Quick HO & N gauge question

A friend would like to know what the smallest radius is on N gauge and I don’t have a clue. Knowing that there’s an answer here I’m asking for your help. Currently he has HO but is thinking about N. Here’s his question:

Do you know what radius you can operate N gauge track, how small can you go and still get by with it?

Thanks for your help.

the smallest radius in nscale sectional track is 9 1/2". i have seen a small display layout at a show where the radius looked like 6 or 7" radius. the operator of that layout was running short diesels and steamers with no more than 40’ cars or old time passenger cars. i wouldn’t go tighter than 9 1/2". 15"r in ho is about the same as 9 1/2"r in n.

I don’t have any experience with 9.5" curves–the tightest ones I use are 9.75". All of my diesels, and the two steam engines I have (Bachmann 2-8-0 and Light Mountain 4-8-2) run fine on it. They do OK pulling Con-Cor 80’ (or is it 85’?) cars without derailing, but they do look very silly and awkward over the 9.75" curves.