chin Guard

If you can afford only one helmet and your primary use is for commuting, the full helmet with face shield is a great choice.

PROS: Best level of protection. Face shield protects against the elements and bugs without the need for goggles or protective eyewear.
CONS: May be heavier/hotter/less comfortable. Hearing may be restricted.

Full Helmet with Face Shield – no chin guard

A good choice for an all around helmet but sacrifices protection to the chin and jaw

PROS: Good compromise of safety and comfort. Easy to talk and keep cool.
CONS: Vulnerable chin and jaw. These types of injurines are quite common Hearing may be restricted.

Full Helmet without Face Shield or Chin Guard

A good choice for an all around helmet but you must wear this with your eyeglasses, goggles, sunglasses, or other protective eyewear.

PROS: Good compromise of safety and comfort .Easy to talk and keep cool.
CONS: Must remember 2 things rather than one: Helmet and eyewear. Hearing may be restricted.

Half Helmets

Best as a “nice day” helmet or for urban cruising, but not recommended as your primary urban cruiser unless you can’t stand having your ears covered.

PROS: Cool (in more ways than one), light weight, does not restrict hearing.
CONS: Lowest level of protection, especially to the lower skull, cheeks, and front of the face. You must remember eye protection.

It’s great to have more than one helmet and it’s also wise to make sure it fits properly and is secured to your head with a convenient chin strap. If you are ever carrying a passenger, it’s great to have a spare helmet nearby – even if the sizing isn’t perfect, at least you’ve got something.

If you want a spare helmet, it’s often good to get something slightly larger that can accommodate something like a hat or a headband for cold weather riding.

Also, check to make sure your helmet choice is compatible with where you want to store it. For example, many scooters have under-seat storage but not all helmets will fit.