Thanks speedmd, the d7500 is the same sort of design as those gng or bht type motors but its a fair bit bigger.
The airgap is 90mm and a 60mm long stator and those outer bolt holes you can see in the case are 160mm apart, also the case is pretty long because there is a separate and adjustable hall and magnet ring at the back end a little like i made for the Joby -the halls are under the pink epoxy mounted on a thin fiberglass sheet in that pic.
The separate magnets to trigger the halls is often needed as you approach saturation to avoid stray fields from the energized coils giving false signals. likewise adjustable halls are a good setup because ive never seen the halls accurately placed by a factory when checking them with a cro..
And yea you wouldn't really want to rely on the relatively distant rear case of the Joby to take chain loads from the nose, but its a pretty simple thing to have bearings inside the sprocket and mount that internal shaft to the frame.
The new design of the JM1 has the same case, so will bolt straight in to the race bike but its a different pole count and a new stator, the internet knows nothing of the new motor from what ive seen other than some media reports of the joint venture/VTOL project, so i prolly should keep it that way.
The big (154mm) outrunner is an interesting motor, it produces torque very efficiently and has 0.2mm lams. its not happened yet but i believe this motor (at nearly double the weight though
) is capable of making more power than the JM1.
Ill post up info on a rewound version of it shortly.