My install of the BBSHD did not go as smoothly as Dogboy1200's install. I have previously installed a BBS02 (68mm) and a Cal-Ebikes BBS02 100mm conversion. Both installs went smoothly. The problem encountered with the BBSHD 100 mm install, is that fat bikes must have their chainstays get wide very quickly, in order to accommodate the 4.5 inch plus wide tires. With MOST 100mm bikes, the BBSHD's new thicker housing will not install flush against the bottom bracket with or without the chainring installed. This requires adding spacer rings (which are not supplied by Bafang) on the drive side, which makes the chainline much worse than the old BBS02. Also, adding spacers reduces the available threads to mount the motor at the fixing plate (left) side. In addition, you probably will have to buy a left crank arm with more offset to clear the left chainstay because you installed spacers on the drive side. You wonder if Bafang even looked at a fat bike when they designed the BBSHD 100mm or just ripped off California Ebike's design and made it more robust. But the jury is still out on how robust the HD is. According to Karl at Electric-Fatbike.com, Bafang is still using the same BBS02 plastic gear in the HD. This plastic gear has failed for me and many others in the BBS02. The higher power of the HD can only cause the plastic gear to fail more often.