Helmet ventilation question.

[Rsmith]

I have a Zamp flip up full face with vents in the chin bar and on the top and back of the helmet. The two vents in the front on the top are open into the helmet (two small holes were cut through the styrofoam by the manufacturer) to allow air flow into the helmet lining. However the rear vent hole has no opening thru the styrofoam into the helmet area at all.

My question is this. Do you think that was a manufacturer defect since the rear vent doesn't open up into the helmet, and would I be safe in opening that area up just enough to allow some air to circulate into the lining?

Also, since I have the LT with the large windshield will that prevent even the best ventilating helmet from getting enough air to cool off the top of my head. Riding in 80+ degree weather even at speed makes my head very hot.

Any advise would be appreciated on this. I'ts been about 30 years since I had a helmet (returning rider) and just wondered how some of the better brand helmets worked from a ventilation perspective.

Thanks,
Rob

[Takahashi]

I know that at least some helmet manufacturers (like mine) put vents on but then don't put holes in the padding. If you make your own holes I have no idea what happens but it won't be the same helmet they tested for DOT and Snell certs.

[zedx11]

there may be channels between the outer shell and the inner styrofoam. check out their site to see if that is the case.

[eidian]

Originally Posted by zedx11

there may be channels between the outer shell and the inner styrofoam. check out their site to see if that is the case.

+1

I have Shoei RF1000 and I can't see light through any of the holes in the front or back vents from the outside but when I look inside the helmet, there are two grooves cut into the styrofoam where the air flows through. I feel air flow when I open them so I know that it works.

[Il Burlone]

Originally Posted by eidian

+1

I have Shoei RF1000 and I can't see light through any of the holes in the front or back vents from the outside but when I look inside the helmet, there are two grooves cut into the styrofoam where the air flows through. I feel air flow when I open them so I know that it works.

Shoei RF1000 is one I was looking at, along with the Arai RX7 Corsair. Anyone know how the ventalation difference is between them. The tangible differences other than look and DOT and SNELL certification. Do they both breathe as well?

[BikerBeagle]

Originally Posted by Rsmith

I have a Zamp flip up full face with vents in the chin bar and on the top and back of the helmet. The two vents in the front on the top are open into the helmet (two small holes were cut through the styrofoam by the manufacturer) to allow air flow into the helmet lining. However the rear vent hole has no opening thru the styrofoam into the helmet area at all.

My question is this. Do you think that was a manufacturer defect since the rear vent doesn't open up into the helmet, and would I be safe in opening that area up just enough to allow some air to circulate into the lining?

The rear vent is an exhaust (using the vacuum of the air flow behind your helmet), not an intake; therefore, it doesn't need to have direct air flow. Its purpose is simply to pull the air out from between the liner and the outer shell. Between this and the 2 intake vents you have on the front top of your helmet, it is supposed to create a sort of 'evaporator effect' in the lining itself. (The intake vent in your chin bar is almost certainly an anti-fog deterrent for your visor and doesn't contibute much, if any, to this). Now, whether or not it all works the way it should (or well enough for you) is another topic altogether. Opinions on the effectivness of venting for any particular helmet are widely varied by individual.

Originally Posted by Rsmith

Also, since I have the LT with the large windshield will that prevent even the best ventilating helmet from getting enough air to cool off the top of my head. Riding in 80+ degree weather even at speed makes my head very hot.

Most helmet venting systems have a limit to their effectiveness no matter how much air is provided (after all, it's an evaporative effect ...not a water cooler or a wind tunnel). Certainly, more air = better efficiency, but there comes a time where the heat generated by head, internal, and ambient temperature exceed the ability of the venting to disperse it quickly enough. You will find this true in ANY FF helmet you purchase (and why there are several people who simply won't ride with FF helmets when the temperature exceeds 90F).

The best suggestion for you is to 1) ride without a face visor or 2) get yourself a DOT 3/4 helmet for higher temperature riding. Unlike the windshield of a car, the face visor on a FF helmet is not a factor in determining its impact rating. Both options basically sacrifice eye protection (so get some impact-resistant eyewear or the face shield for the 3/4) and wind noise for freeflow air.

[Rsmith]

Thanks for the excellent explanation Beagle. I remember back in the 70's I had a full face, and a 3/4 with a bubble shield when I rode my old CB 350. The full face didn't have vents back in those days and would often fog up really bad on cool mornings so I would usually wear the 3/4.

I also remember wearing a nice full face when I test rode the 900 at the dealership (borrowed) and I could actually feel the air flow across the top of my head during the test ride. But that was on the classic and not the LT which I now have, and of course a different helmet (brand).

I guess the real issue is with the ability of each helmet to vent effectively. I like the features of the Zamp but it doesn't vent well. At least this now gives me a good excuse to go helmet shopping.

[Zukdriver]

I use an Arai Profile and the ventilation is excellent. There are five vents on the front and top of the helmet and a large exhaust vent in the back. Arai's thinking is that it's more important to get the warm air out than in. It seems to work. Can't speak of the Shoei - never tried one. HJC is supposed to vent well but nowhere near as well as the Arai.

[Il Burlone]

Originally Posted by BikerBeagle

The intake vent in your chin bar is almost certainly an anti-fog deterrent for your visor and doesn't contibute much, if any, to this.

Are most intakes on a helmet going to serve the purose, how well do those leech out moisture. I don't know whether to get the breath guard for the arai or if it's a waste.

[BikerBeagle]

Originally Posted by MStephan

Are most intakes on a helmet going to serve the purose, how well do those leech out moisture. I don't know whether to get the breath guard for the arai or if it's a waste.

I'm sorry, I don't know the specific effectiveness of the breath guard that comes with the Arai, but I'd say -in general- any breath guard is better than no breath guard.

A breath guard accompanied with 'as directed' application of FogX should be sufficient to alleviate 98% of the situations you would ever likely encounter, excepting a small percentage for the most severe conditions.

[Il Burlone]

Originally Posted by BikerBeagle

I'm sorry, I don't know the specific effectiveness of the breath guard that comes with the Arai, but I'd say -in general- any breath guard is better than no breath guard.

A breath guard accompanied with 'as directed' application of FogX should be sufficient to alleviate 98% of the situations you would ever likely encounter, excepting a small percentage for the most severe conditions.

Thanks. Like you said any breath guard is better than no breath guard. I'll ask around on that one so I will probably just get one.