(NBC News) New safety ratings show some bike helmets are more protective than others, according to joint research from the Insurance Institute of Highway Safety and the Virginia Tech Helmet Lab.

Researchers used different types of helmets to replicate varied impact scenarios for bike crashes.

Of the 30 helmet models tested, 24 scored good or very good. Only four received the highest safety rating of five stars.

"You might assume that buying the most expensive helmet would give you a safer helmet and it isn't what we saw," said Steve Rowson with the Virginia Tech Helmet Lab.

The $200 Bontrager Ballista earned five stars, but so did the $75 specialized Chamonix.

What they, and other top-performing helmets had in common was multi-directional impact protection system, or MIPS. Road style helmets also performed better than urban style helmets.

Find the full list of helmet ratings here.