I'm mainly interested in carburated air cooled MC engines, but any and all would be interesting as well. I'm wondering what is the coldest ambient temperature you have started/ridden your motorcycles at. Without electric gloves, vests, grips, etc.
In Germany i use to ride all winter up to about 19999-2000, i liked it.
The bikes i had over the years for around town and winter were smaller and lighter, the FJ600 was a good little all rounder as is the CB Seven Fifty, both use carburetors and are air cooled.
These are little bikes with skinny tires that can be thrown around easily and very easy to ride but with about 75 HP they had enough power to get going if they had to.
Temps down to about 20f and up to 2" of slush were okay. 10w30 oil, they they start right up, just let it warm up a little bit and no problems with the machine only from from the complaining neighbors.
No electric anything but good Held Arctic thermal Goretex gloves, Frey Daytona Goretex boots, Rukka outlast Goretex jacket and pants with Rukka thermal underwear did the job just fine, never cold.
Shoei full face with fog shield on the inside of the visor and Rukka thermal neck and chest piece completed my winter outfit.
You will not ride a HD with leather and a salad bowl helmet and goggles in the winter. LOL
Back in the '80s when I lived in Milwaukee I had a Yamaha SR-500F that I would ride into early December if the roads were clear. The SR had a single cylinder 500cc kickstart only engine. I don't recall the absolute lowest temp, but it was certainly below freezing. I'd only put it away for the winter after the first lingering snowfall kept the streets covered with ice and packed snow.
I ride mine year round with such an outfit. Only I add a couple things to it. Those wrap-around the back of the neck earmuffs, and chaps of course. Sweatshirt underneath and gloves. Coldest I've ridden in was 25* through Colorado one year. I honestly stayed fairly warm.
Years ago I rode a new Yamaha XS400 to work until mining season ended in November. Coldest temp I remember was 21 degrees at home after 20 mile ride. Had to park on a hill and bump start it as starter would not spin engine fast enough to start. I don't recall oil viscosity, as it was factory fill.
Oh my gosh I am way past the point of suffering for my art. Heated grips, vest and socks are always with me when I am sport touring. Why be cold?. My body is not as self heating as it use to be. Once you travel heated and toasty when others in your group claim to 'be fine', ha, ha, right. Hey, tougher than I am....when the fog turns to ice on your shoulders at 70mph, you know it's cold where you are....