Kurt wrote:I am just thinking that perhaps the speed that the gears will be turning/meshing together at 72v will give you to much friction and the gears will fail again. Are you sure its the torque that is making them fail ?
I'm not sure, no. I think both failures occurred on hills however. At 72v if I go WOT from a stop or up a steep hill I think I'll strip the gears even on 10A. I would have to be careful, but it may be possible to reliably operate it as such if I'm only winding it up all the way on the flat, downhill, or gentle inclines. With a bit more km's ridden with the hub I *think* I'm developing an ear for the sound of a straining gear. I'd much rather replicate Nogwin's setup with 66V ~30A but my batteries just don't have that flexibility.
gear speed, torque, heat, lack/loss of lubrication, mechanical shock, meshing issues (maybe gears care compressing under weight of the bike creating a gap between the nylon gear and ring gear at the top of the hub?).
All sorts of possibilities, and no easy way of knowing for sure.