What Are Spoke And Subheader
Welcome to the forums! I am not a teacher.
I think you refer to this thread by Administrator Red5 as below:
How you can narrow your topic to a single spoke or to a sub-header of a spoke on the map
Please click the URL link to have a vivid image of spokes. 'Spokes' here is a metaphor, which refers to a subject of essay can elicit many topics.
Google ???? http://www.mobwires.com/mob_wire_images/mob_wire_wheel_images/mob_wire_wheel_large/mob_spinning_spoke_lg.jpg ???
For example, if you start a essay titled 'music', which can elcit many spokes--jazz, classic, rock 'n' roll, country music, etc. Obviously, 'music' would be too big as an essay, you have to narrow the topic to a single spoke- country music or any other music you like to talk about, or you will have to cover all kinds of music which might be too difficult to write.
Hope this helps.
PS: Could you please offer more context if you pose your questions next time? I understood what you refer to because I happened to read this article before.