To keep my head warm on cold winter mornings....

I can't it a beanie too well with my helmet and I often don't wear a beanie or wear one and not my helmet.

Well, the helmet debate is another whole *issue*, but for me, I always wear a helmet, and I've managed to successfully fit close fitting hats (toques up here in Canada) under my helmet. I have a Louis Garneau helmet that is quite forgiving and adjusts to all sorts of head gear, and I have a *big* head (ha ha) so I'm quite impressed. It's about -10C right now, so it works pretty well.

I use a wool beanie from Icebreaker, works very well, does not take up a lot of room, and does not take a huge change in my helmet adjustment, YMMV...

How about a helmet cover:
https://www.amazon.com/gp/product/B00...NJHXKN5R4FBAQN

The coldest temperature on record for Mesa is 20 degrees F -- should be able to get by with a thin headband that covers the ears.

(Unless you're bald, I guess. Then a thin balaclava would do the job.)

I've had ditch the helmet to to fit one of these on my head:

https://www.sierratradingpost.com/out...women~p~52327/

But unless the temp is below 0 F, I can get by with just a headband. I wear this one:
https://www.rei.com/product/790913/rei-thermo-earband

Headbands fit under your helmet just fine, even thicker ones. For my money, a thicker headband keeps me warmer than a thin hat.

Target has some good C9 skullcaps that cost about $12, IIRC. In Menswear by the running clothes. One of those fits under the helmet and works nice for those temps. Make sure it can cover the bottoms of your earlobes.

Are you riding in the Mesa, AZ, area? Weather.com shows your daytime highs for the next 10 days in the upper 60s to upper 70s F and lows in the 40s and 50s. I'll assume that you don't ride in the wee hours between midnight and sunrise, so you are probably riding in temps of 55+F. A very light skullcap or even a cycling cap will serve the purpose well with no need to ditch the helmet. Unless your helmet is already at it's maximum adjustment, a click or two on the adjustment wheel should be all that is needed.

Yeah the low temp may not seem like much but we're used to 100+ degree weather so that's pretty cold to me. I'm not bald, and I've been wearing a thin, wicking beanie from Nike. It helps a lot but I feel the rest of my body would get warmer if I warmed my head more.

thanks for all the other tips everyone. Pretty glad I don't have to sacrifice the safety.

In MN I ride with a helmet, beanie underneath, when ice is on the ground... so much of winter. I have warmer hats to ride in when this is not the case, but the difference in comfort is not enough for me to forgo a helmet on icy days, when I may go down due to factors outside of my control.

Try a skiing helmet (or just buy a cheap larger helmet you can more easily put over a baraclava).

Meh. I don't use a helmet in the winter. The risks of winter head trauma are smaller for me, I have a soft beanie and other hats when needed.
Fitting enough head gear under a helmet and covering places that matter is, I find, next to impossible. Also there is the whole forehead issue. When it gets to -25° C I need to really cover my forehead with a special beanie and buffs etc.

Also, my beanie is a hair styling device in the winter and a helmet cramps that up too much.

At temps in the 50s, a beanie should be adequate. If the rest of your body is cold, you might want to invest in a long-sleeve jersey, wind vest, long-fingered gloves and wool socks. Knee and arm warmers are an option too and easy to shed if you get too warm. Don't worry if you are a bit on the cool side when you start out. After your warm up you should aim for keeping the temps just comfortable and minimizing perspiration. While you may be used to riding soaking in sweat in the summer, in cool weather, drier is better. Remember that perspiration does not directly correlate to effort or calories burned. You can sweat profusely reclining in a sauna or burn a huge amount of calories shivering in a cold wind. Layering with 1/2, 3/4 or full zippers in the front give you excellent thermoregulation. Just adjust to the cool but comfortable even at your peak efforts. If I come back from a winter ride with my innermost layer just damp in spots, not soaking, and haven't experienced any hard shivering, I feel I did it right.

A ski Helmet is actually warmer and a positive wind break when temps are below 0 F.

I have all of those things you mentioned. I'm pretty warm when I get to school in the morning except for a few extremities. Wonderful tips too, thanks.

+1 a thin windproof headband is all you need. Or buy a helmet that fits better. Any helmet you buy should be adjustable enough to fit a thin layer under it.

I find it's not the helmet which is the problem. It's the gap between the helmet and ski goggles. What keeps me warm in the really cold is a windstopper beanie and two buffs. The beanie is tucked under the ski goggles.

A ski helmet is expensive. Too expensive even. I might consider an extra helmet if I got one on the cheap but you rarely find them where I live.

But I would still use one just for the actual mountain biking. The regular everyday cycling in the winter for me is not that risky. But of course we don't really get ice since it's constantly below freezing.

This is what I am considering too. I saw a winter bike commuter the other week wearing a Bern snowboarding helmet: it looked warm.

You bet it is. I've got a Bern Watts hardhat with the knit liner and my hair gets wet with sweat unless it's 15 below zero or colder on a 3 mile commute.

I have this under my helmet: https://www.amazon.com/Zanheadgear-WB...ords=balaclava

M.

I also have a Bern Watts helmet with what they call a winter kit.

https://bernunlimited.com/shop/snow/men/watts.html

It keeps me warm down to the 40's F. Below that I add a balaclava underneath.

I used to have a Bell Metro helmet which also had a winter kit, but unfortunately they stopped making it.

I wear a Giro snowboard helmet. It has the ear pads which are fantastic and little screens in the vents which keepsnow out. I'm a fan.

I bought a cheap beanie from Sports Authority on sale for $12 and it fits perfect under my helmet and keeps me warm.
Im in Chicago and I would never get on my bike without a helmet.

Ibex wool cap, Ibex wool hoodie under a regular summer bike helmet. I was warm down to 10*F + windchill this past week here in Boston, and I'm usually a freakin' lizard.

I don't usually say this but Belgian up, duder.

If your jacket has a hood, I'd think that should fit under your helmet. You really don't need anything thicker unless it goes <20F.
Also, if you wear a helmet the rest of the year, winter is the worst time to ditch it since it's slippery and your chances of falling are higher. No, snow won't make it a soft landing for your head.