Does anyone use a MX helmet for downhill riding, I can get an o’neal 812 for a really good price, but don’t know if it will be a bit overkill?

Any thoughts?

Yes I have and for bmx,

I found it a little heavy and little ventilation but got used to it.

Really is worth trying on to check you are ok with it.

depends on the weight really. and how much you will be using it. if its pretty light for a mx helmet. and your not going to be wearing it all day then should be ok……. but i would just get the no fear optimal 2 off crc if you have a big head thay might have your size and are currently reduced for £150 to £50

Does it look much bigger/bulkier than a DH helmet?

I used to use one a few years back. Twas ok for the most part, just a bit hot sometimes.

Of course, there is also the argument that they don’t protect as well as a bike helmet at bike speeds.

I’ve just changed my 661 evolution for a 661 flight , it is a little warmer but not much. How much of an issue is it likely to be? I’m rarely wearing the lid for more than 6-7 minutes at a time before an uplift/pushup so don’t get super sweaty.

Does it look much bigger/bulkier than a DH helmet?

Depends on brand, A few i’ve seen yes.

If you a big chap, its not going to matter and remember all helmet look stupid on.

“there is also the argument that they don’t protect as well as a bike helmet at bike speeds”

And the larger size will mean more whiplash effect in an impact where whiplash plays a part

I can’t rememeber the full argument/reasoning
TJ must have had something to do with it?

The only people I know who do, ride a lot of MX as well.

http://www.racespec.co.uk have a few Troy Lee ones going cheapish.
I would get a downhill helmet motobike ones are too heavy in general.Also you would tend to move around more on a cycle.I ride both but would never use a motorbike helmet on cycle.Did try it once an Arai not great and as said before very hot.

At the moment I have been using a MX helmet but when I buy a new one I will go back to a bike specific model.

I have read that MX helmets are tested to much higher speeds than bike helmets. I theory you could be using an MX helmet for desert racing at 80mph+ and it’s designed to withstand such an impact at the determent of slower speeds that you would encounter at DH speeds.
SO in theory a bike helmet offer you more protection when hitting a rock at say 20mph.

As James said….I read an article arguing that MX helmets are made for bigger (harder/faster) offs and that Mtb specific have better protection at lower speeds (based of push bikes traveling at significantly lower speeds)

I’m shit at mx and alright at dh but ride both. Should I swap my helmets and wear the most appropriate one for the speed I am doing?

😕 😉

I don’t know the ins and outs but wouldn’t that make the MX ones safer overall?

Here is the article from Pink bike which I read

http://www.pinkbike.com/news/DH-Helmets-vs-Motocross-Helmets-Which-Is-Safer.html

I would think so like ads678 says.Motorbike helmets are made for all speeds.You see down the Forest of Dean people having get offs helmets often cracked in front totally.In 10 years of MX racing never saw MX helmets that bad.Did see alot of get offs people suffering alot more than there helmets ever did.

had a Troy Lee SE mx lid – okay but heavy and little ventilation, D2 was a lot better.

My mx lid is lighter than more than a few bike lids.

I do. But I dont do loads of DH’ing, just a few uplift days and races.
I also rode all day in the Alps with it for a week, it was fine. Seeing as I already had it for the motorbike and dont use it much anymore, thought I might as well for the pushbike. Its 1100g, so not much heavier than a pushbike one, but hasnt got so much ventilation.

A lot of people reckon they’re better- tested to higher standards etc, capable of withstanding greater impacts and tested as such. The pushbike CEN is pretty undemanding after all.

Not really convinced myself, they’re designed with different agendas in mind. The venting alone is a big deal- keeping cool and comfortable is good primary safety, helps you avoid crashing in the first place!

But DH helmets are generally lighter (comparing like for like) and can also be “softer”- both quite a big deal in terms of injury reduction. Weight obviously puts more strain on the c-spine but also increases dwell time of the impact forces, whereas a less resistant helmet will reduce the forces on the brain since it decelerates slower- up til the point that it’s overwhelmed.

One other thing to remember is that a helmet that never cracks, crushes or otherwise breaks is too strong- it’s sacrificial protection. So seeing a helmet crack or break isn’t automatically a worry, it just means it’s laid down its life to protect yours. If it happens too easily, then that’s a problem.

The venting alone swings it for me but tbh if I had a moto-x helmet I wouldn’t be against using it, I just wouldn’t choose to buy one over a dh helmet.

MX lids are designed for use at higher speeds and as a rule have stiffer foam to compensate. This means that at the slower speeds of MTB they are less able to absorb the energy from the impact which means more is transferred to the head and so to the brain resulting in a greater chance of brain injury.

I read a good article about stiffer helmets in motorsports which explains it in more detail (I’ll try to find it later), there is a new way of thinking that helmets should be larger and be lined with a softer foam to absorb more of the impact so less energy is transferred to the brain whereas old thinking was a stiffer helmet protected better (from punctures, helmet cracking). As said above, helmets are supposed to break so that they absorb the impact. I would not be worried that you have seen lids crack and break – that is what they are supposed to do.

I believe Dirt also wrote about it.

It’s a bit different for the top Pro riders as they’re clocking much higher speeds than you or I but the general consensus is to pick a helmet that has been designed for the sport you’re doing.

Tom KP

An argument? On here? About helmets?

Well I never!

Fwiw, I tried one a few years ago (a fox one if memory serves) and it was very poorly vented, got hot v quickly. Troy lee d2 is much better.

Found it
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