The issue I have is the holes in the frame are threaded, so the bolt only screws in as far as the threads allow.
Are the bolts I got correct or should the holes in the mounts NOT be threaded? To use the bolts I bought from AMOC I would need to drill out the frame hole a little bit, or extend the threading on the bolts.
as I recall, only one side of the rear footrest bracket is threaded. the other is a clearance hole. This is to allow the bolt to be fully tightened up, but allow the footrest to pivot, if the the bolt was threaded further down, it would A. Fret the hole in the footrest & B. Lock the footrest & not allow it to pivot up & down. The half nut is there to lock the bolt in place & the pressure on the footrest arm, to stop it dropping down, is made by tightening the bolt with sufficient pressure to slightly squeeze the mounting bracket
You are correct. I found the bolts didn't want to go through, but I persisted and finally it did and screwed in as far as I could but then run out of thread before it tightened.
I simply added a small amount (2mm) of extra thread which allowed it to screw all the way in and squeeze the pillion footrest.