Sorry for hijacking your thread. Back to your original question. The main problem I ran into is the varying angels of the bike tubing. I personally like to fit the front mount first for looks. No drilling, just good fitting. No rubber, no epoxy, just good metal to metal fitting. Doing it this way usually I find the rear is off a few degrees, but no more than that. If you make a wedge to install at the motor base and then slip the curved mount that your kit came with onto the studs, as you tighten, they will conform to the angel of the seat post and leave no gap. You will have to leave the front loose and kinda cinch both down at the same time as the motor settles into the lowest point. I like to mount the motor as low as possible and keep spacers to a minimum. This method has always worked for me although It takes some time to match the diameters of the mounts with the bike tubing.