What is the difference between city (urban) and mountain bike helmets? Is there any substantial difference between city (on the left) and mountain bike helmets (just examples)?




I understand that cycling in mountains is different in terms of risks from city commuting, however, my impression is that the safety standards do not distinguish the two.

In my case, I am looking for a helmet for city commuting. Can one say that a city helmet is provably safer in this case? What are its advantages and disadvantages?
In my impression the differences are:


Look: as a commuter/city biker you don't want to appear as colourful weirdo / stick out in the supermarket. The colours are therefore more casual. (I actually heard the industry believes one of the main reasons people don't wear helmets is their looks, and invested into designing them like beanies; I myself believe they are compared to scooter helmets unpractical - you cannot store them on the bike and have to carry them around)
Ventilation: as commuting is not considered a sport, you're expected to sweat less and in need of less ventilation. Some commuter helmets have (similar to ski helmets) even closable vents. Bear in mind, outdoor sport is biased towards nice weather. Commuting is done in any season. Probably many sport cyclists just skip rain cycling, where a commuter doesn't want to compromise safety (helmet) and a dry head (hat).


All studies concerning safety and protection don't indicate a difference. But some reports point out that the (European) safety standard for bike helmets has its flaws: only central hit from the top is tested, no side coverage tests, impact corresponds to a fall from 1.5m height (5 feet) and speed somewhere around 20 km/h (12.5 mph). The report claimed that side impact and higher speed impacts are where high price helmets and low price helmets differ, but it didn't get more specific. I am not aware of a safety difference as function of target user group.

EDIT: It appears the report I meant is not online anymore. There are traces of it here https://erfolgsebook.de/teuer-oder-billig-fahrradhelme-wiso-zdf/ (it was German public television who're not allowed to keep their material online).