Difference between MTB and Road Helmets?

[JQ]

I'm in the process of deciding on a new helmet. What's the difference between an MTB and Road specific helmet?

The majority of my cycling is commuting to work on road - 1hr per day 4 days per week on average. However I also do a reasonable amount of off-road, generally cross-country stuff, Marin Trail, 7Staines etc. But I'm also doing more recreational road biking now also. The vast majority of my time is now spent on tarmac.

Ideally I want something that covers all bases and just wondered if there were genuine functional differnces in the helmets or whether it was all just marketing. Top of the list currently is a Giro Atmos which I can pick up for around £77.

[Engineer1]

Style, airflow and aerodynamics.

[Smartboy]

I have an old Specialized S-Works helmet which I use on my main bike (carbon hard-tail XC bike).

I also have a road-bike for commuting and an occasional weekend road-ride. I'm not a fan of the road-bike style, so still wear my MTB baggies, MTB helmet and my MTB SPD shoes and SPD pedals... think I've broken quite a few of the 'rules' there!!!

I guess I could remove the peak to get it looking a little more 'road' style, but I'm not too bothered.

Guess it depends on how style-concious you are, what level of riding you do, and what your mates are like who you ride with... will your roadie mates take the mick if you turn up with a MTB lid or vice-versa

[shouldbworking]

Road specific ones will generally not have a peak so that you can still see where you are going without having to crane your neck all the wap up when riding a road bike.

Some mtb ones offer more protection to the back of the head.

[Vladimir]

My old Specialized 2D was designed for both; I just took the peak off for road riding (where your head tends to be lower). Just bought a road biased Giro Atmos despite riding almost all MTB stuff.

TBH I reckon its roadies that need more protection; harder roads, higher speeds, worse brakes!