Aero Drag/Power

[daveryanwyoming]

.... Are you suggesting that there was little measurable difference in drag between the helmets, but some were noisier than others?...

I'll take a very safe guess here and say that Steve was using the expression "in the noise" to refer to meaningless differences in the measurable data, not actual acoustic noise. It's a common term in engineering and data analysis circles and has nothing to do with what you hear when you wear your helmet....

-Dave

 

[Alex Simmons]

I have seen quite a large difference in CdA between different aero helmets on Jayson (the fellow about to attempt the age category hour record this coming weekend).

Yet I recall Andy Coggan has before said he hasn't seen marked differences between hats he's tested.

I would suggest it depends a lot on the individual rider and their position.

 

[acoggan]

I have seen quite a large difference in CdA between different aero helmets on Jayson (the fellow about to attempt the age category hour record this coming weekend).

Yet I recall Andy Coggan has before said he hasn't seen marked differences between hats he's tested.

I would suggest it depends a lot on the individual rider and their position.

I think you've nailed it with the last bit. If your head is somewhat up in the air, then the right long-tailed aero helmet can make a big difference. OTOH, if your head is lower/more in line with your torso, then it seems that most any aero helmet works pretty well.

 

[frenchyge]

Anyone areo tested an integrated windscreen vs. regular glasses or a bare face?

What about the dimply new LG Superleggera helmet?

 

[Steve_B]

If your head is somewhat up in the air, then the right long-tailed aero helmet can make a big difference. OTOH, if your head is lower/more in line with your torso, then it seems that most any aero helmet works pretty well.

That's pretty much what was going on with me. My head is about as inline with my torso as I can get and still be able to see up the road. However, due to an oversight on my part, the way the straps on my LAS helmet were set, the tip of the tail was a bit higher than I would like and was not conforming to my back well and not filling in the gap between my head and my back as I was hoping for. So one of the helmets I tried was the Louis Garneau Superleggera and this conformed to my back quite well, filled in the gap, and was actually a bit lower vertically (possibly smaller frontal area). We were wondering if we would see a discernible difference in drag and there really wasn't. We tried I think 3 or 4 other helmets and the differences were imperceptible - conclusion: for me, in that riding position, which aero helmet I used mattered little. YMMV.

BTW - Dave is right. "In the noise" just means "undetectable differences". Nothing to do with wind noise.

Re: visor vs. bare face vs. sunglasses - My LAS has a visor whereas some of the helmets I tried had no visor, so I rode those with a "bare face". As I said before, no detectable difference overall and if I couldn't see a difference in helmets, I suspect the difference with and without a visor would be equally hard to detect. I actually prefer a visor but that's me. At least it isn't hurting me to use it.

 

[frenchyge]

I rode a visor for the first time last night on my Superleggera, and I really liked the function of it as well. It seems like it should be more aero, but I don't doubt that any difference is imperceptibly small in the big picture.

I can imagine that the cooling opportunity is lower with a visor compared to bare face + glasses, but it's not warm enough here to worry about that yet.