rsbob 

Used to bike commute in my 30s and 40s when the temps were in the high 20s and low 30s and it was not comfortable even with tons of cycling specific cold weather gear. I knew it was cold when the pavement reflected ice crystals from my headlight. I would sweat through one pair of ski gloves and switch half way with a fresh set for the remaining eight miles.

One ice crystal morning in the dark I was being super careful at 15 MPH because of the slick path. Another commuter passed me doing about 2-3 faster and when he got about 50’ ahead of me, going perfectly straight, WHAM, his bike came out from under him and down he went. I checked that he was ok and then slowed to 13.

Now that I’m in my mid 60s, the mid 40s are about as cold as I will go for training rides. What about you?

10 Wheels

Commuted on a motorcycle 28*F

Seattle Forrest

In bike specific stuff? 50F, maybe a little lower. In hiking clothes, I'm not sure, teens? I've night skied at -10F.

diphthong

cycling...40 degrees f with the promise it'll warm up to at least 65 degrees f.

dabac

I’ll ride in any temperature I’d ski or skate in.

SurferCyclist

If it's icy don't ride, simple. Way too dangerous and not worth risk.

rivers

It depends if it's been wet or dry. Wet, it will need to be a couple of degrees above freezing (around 2C). Dry, I've commuted down to -8C. I use my snowboarding or diving baselayers, which are wool, bamboo, or a fleecy synthetic material, bib tights and a winter jersey, plus a fleece beanie under my helmet, maybe a balaclava or buff if it's really cold. Merino wool gloves with some cycling specific gloves over them, and a set of bar mitts. The bar mitts have been a game changer because they keep the wind off. My commute is around an hour, and it means I can feel my fingers through the whole ride. I will do the same for a club run, but will make my decision on whether or not I ride on a variety of factors. Usually, if it's been that cold and miserable, my friends and I will wait until the sun comes up and go out a bit later in the day, even if below 0. I don't have the luxury for commuting, so from late November to early February, I'm commuting in the dark, usually both ways.

Ghazmh

18 degrees Fahrenheit is my cut off.

datlas 

This. You can dress for the cold. It’s unsafe road conditions that make me skip a ride.

jpescatore

I motorcycle commuted in my 20s, had a snowmobile suit and a full helmet/face shield and in dry conditions, I was pretty comfy on the way in when it was in the low 20s. Any chance of ice (or those mornings where lots of people are driving around with tiny viewing ports scraped into their windshields instead of waiting for the defroster to do its thing...) and I wasn't on the motorcycle.

Bike commuting in my 30s and early 40s, below 30 it just wasn't fun and had the same rule about any ice possibilities.

Now, recreational riding below 40f is just not fun - it is always in the 50s or 60s in the basement where I can wimp out and ride on trainer/Zwift!

WhyFi

~20° is usually my recreational riding cut-off point, but if I'm getting stir-crazy, I'll stretch that a little.

Sounds like you may have been over-dressed for the level of exertion. For commuting in the winter, I would aim for warm but not sweaty, adjusting effort and/or apparel as necessary.

Or get some studded tires.

deacon mark

Don't ride in ice. I took spill on it turning on some black ice cost me 3 stainless steel screws in my left hip. Thank goodness it was not displaced and went back at running in 16 weeks but no ice riding............the deacon fears ice.

seypat

If you have to bring in the brass monkeys from your porch...............

CAT7RDR

Even on a MTB with urban treads, I felt dicey riding on icy sections on Glendora Ridge Rd. Pretty to be up in the snow at 36F but definitely not a good place to be injured with no cell reception and no one else on the road. So 40F and sunny with no ice for me fits better.

Reflector Guy

It's been a long time, but I recall riding at temperatures well below freezing back when I was around 19-20-21 or so. You know, back when we were indestructible. Fifteen degrees maybe? I had places I needed to be so I just piled on the coats.

No way I would do that now. Even in normal temperatures, the cool breeze I get while riding bothers my eyes, and when the temperatures drop even into the 50s I have to wear goggles.

Seattle Forrest

On very cold days (20s F) I wear a thin base layer, a light soft shell for the wind, and a down vest as an outermost layer. Plus long pants. The zipper gives you a lot of control over how much insulation you get, and if the sun comes out the vest packs down to nothing.

It looks unusual for road cycling but it's extremely conformable and less goofy than my superhero outfit.

(Winter days here are either 40-45 and raining, or < 32 and dry and clear, icey roads happen but not that often.)

impolexg

Decades ago I lived in Hokkaido and commuted by bicycle (mountain bike) all through the winter and usually I had no issues at all. I had some steel studded mtb tires that worked ok but the best were some huge super soft knobbies that seemed to have the best grip, especially in ice. There was one time where I had to cross a larger city street from a side road, there was powder snow blowing across this water ice. I was alert because I noticed some local pedestrians having trouble standing so decided to walk the bike. About half way across the street my grippy sorel boots went out from under me and I went down, and I literally I could not stand even with bicycle as a crutch. I had to crawl the rest of the way across the street dragging my bicycle behind me. Never since have I experienced such a slippery surface.

I had ice climbing gloves, sorel felt boots and was generally fine. The trick is to work hard enough to be warm without sweating from the torso. A few times the temp dropped south of 0f and I stopped being able to manage my temperature, even with an enormous baffled down parka the wind would just suck the heat away - I'd come in after 45 minute ride with a headache and my core chilled in a bad way. I didn't have any warmer clothes so I just stopped going out when it was that cold.

You really don't want to find yourself sweating, be attentive and stop and manage your layers. If you sweat you will freeze when you stop.

Seattle Forrest

This. If you're not a little cold when you walk out the door, you're going to be overheating a few miles in. It's important to sweat as little as possible in winter conditions. (And we all have a unique thermostat so it takes some experimenting to find what works.)

Iride01 

I'd let your desire to ride and ability to dress properly for the conditions and things like wind, rain, snow, ice and etc. from one day to the next determine that.

caloso

Freezing, which is about as cold as it gets here.

HarborBandS

I’ll ride in any temperature, but I avoid riding if there is snow, ice, or road salt. And frankly, I like the road salt to be washed away by a rain shower or two in the Spring, if I’m riding my nicer bikes. That can be well in to the Spring in Chicagoland.

dabac

Our bodies don’t all work the same way WRT temperature management. Mine runs on a simplified program: pulse up = sweat on
And that’s it really.
If I dress down to the level where I don’t sweat, I get hypothermic.
I usually don’t notice while I’m moving though, it hits me when I stop. It’s been so bad I’ve had to be helped inside, couldn’t manage the key.
My modified approach is to dress so that I don’t soak EVERYTHING, and to swap out the sacrificial base layer at every longer stop.
I spent years chasing the holy grail of just right clothing, got into a couple of nasty situations due to being underdressed. Now, I pick a different approach of moisture management and is generally both more comfortable and safer during winter exercise.

zatopek

Ditto

bampilot06

I’ve gone out in low 30s
I don’t have all the specific gear yet, I use what I have, it works but after about 90 mins I can start to feel the cold, and touching two hours I will have to stop. Just means when it’s cold I plan on shorter rides.

DangerousDanR

Living where I do the coldest I have ever ridden is -35F. I was OK, but I have gear to keep me warm.

I agree with the concerns about ice on the pavement, but I have found that studded tires make a huge difference. If I lived where it is not icy for several months each year I would probably not ride until the ice was gone.

But, if you are in the Great White North, get studded tires and ride just a little slower. With the appropriate gear it can be a lot of fun.