From this picture, it appears to share the ~200mm stator diameter with the 9C. I was hoping it was Magic Pie diameter. Still the biggest baddest bicycle frocky out there right now though, so I'm not complaining.
It's twice the width of a 9C.
They are both 51teeth and 46poles. (or 23 pole pairs if you're a fancy pants)
The tooth/slot profile looks
identical to a 9C.
The 18x4 winding works out to be 72 pieces of copper in the slot though, which is not possible to fit (getting more than an 8x8 at 64pieces is extremely difficult), which tells us it's either using a smaller wire gauge size in the 9C stator lam, or it's a larger/deeper slot. I think they normally wind with 24 awg wire pretty universally for most all hubmotors, so I would like to think it's a deeper slot, which would make it even better than a pair of 9C motors in a single motor, with 50% less end-turn copper loss (which is a pretty huge advantage alone).
A normal 9C's distance measured from the top of the tooth to the steel hub they are pressed upon is 17.25mm.
A normal 9C's slot depth from top of the tooth(edge above the slot) to bottom of the slot is 15.1mm.
A normal 9C's slot width is ~5.2mm (hard to measure well on my wound motor example I'm looking at).
The OD of the enameled wire on a normal 9C is 0.56-0.58mm (the varnish thickness varies slightly), the copper is 0.51mm 24awg.
If we could get some slot dimensions of this motor to compare to the 9C's slot dimensions, and the diameter of the wire used, we should be able to determine pretty well if this motor is indeed a double-wide 9C. Which would be pretty great, way less copper loss from end-turns than running a pair of 9C motors, and the 9C has an excellent magnetic design.
I would hoping it would turn out to be a triple wide magic pie... but this is still fantastic.