Locking that clutch up/disabling it wouldn't be that big a deal for a serious builder. I'd love to build a GMAC, currently have a MAC 12t (pretty much the same motor, but WITH internal clutch) that's been absolutely bullet proof for several years now. The reason I don't already have a GMAC is the required display from Grin. When it comes to the functionality of the GMAC, you need the Grin electronics available only from Grin electronics to make it work. If you locked up the clutch in a GO62, and set it up on the Grin controller, you would have what amounts to a Bafang GMAC....