"Which Shoei helmet should I choose?" is a question we usually hear. It stems from several factors such as having too many attractive helmets to being unsure of how one would fit to budgetary concerns.
Let us go through each of these most common types.
FULL-FACE
The full-face helmet offers the best protection from accidents and the elements. But there are specialised ones for different roles, although some may blur the lines between them.
These are meant for high speed and extreme usage. As such, they offer the best level of protection possible with great aerodynamic properties, and usually lighter. However, they are meant to be tight fitting to avoid moving around at great speeds (we are talking 200km/h and above). These are usually flagship models and made of exotic materials including carbon fibre, Kevlar, thus the most expensive.
Of course, you can use one for sport-touring and everyday riding, but the tight fit may not be as comfortable as a sport-touring and urban helmet.
Examples: Shoei X-Spirit III, Shoei X-SPR Pro (not in Malaysia yet).
Premium sport-touring helmets generally utilise some of the same technologies i.e. features and/or materials of the race helmet, but designed for all-day comfort, regardless. Therefore, they are "roomier" than the full-on race/sport helmet, along with several other "daily" features such as built-in sunvisor (depending on manufacturer).
Example: Shoei GT-Air II
If sport-touring helmets are roomy, urban/general full-faces are even roomier and airier to suit everyday riding in traffic. Comfort and convenience are the main criterias here. They are also suited for sport-touring.
Examples: Shoei Z-7, Shoei NXR2
MODULAR
As it is, some riders love modular helmets as they combine the protection of a full-face with the chinbar and faceshield down, and convenience of a jet-type (open-face) helmet with the chinbar and faceshield up (drinking water, talking to others at stops). It is thus chosen by touring and urban riders alike.
Example: Shoei Neotec II
JET/OPEN-FACE
The traditional helmet, jet-type helmets offer the best air flow and convenience for the daily commute. Touring riders who sit behind a large motorcycle windscreen may also consider these as the windscreen restricts cooling air.
There are stylistic jet-type helmets, too, of course, such as the Shoei J.O which is a great fit for classic bike, cruiser, retro and scooter riders.
Examples: Shoei J-Cruise II, Shoei J.O
ADVENTURE/DUAL-SPORT
The adventure helmet combines the features of the sport-touring and off-road helmets, thus they are suited for touring as well as for off-road riding on dual-sport motorcycles. Some allow the rider to remove the faceshield to fit off-road goggles. Some let the rider remove the peak and turn it into a sport-touring helmet. Some are even modular. Premium adventure helmets are usually lighter than their full sport-touring counterparts.
Example: Shoei Hornet ADV
OFF-ROAD
Off-road helmets feature prominent peaks to deflect debris from the rider's head and face. The large aperture allows for goggles. Off-road helmets are designed to provide maximum air flow as speeds are not that high on the trail or MX track compared to the road, hence they are noisy when used on the road - giving rise to the adventure helmet. Off-road helmets are also the lightest next to the jet-type to go easy on the wearer's neck.
Example: Shoei VFX-WR
CONCLUSION
Making the choice or choices is not as daunting as one can see above. The main criteria always comes down to "what do you want to use it for?" For example: Racetracks will not allow modular helmets, although they are technically full-face helmets. Similarly, you would not want to wear a road racing helmet while riding off-road.