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Re: Giro Aerohead [Titanflexr] [ In reply to ]
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Exactly. If the screen is such a large part of the aerodynamics, how is it w/o the screen? I saw several riders ripping that screen off during the TT of the Giro in the rain. How does the helmet compare to the Specialized (that is neutral with or w/o screen).
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Re: Giro Aerohead [anthonypat] [ In reply to ]
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anthonypat wrote:
Jim,

Time savings in a 40TT w/ Aerohead V LG P09?

I think you need to read Jim's sig line. :)
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Re: Giro Aerohead [jeffp] [ In reply to ]
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jeffp wrote:


I also don't want a weighted yaw that includes 10 and 15 deg in it


You might be surprised how often those show up, even if you think you're fast. I was surprised.
Last edited by: trail: May 19, 16 15:43
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Re: Giro Aerohead [jeffp] [ In reply to ]
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jeffp wrote:
I also don't want a weighted yaw that includes 10 and 15 deg in it
ERO doesn't do weighted yaw. It's velodrome testing so basically 0deg with maybe a little bit of off zero thrown in in the corners and for an imperfect line.
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Re: Giro Aerohead [Jim@EROsports] [ In reply to ]
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Thanks. I literally just bought a new set of wheels, and my first thought was "what's the next piece of equipment am I going to obsess over until my budget refills?"

I think you just gave me the answer. :)
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Re: Giro Aerohead [lanierb] [ In reply to ]
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lanierb wrote:
jeffp wrote:
I also don't want a weighted yaw that includes 10 and 15 deg in it

ERO doesn't do weighted yaw. It's velodrome testing so basically 0deg with maybe a little bit of off zero thrown in in the corners and for an imperfect line.


Have you raced at Carson?

I get blown around there quite a bit at times with a front 808 or front disc. It's definitely not zero at times.

I think for ERO testing though they're more careful about shutting down some doors known to be related to some of the stronger drafts.

In any case, Jeffp was talking about the Giro-reported data, not ERO's.
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Re: Giro Aerohead [Jim@EROsports] [ In reply to ]
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Where is the technical aerodynamic breakthrough here? The shell portion of the helmet looks pretty unremarkable except for its overall size. Is the spiting of helmet into an upper and lower half the breakthrough? This allows the lower half and visor to be a continuous section?
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Re: Giro Aerohead [Jim@EROsports] [ In reply to ]
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I'll try to answer some of these questions, but the specific numbers belong to Giro, and are their's to make public.

  1. Shield or No Shield - I don't have the numbers in front of me, and we didn't test anything that went over the ears if you should choose to use sunglasses instead of the shield, but I would definitely use the helmet with the shield. I think Giro has mastered using a shield to "complete" the airfoil shape, which is why their helmets test faster with a shield than without. Plus, it's amazing how many people lift their heads to see under the frames of their sunglasses when out on the road, effectively raising their CdA.
  2. Position Influence & Design Breakthrough - I'm not exactly sure why this helmet works for so many people, but it doesn't seem to care about your position. I think it's partly due to some of the length being up front instead of using a longer tail. The "brow" of the helmet is more in front of you, so perhaps that negates the influence of the athlete's shoulders and back? It's also a very narrow helmet when seen from the front, though no one complained it was too narrow for their head.
  3. Shield Attachment - The magnets on this helmet are far stronger than previous helmets. The shield practically jumps off your hands when you put it in place. Keep in mind, I've only tested prototypes, the last one being two weeks ago.


Jim Manton / ERO Sports

Aero Tidbits posted on Instagram & Facebook
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Re: Giro Aerohead [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:
... Aerogeeks also quoted 15 watts over the Advantage 2. That number is absolutely correct, ...
Something is off...
15W yields ~1.5s/km, your testing indicates 5.5s/40km, or 0.14s/km, an order of magnitude less than the WT claims.

Has someone blown the WAD out of proportion?
The 16grams between A2 and Selector is ~2W, not 10w as claimed.

What am I missing?
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Re: Giro Aerohead [Nicko] [ In reply to ]
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exactly
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Re: Giro Aerohead [jeffp] [ In reply to ]
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i currently use a rudy wingspan. i'm assuming the giro a2 is better as the rudy just looks big on me. seems like it would be safe to assume this helmet should save me 10-15 watts from the rudy project...

at 200-300 that's not bad bang for your buck wattage in terms of equipment...

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Re: Giro Aerohead [ahhchon] [ In reply to ]
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ahhchon wrote:
i currently use a rudy wingspan. i'm assuming the giro a2 is better as the rudy just looks big on me. seems like it would be safe to assume this helmet should save me 10-15 watts from the rudy project...

at 200-300 that's not bad bang for your buck wattage in terms of equipment...

That's 10W at 50kph. The savings is roughly 1/2 that at 40kph, and 1/5 that at 30kph......it's not like the guy putting out 450W and the guy putting out 200W both save 10W.


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Re: Giro Aerohead [Jim@EROsports] [ In reply to ]
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Have anyone seen any information about sizes?
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Re: Giro Aerohead [bllx] [ In reply to ]
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OK, I'll be that guy, given the short tail and narrow frontal cross sectional area, how would this fare in a road position? I ride very low in the drops 30% of the time and sprint even lower
Last edited by: justkeepedaling: May 20, 16 4:57
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Re: Giro Aerohead [Jim@EROsports] [ In reply to ]
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Regarding the shield. How difficult would it be to take shield off and attach on top of helmet while riding? I'm thinking if it starts to rain and I need to remove the shield.
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Re: Giro Aerohead [trail] [ In reply to ]
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they may show up more frequently than I might like, but I still am not basing any of my choices upon that. foolish or not
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Re: Giro Aerohead [Jim@EROsports] [ In reply to ]
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Anyone care to break down the fine print for me on the Giro time/drag savings chart here: http://www.giro.com/...tm_campaign=homepage

I wouldn't come anywhere near putting out 400 watts over 40k, so how do I scale this to my own FTP? Could I use the wind average drag data deltas to equate it to my typical average power output and speed?

Also, is the baseline the original Advantage or the Advantage 2 helmet?

Best,
Chris
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Re: Giro Aerohead [Jim@EROsports] [ In reply to ]
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The website states the Ultimate features a TeXtreme carbon fiber shell – a stronger, stiffer material provides a slimmer shape with less frontal area. So is it actually narrower than the regular MIPS? Do you have any photos showing this?
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Re: Giro Aerohead [Titanflexr] [ In reply to ]
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Titanflexr wrote:
ahhchon wrote:
i currently use a rudy wingspan. i'm assuming the giro a2 is better as the rudy just looks big on me. seems like it would be safe to assume this helmet should save me 10-15 watts from the rudy project...

at 200-300 that's not bad bang for your buck wattage in terms of equipment...


That's 10W at 50kph. The savings is roughly 1/2 that at 40kph, and 1/5 that at 30kph......it's not like the guy putting out 450W and the guy putting out 200W both save 10W.

hmmm....

so here is another (possibly stupid) question. is a watt a watt a watt.. meaning.

assuming i ride 35kmp, it would be assumed that i would save 2.5 watts (roughly) with this helmet over the rudy project helmet.

2.5 watts might not seem like a lot for someone who's ftp is 250, but my ftp is about 200, seems like a 1% gain. assuming this, this 2.5 watts should go further for someone like me, who only weighs about 122lbs on race day, thus increasing my w/kg ratio higher than it would be for someone weighing 160lbs..

meaning, the helmet should have a more drastic effect for someone like me?

Catalyst Wheel Covers: Be faster and look great without sacrificing weight.

TOPO Footwear: use code TOPOTRAN20 for 20% off any order!
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Re: Giro Aerohead [TriTamp] [ In reply to ]
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TriTamp wrote:
Regarding the shield. How difficult would it be to take shield off and attach on top of helmet while riding? I'm thinking if it starts to rain and I need to remove the shield.

The person that shows up wearing a skin suit and this helmet for a road race may be planning on going into a breakaway.
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Re: Giro Aerohead [ahhchon] [ In reply to ]
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the watts for the rider listed are really a red herring. if the helmet reduces drag by X amount at Y speed, the things that are relevant are the X and the Y, not the Z power output as the rest of the rider/bike system might be assumed to remain unchanged. Give that the number posted make no sense on the Giro site, ie 1g reduction = 1w means they either need to correct their data or tel us why they are testing at 50 mph instead of 30mph(or whatever speed they are testing at , as it is not listed on the site) While Jim may be giving good insight, the giro site really looks like bad marketing spin that was not checked before uploading to the interwebs
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Re: Giro Aerohead [TriTamp] [ In reply to ]
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TriTamp wrote:
Regarding the shield. How difficult would it be to take shield off and attach on top of helmet while riding? I'm thinking if it starts to rain and I need to remove the shield.

It is not easy, but not impossible. The six magnets are quite strong. I would say it would be more difficult to remove the visor from the top of the helmet to use it again than to initially take it off.

Tony V
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Re: Giro Aerohead [Horchata] [ In reply to ]
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Horchata wrote:
Jim - in your experience so far, does this helmet test well for those that ride "head up" as well as those that tend to look down frequently as well, where tailed helmets tend to test worse?

When Giro did the testing they applied the 80-20 rule...80% looking up and 20% looking down to best replicate rider positions during a race. If that helps
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Re: Giro Aerohead [Bruizer] [ In reply to ]
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The pictures on the main page of the dummy is the Ultimate model. The ultimate has a 2% less surface area...


Tony V
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Re: Giro Aerohead [Tony5] [ In reply to ]
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Surface area or frontal area?
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