I currently use a Giro Atmos. I use it because, not necessarily in this order, 1) it fits, 2) the price was right (it was on sale), 3) it's fairly light, and 4) it was reputed to have good ventilation. I'm currently in the market for a new helmet, and was wondering if anyone uses specific helmets for summer and winter riding (or more correctly I suppose, hot weather and cold weather riding).

Obviously, for a "winter" helmet, good ventilation is much less important than for a "summer" helmet. I would be more than willing to substitute "wide range of adjustability" for "good ventilation", since depending on actual conditions I could be wearing anywhere from nothing (or maybe Head Sweats) under my helmet, to a balaclava, to a cycling cap, to an ear warmer band, to multiple items, all of which change the circumference of my head. Also, during the winter, much more of my riding is in the dark, so I wear a helmet-mounted light. The Atmos, as well as a couple of others I noticed, has a "ridge" running down the top of the helmet, which (somewhat) interferes with the fit of the helmet mount for my light. It's still useable, but I have to be a lot more careful to "balance" the light on top of the ridge, then really cinch down on the straps.

Anyway, I was just curious about whether this was a crazy idea or not.

Bern has winter liner kits for their Helmets, they sell the same ones to Skiiers, as Cyclists.

as an Example.. a 2 helmet combination not that odd.

I use a helmet cover and a pair of V-muffs. With the other stuff I wear, the balaclava and/or earband. I stay comfortable down below 0f.

Winters are very mild where I live, but sometime the temperatures do drop close to freezing so I avoid my summer Giro Skyline (gloss white) which has very good ventilation and use my Catlike Urban which has a dark grey mat finish and has fewer vents, plus a little built in light on the rear strap.

Edit: Just noticed that this is my 1,000th post!

I have a summer helmet, (a vintage Bell Tourlite) and a winter helmet, (a OGK knockoff of the Bell Tourlite) The only difference is that the winter helmet has all the vents taped with yellow duct tape.

I don't have a separate helmet, but I do wear a knit hat underneath when it gets below freezing.

I have a ski helmet, and it's great for keeping my head warm while skiing on super cold days, but I would feel ridiculous wearing it while cycling, not too mention that there would be sweat pouring into my eyes.

Yes, a ski helmet for when it's really cold. The thing is too hot for anything over about 15F. It's a giro, with openable vents. I don't wear anything under it until it gets below 0F then maybe a thin balaclava. It handles ski goggles well, which is also what I wear under 15F. I also use it for, get this, skiing.

Some years ago, Bell offered their 'Metropolis' model. It wasn't just a bike helmet, it was a bike helmet system with an available snap on rain cover, a visor, a mirror and a winter insulation kit including ear muffs. Cyclists reacted like they were being offered chicken pox, and retailers closed inventory of these out at deep discounts over the next several years. Don't expect Bell or another helmet manufacturer to offer anything like this again anytime soon.

I've got one with all the optional stuff, purchased about forty cents on the dollar. It's a good helmet and all the accessories work well. Yeah, I generally only wear it in the cold or when it's raining. I'm not sure what I'd replace it with.

Hmm, well there is the Abus Cyclonaut. Expensive and AFAIK not retailed in the USA.

I have a Bern with earflaps that I use when it drops below 30. Above 30 I just use a thin skullcap under a regular helmet.

I also use the Bern with the winter liner.

OK. So this isn't exactly a crazy (or new idea). Up until now I rarely rode in the winter, so it didn't come up that often.

My biggest problem, is that I'm just about at the upper limit for the medium Atmos. Once I layer up on my head (beyond a Head Sweats), it doesn't fit that well (I suppose I could shave my head, but . . . ). Like I said, it wasn't a problem when I primarily rode in the spring, summer and fall. But now that I'm commuting in the "winter" (yes, I know, California winter is a nice spring day in many other parts of the country, but humor me), I occasionally wear some form of head gear to keep my ears from falling off.

Thanks for the feedback. Now, to find a poorly ventilated helmet that fits a little loosely . . .

I have a night and a day helmet. As luck would have it the night helmet usually means winter and the day helmet summer.
The night helmet is all decked out with lighting and the day helmet runs naked.

Yes, I pulled out the old crappy pads (better to fit a skullcap) and ziptied a light to an old Bell Sweep. That's my new winter helmet. It's super Fredalicious but I don't care.

I use a Specialized mountain bike helmet with a Giro Ionos Winter liner, along with an ear warmer and/or cap or balaclava depending on how cold it is. I've looked at the Bern but I can't see how to mount a light on it. I've look at ski helmets as well but they don't make sense for my area. Cold mornings and (usually) warm evenings make a dedicated cold helmet like a ski helmet impractical.

I would suggest a less expensive helmet...less ventilation...and the Giro helmet liner

I use a cheap Bell that I can wear a cap or balaclava with additional ear warmers under. I have reflective tape on it for night riding and also have a reflective rain cover that does a great job of blocking the vents. With the balaclava and ear warmers at 25 deg. F with wind chills of -10 it kept my head and ears nice and toasty.

You can't mount a light to it, but I've seriously considered rocking a Giro Air Attack Shield for the coldest of winter days. But that would be pure excess that I can't actually afford.

I generally wear a hat underneath, even in summer (more of a fashionable sweatband for me), however if Giro is a good fit for you, I've actually been pleasantly surprised with the Savant, and it would have less ventilation than your Atmos. I bought it accidentally because I forgot my helmet for a group ride, and it ended up becoming my daily helmet. Retail is 90 bucks, and can probably be had cheaper. Honestly, it's nice enough that I'm not sure if I'll ever let myself spend the near 300 bucks on nicer helmets.

I haven't tried to mount a light to it, though. There is ventilation directly down the center line, so you would have to be wrapping around two sections to get a centered mount. That might not work well inside the helmet fit-wise.

I switch to Giro Nine.9 ski helmet for winter.

little tip I read here on FB and like to share a lot: clear, cheap, motel style shower cap.

easy to stow, protects from rain, yes, but also wind, and because it also traps air, it provides a thermal barrier. it's easy to whip off if you get hot. they are transparent so your reflectors will still light up when headlights hit them. they don't look nearly as dorky as you might think. in fact you'll look smart
https://drivesafely.allianz.com/stati...2035751579.jpg
https://pedalprecision.com/wp-content...shower-cap.jpg

I can fit a polypro balaclava and lycra skull cap at the same time under my regular helmet, which is good down to the teens. Below that, I drive to work. Lights go on the helmet in darker months. No need for a special winter helmet.

I normally like helmets with a visor (think MTB) to deal with low sun angles and glare. So my winter helmet doesn't have a visor so it'll take a helmet cover to stop ventilation and keep the rain out.

+1 on the Bern helmet with the winter liner. It has to be below 30, though, or it's just too much. There are two retainer loops on the ear flaps. If you pass the chin strap on the outside of the loops, the ear flaps fit looser and you get a little wind passing through and the ventilation is good for, say 25-30 degrees. If you pass the chin strap through the loops, the flaps fit tighter and give you protection in colder temps.

Unfortunately, my Giro 100 Proof gloves are only rated down to 16 degrees, though that's pretty optimistic on Giro's part and doesn't take into account wind chill on a bike moving 20mph...

One of my helmets is destined to have a Santa hat permanently affixed. I guess that would be a "winter helmet" although it's just for December.
The other helmets:
. The Night Helmet, with the helmet-mounted strong headlight and a rear flea blinkie.
. The Daily Helmet, HiVis yellow with black decorative graphics. Matches my HiVis attire.
. The Fashion Helmet, a simple light gray helmet that looks nice with my club jersey and other non-HiVis jerseys.

Lazer Helium. Aero shell and ear muff insert. Just got the helmet in early fall. Have used the shell and insert a few times on 45 degree days. Works well, stay nice and warm.

Now I just need to spring for winter cycling shoes.

Cheaper helmets usually have more polystyrene and less air.
Met brand has a really good adjustable band system rather than pads.