>have you tried 1 1/2” spacing in a Dadant vs 1 3/8” vs 1 ¼” spacing?
I have tried all of those spacings, but not all of them in a Dadant deep. I did not like the 1 1/2" as they build very uneven comb and you are more likely to roll the bees because of the protruding honey comb, and it takes more bees to cover the brood.http://www.bushfarms.com/beesfaqs.htm#framespacinghttp://www.bushfarms.com/beesframewidth.htm
> Notice any differences in wintering success?
The 1 1/4" will build up faster in the spring. I don't see any significant difference in survival.
> Dadant seemed to think 1.5” space was important.
He thought it would prevent swarming. I don't believe it does.
>According to page 22 of Dadant System of Beekeeping 1920:
“This (1.5” spacing) gives a larger amount of honey than in narrow combs;
Yes, the honey comb will be thicker, but the brood comb is not, so the surface is very uneven.
>the bees congregate there in greater number and thus winter better.
I don't agree.
> They are more powerful in the spring and the cycle of year is reached with better success.”
That was Dadant's opinion, yes.
>I’ve been experimenting with narrow frames this summer and find they’re much easier for me (the bee keeper) to manipulate
> but I haven’t wintered in them yet.
"Frame.--As before mentioned, each stock hive has ten of these frames, each 13 inches long by 7 1/4 inches high, with a 5/8 inch projection either back or front. The width both of the bar and frame is 7/8 of an inch; this is less by 1/4 of an inch than the bar recommended by the older apiarians. Mr.Woodbury,--whose authority on the modern plans for keeping bees is of great weight,--finds the 7/8 of an inch bar an improvement, because with them the combs are closer together, and require fewer bees to cover the brood. Then too, in the same space that eight old fashioned bars occupied the narrower frames admit of an additional bar, so that, by using these, increased accommodation is afforded for breeding and storing of honey."-- Alfred Neighbour, The Apiary, or, Bees, Bee Hives, and Bee Culture...
>Would there be any benefits to a deeper frame, 12" or greater?
I tried deeps for 26 years. Dadant deeps for three or four years. Mediums for the last 10 years. (there is some overlap on these as I've only been beekeeping for 37 years). Now all mine are mediums. No, I didn't see any benefit. I do see a benefit of Dadant deeps over deeps as they will build a taller brood nest (they tend to stay on one deep and hesitate to expand past it). But with mediums they don't hesitate to expand the brood nest into other boxes. They winter better in eight frames, in my observation, because the box fits the cluster; and they winter better in mediums because of better communication and transportation between the frames because the cluster usually spans more than one box so the cluster can easily expand and contract without having to risk getting stuck when the cluster contracts.