Hello grumpier.mike and All,

I will have an LG P-09 helmet ordered that should be delivered in a couple of days to experiment on.



I noted in the pictures that the visor is supported in the center with a ventilation gap all around the lens.

If the vent gap is of any size it could be the source of drag and should be sealed for better aerodynamics.

I will add my own different custom visor sealed on the edges with variable vents in the center of the lens itself.

It might be worth considering sealing the standard visor around the edges with tape - the tape overlapping the gap need not stick to the helmet if it fits very closely so the flip up feature would still operate. Depending on how hot that makes your face you might want to make a couple of small holes in the visor adjacent to your forehead.

One way to make a nice clean hole in polycarbonate sheet plastic is to heat a piece of small diameter copper tube (as desired 1/4 inch diameter to 1/2 inch diameter) with a blowtorch and carefully push it through the plastic. Makes a nice clean hole you and can clean up the sharp edges with a Dremel or just a small piece of sandpaper.

I think the drag gains would be very small but every little bit counts.

Cheers,

Neal

+1 mph Faster

I'd be curious to see how this looks. I have the P-09 as well. I thought it was the fact that the visor was sealed that reduce its aero savings? I may not recall that correctly but thought it was something Mark COTE said from their testing on the McLarens?

Hello Tony5 and All,

Good point ...... you could be right ..... as noted by how different helmets work for different people .......... the airflow around the head position is affected by so many variables it is difficult to generalize.

Often leaks and gaps that disrupt the general shape being implemented are causing more drag than the smooth basic shape design ...... unless the leak or gap or vortex generator is energizing the surface flow to help maintain laminar flow ..... as you note that could happen in the case of the visor ..... but I doubt it.

Cheers,

Neal

+1 mph Faster

Yes, because you're in essence "completing" the cylinder and the air wants to separate from that cylinder at the apex on both sides. Beyond a flat plate, a cylinder is about the worst shape you can present to the wind. Just because a helmet looks like it has an airfoil shape with a shield doesn't mean it actually is an airfoil shape designed for laminar flow. Notice the fastest helmets, the P09 and McClaren, both test faster without the shields - both are designed to have air flow through them, not just around them.

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Jim Manton / ERO Sports

always appreciate your feedback Jim. Thanks.

I don't understand why they don't make the curve of the shield into a shape other than a circle so the leading edge of the helmet is more airfoil shaped. I can't image how my big old nose and hairy eyebrows could possibly have a Cd much lower than that of a flat plate, especially at any yaw angle greater than 2 degrees.

I was actually mistaken. It tested the best at with plug and visor at 5 and 15 degrees. At 10 degrees it tested the 3rd best.

Here are are the differences from my baseline in grams

…………………………………….5 10 15

Plug and Sunglasses……….-40 -140 -109

No Plug and Sunglasses… -120 -120 -140

No Plug and Visor……………-35 -40 -95
Plug and Visor………………-152 -82 -140

Thanks for that. No really, more confusion on the matter...It always come back to N=1 which is a tad depressing...Nice blog too. congrats on good race.

Thanks!

It really is unique to the person. I was surprised to see how bad my Rudy Project helmet was compared to others.

Knowing how many watts I saved from testing I wish I would I have done it years ago. Its definitely the best investment you can make.

For those interested I'll be posting a blog post later this week with some of my other results. Clothing, bottle and position changes.

I used mine in a race last Sunday. Was going to try the visor but it fell out as I was picking it up to put it on in T1! So I went with my sunglasses instead. It doesn't latch in very well at all and considering it's dubious aero advantage, I will be leaving the shield at home from now on. Otherwise the helmet was really nice, I found it a lot more comfortable then the Vorrtice.

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-Of course it's 'effing hard, it's IRONMAN!
Team ZOOT
ZOOT, QR, Garmin, HED Wheels, Zealios, FormSwim, Precision Hydration, Rudy Project

When you click it in you have to push the tab over to make it lock.
I was scared going back into transition to get my gear that someone would have knocked it off my bike breaking or scratching the shield. I raced 70.3 Fl with it last weekend and agree on how comfortable it is.

Ah, user error then, thanks! Still probably won't use it but it is a slick design.

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-Of course it's 'effing hard, it's IRONMAN!
Team ZOOT
ZOOT, QR, Garmin, HED Wheels, Zealios, FormSwim, Precision Hydration, Rudy Project

Hello ffmedic84 and All,

Thanks for posting your helmet data.


I received a medium helmet yesterday and using your data as an indicator will be adding my own version of a visor (sealed) and running it without the plug.

My head measures 23 in. (58.4cm) and the medium fits snug but comfortable ..... I will take it on a long ride soon to see how it fits over time.

As others previously mentioned I really like the ear flap feature and the very close fit of the helmet which seems to have the least frontal area of any helmet I own.

It makes my other helmets look fat.

Ideally I would like the P-09 without the tail .... more like a Bambino for riding with the head down.

Cheers,

Neal

+1 mph Faster

Wow those are some amazingly confusing numbers. I can't believe what a difference the there is. If I use the 9-10 grams is 1 watt, then there is up do an 11 watt difference for plug and visor options. I never would have thought the difference would/could be that much!

I was surprised too. We repeated some of the tests with the bigger gains and they all tested consistent.

for those that wear their helmets rotated back, how far back to you go? some of us have five or six heads instead of foreheads and if rotated back enough to get to back, a visor might say only come down to top of ones eyebrows :) this is how I wear mine when racing :|

Jeff,
I wear my helmet rotated way back and I had a problem at the Charlotte TT with the visor on my LG-09 pressing on my nostrils. I was surprised. I haven't raced with it again since, but I need to figure out a way to rotate it even more or to go without the visor ... Or trim it.

if I wore the med, the visor would not be an issue. the large is too big, wont stay where I want, just like the large selector. I was serious about the visor only reaching the top of my brows

PSA - not a reply to you.

The LG factory store in Newport, VT (middle of nowhere) had about 6 P-09s for $99. Only one large, a few small, and med. The large that they had was the white and blue, I think that they had S and M in both white/silver and Black. They also had tons of skin suits an other gear at pretty crazy prices.

Just bought a white/silver one in both medium and large. Thinking the medium will fit my 57 cm head the best but wanted to be sure.

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blog

just sent mine back. med too small, large too large and I am 57cm. my head shape just isn't right to fit their mold(not spherical on top)

I had the same issue - small too small and medium too big. Interestingly, my wife and I have the same size noggin (54 cm) and the small fits her fine.

Just got mine. Anyone having issues attaching the visor securely onto the helmet? I've tried doing so with force and also pushing the tab outwards but it still refuses to "click" in.

What works best for me is to push the clip all the way in and then push the tab into position. It should click in then.

Due to the plastic nature of the parts involved, I wouldn't use any tools, such as a screw driver, etc. to minimize the opportunity for breakage.

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Team Kiwami
Instagram

I might be looking to sell mine Large color blue...

I tried a couple times in the trainer and I am not too happy with half of my ears off...

make me an offer and it is yours :)

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The entire event (IM) is like "death by 1000 cuts" and the best race is minimizing all those cuts and losing less blood than the other guy. - Dev