29mm. It would be thin wall from Madcow or carbon from Wildman. To be entirely honest, I'm mostly interested for simulation purposes, since it seems that no manufacturers of filament wound carbon say how much it weighs. If someone could tell me the weight of a different diameter of carbon tube, I could probably math it out from there.
Composite airframes have relatively standard inner/outer diameters. I know for a fact that a filament wound fiberglass nosecone from Wildman fits properly on fiberglass tubes from Wildman, Madcow (technically Rocketry Warehouse, but now that tube is from Madcow), and Apogee. I guess it might be different for carbon fiber tubes, but as far as I know, carbon fiber tubes are made the exact same way as fiberglass. It would make sense that theyalso fit the standard inner and outer diameters.