shankster said:
Interested to learn more about
"Geared hub motors can be ran in reverse and use regenerative braking, contrary to popular opinion. All you need to do is lock the clutch."
Can you elaborate or is there a thread on how this can be done?
Few have gone into much detail into doing this themselves. The only attempt that I can recall seeing with a degree of illustration was when someone coated their clutch with JBweld. https://endless-sphere.com/forums/viewtopic.php?f=4&t=10458&hilit=45&start=45#p212576
This JB weld attempt eventually failed, https://endless-sphere.com/forums/viewtopic.php?f=4&t=10458&hilit=45&start=45#p282632
So far as I know, all electric bicycle hub motor clutches are simply two rounded plates spinning across (or with) each other with a bit of grease (if you are lucky) in between them. The idea, at least in my opinion, is to weld the two rounded plates together where they meet. A potential technique for this is to remove the gears(and anything else you don't want to get hot, like bearings) from the clutch, degrease the clutch assembly, place the clutch assembly into an oven and heat it up well,(preheat reduces risks for warping), after the part was heated remove it from the oven and then TIG weld the joints. You probably wouldn't need to do a ton of welding, as in you don't need a ton of heat or penetration, and may not even need any filler. I'd toss the clutch back in the oven to cool, turning the oven off after the clutch was placed back in. You could probably skip the pre/post heating thing if the clutch was thick enough and you weren't too worried about it warping (especially if you have spares for trial and error).
http://imgur.com/a/s8SWu These pictures are of the clutch assembly from one of the Q100h geared hub motors I have and should illustrate some of what I mentioned. The Q100h is probably a good candidate for your criteria, it weighs 2.2kg, but this modification is pretty intense and there is still more you'd need to do. The motor would need to be ran with oil inside of it as well. The oil would act as a thermal transfer fluid, getting the heat from the inside of the motor to the shell much more effectively. You could probably run a Q100h at around 500w continuously with around 30-40ml of oil without much need for worry, though some folks run this motor stock at higher power levels, I am sure the oil will lengthen the life and improve reliability, especially protecting the hub from corrosion.
I didn't mention this, but a vented and sprayed direct drive hub motor which was once rated for 350w would now likely be rated for around 1050w, certainly far more than 500w. Personally, if I was going to recommend one or the other to you, I'd suggest venting and spraying (VS) a direct drive hub motor. VS will likely be a substantially easier modification and it seems unlikely that zero oil will leak from an oil cooled geared hub motor.
