Hey all. I'm posting here instead of over at the Tri forum, as I think I'll get better opinions here. I'm in the market for a new helmet, specifically for Tri racing. That means aero. But I don't want a dedicated TT helmet. I want an aero roadie. My search essentially brought me to the Specialized Evade. That helmet seems to be the standard of road aero helmets, or at least in the top 3. But I rode today with my Bell Formula Mips, which was $50 beans, has a 5-star rating from VT, and fits so well that I don't even know I have it on. Keeps my head really cool in the desert heat. So I got to thinking: do I even need a new "aero" helmet? Will it make that much of a big diff in an Olympic Tri (which I aspire to)? And if so, what of the Bell Z20 Aero Mips? So less expensive, and I already like the brand. Any opinions on that model?

Thanks all!

If you ride in the Olympics, I'd bet your helmets would be sponsored and you'd wear what they gave you.

Until then .... if you are finishing second by a few seconds in race after race, go more aero. otherwise, get more fit.

If you have too much money buy five or six helmets and do a lot of back-to-back tests.

Otherwise, I wouldn't worry about the .05 aero improvement of anything but a TT helmet .... and when you really are high up in the ranks of Triathletes you will be hanging with top-tier triathletes who will likely know the best helmets and the best prices.

As far as I know, aero position on the bike is what really matters ... that is where the greatest gains and losses happen.

Also ... heat prostration tends to have s lowing effect ... before you pass out. Comfort can help you go faster.

TL;DR: I have no clue but I like to type things.

I second the above advice. My priorities:
- Safety (but they should all be certified)
- Comfort, not only size and good fit system, but venting.
- Another issue is I want the vents to be skewed enough so that I don't tan or burn my scalp from any sun angle, especially overhead when the sun is most intense. (My current helmet FAILS on this point.) If not, I need to wear a thin cap or put a white paper towel inside the helmet, which obscures venting. This is hot weather only, in cold it's gray out or the sun is low or I have a fleece hat on under the helmet.
- Large enough to fit a fleece hat underneath (with my size head, barely on current).
- Effective sun brim in front.
- Reasonably attractive appearance.
- Moderate price.
- Reasonably aero.

Do you need one? Of course not. Would it make a difference? Probably. In a shorter distance event like that difference would be small. What's your bike like? What's your current position like? Can you dial that in further? An aero helmet can make a pretty reasonable difference over a longer distance event (especially for the price compared to other upgrades). The aero gains are personal though and vary a lot from person to person. Without actually testing it yourself, it's very hard to say for sure.

Are your Olympic distance triathlons draft legal? If so, the helmet will make far less of a difference overall than sticking with a fast pack.

Thanks Maelochs! I was referring to Olympic-length triathlons, not the actual Olympics. I only do the short sprint tris right now, which typically have about a 9-mile ride. I'm not too concerned about an aero helmet for that. Nor will I ever be super competitive, so as to want to shave a few seconds wherever I can. To refine my question: does an "aero" helmet, or TT helmet, even matter for my needs?

Thank you. What do you use now, if I may inquire?

According to Silca, you have the potential to save up to 15W by upgrading to an aero helmet. So it is worthwhile if you are competitive.

https://silca.cc/blogs/silca/top-10-...0another%2015w.

The full on TT helmet is likely worth about 4 watts, compared to an aero road helmet. Over an Olympic distance bike segment, 40km, that translates to around 30 seconds. ( which will vary with the power and speed you’re already working with).

30 seconds can mean moving up or down a number of places.

Given that you’re buying a new helmet either way, and that modern tt helmets do a decent job cooling, I would definitely go with the full tt helmet.

I think that 15 watts is compared to a standard helmet. What I’ve seen the difference is smaller compared to the best aero road helmets.

Yes, aero road vs standard road helmet, which is what the OP currently wears. OP stated that they didn’t want a TT specific helmet.

So .... as with most questions, the definitive answer is "It depends."

All very good replies. I'm wondering what the real-world difference is between aero helmets. I saw the Bell Z20 and got interested because I use a Bell now and it fits wonderfully. I have never thought about it while riding. Great ventilation. 5-star VT rating. But will the Evade III at $300 offer that much more in aero quality over the $120 Bell Z20, to justify the price diff? These are the questions that keep me staring out the window late at night.

Aero enough.

For shorter tris, don’t forget to work on transition time. Lots of seconds are lost in T1 and T2.

Unless you can find some aero test data for both helmets then you will never know. But moving from a standard road helmet to an aero focused helmet like the Bell Z20 should give you a reasonable gain and I doubt spending more would really make a big difference.

LOL....I've only done two sprints so far. In my first, I think my T1 time was over 13 minutes! I lost the little ankle GPS device. In my second sprint, I got the time done to 3 minutes and I wasn't even trying to move quickly.

Keep us posted.

TTs should just issue stock equipment, same for all. Make it a human vs human competition.

Problem is some folks have Bell heads and some folks have Giro heads .... so everyone cannot wear the same helmet.

An evaluation of the ‘best’ aero helmets was done for you Here

An evaluation was done for exactly what you are looking for: https://www.cyclingnews.com/features...cling-helmets/

A Bell, the model of which I do not know, circa 2015. I had just fit clip-on aero bars but was still getting used to the transition between them and the flat bars, missed and went down at quick stop, hit hard enough to crack my 20+ year old helmet. Woke up to cop who just pulled up in car, said I was out about 30 seconds. I was ok, probably should have gone to hospital but head just felt a bit dull for a couple days, I took it easy during then and didn't bike, and was fine. Helmet definitely saved me from serious injury if not death. I ordered the Bell from Nashbar, $15 marked down from $50, good reviews, I've been quite happy with it except for the vents allowing the sun on my scalp. A couple years ago when a friend saw nice looking helmets at Costco marked down to $15, I checked fit (barely naked, no space for fleece hat) and bought one as a backup, I also like it because it's safety bright green. CPSC certified (do they have Snell certs any more?), but has same downside sun/vent issue.

My very first helmet, the Bell touring one with the smoked plastic brim, that was a lot of money early '80s, like $50-60 if I recall, they were pricey, but it was mandatory for a college class (they taught nothing it turns out, just had periodic rides, easy credit, but HEY, it got me started wearing a helmet ahead of the curve). After going down and seeing stars snowboarding, started wearing a helmet boarding and skiing, that old one which had worn loose by the '90s but fit perfect over a fleece hat or hood. I wear the current bike helmet for inline skating. If I'm sailing on a boat with a low boom, I wear the helmet, and a lot of sailing schools are now doing the same.

Now, helmets are common, and one need not spend that '80s price, especially in 2024 dollars, for a decent helmet. Simply one year old is gonna be at discount.

Y'know... I'll bet a cheap helmet, with the vents covered in aluminum tape, and if need be, NACA ducts cut in them for venting (notice below, not just cutting out that shape but the depressed inlet ramp), would be a lot more aero.

https://en.m.wikipedia.org/wiki/NACA_duct

I think you're being kind of generous. Not saying you're wrong. I believe your estimate could be accurate, but it depends on more than just switching out the helmet. Primarily, can you maintain that aero position through a majority of the 26 miles? Most of us age-groupers have a difficult time holding position for an hour plus, even in the best conditions. Start throwing in heat and exhaustion and our position goes to hell in a hurry.

I've gotten pretty strong on the bike in triathlon over the last few years. I'm age group competitive if only on the bike segment. But even on a relatively flat course like I did in Miami earlier this year, it's easy to drop your head when you start to get tired. Aero helmets get really un-aero really fast when out of position.

My personal take is just like the advice most triathletes get. The most aero gains is the position you can hold the longest. That would include the helmet. And if you can't hold the helmet the majority of the race, then a roadie is going to be every bit as good as an aero when you're looking at your pedals.

^ Head position clearly matters. If you tend to pedal head down, it argues for a shorter tail aero helmet.

So you need a helmet that works for you and your position on the bike. The right helmet for your fit and position is going to be an advantage, even if your position is less than ideal

if you’ve got a power meter you can figure out for yourself the best helmet for you using the Chung method. ( invented by a BF poster, who is likely your best source around here for aero info.) Only problem is you’ll have to buy or have access to the various helmet options to test.

Yeah, I think this is a good reason to go for an aero road helmet vs TT specific helmet. Aero road helmets are likely to be more forgiving in rider head position.

You can get more fit, improve your position, and use slipperier equipment. You can do all three: the rules allow it.

An improvement in aero of 0.05 may sound small but it's huge. That said, going from a "regular" road helmet to an appropriate aero helmet can save you in the neighborhood of 1 sec/km, sometimes more, so in a 40km ride, that's ballpark 40 seconds. For slower riders, a bit more (aero improvements roughly scale evenly across fast and slow riders, but since slow riders are on course longer, their raw absolute time savings are greater).

Even really really high up in the ranks of triathletes, they don't usually know. Sometimes they know for themselves but they won't know for someone else.

The bike leg of an Oly Tri is 4x longer than the run, so if you're 1 sec/km faster on the bike, that's the equivalent of running about 4 sec/km faster, or about 6 secs/mile. Runners know that improving their pace by 6 secs/mile is actually not a trivial amount. (And you're still allowed to do both).