Added mirror extenders to the TDM in an attempt to reduce buffeting. Bought the extenders off ebay, reasonable price and simple to install.
I'll give them a test later in the week.
Extenders smoothed out the airflow a little and reduced the buffeting. I'm happy with the result although more testing will be done.
On my last ride both mirrors came loose and swung backwards. A check on the side of the road showed the threads in the mirror perch appeared slightly damaged. Several attempts to tighten the bolts were unsuccessful and the problem re-appeared after a few kilometers. I used superglue in the threads to hold the mirrors in place and get me home. It appears to me that the leverage provided by the additional length allowed the bolt to move thereby damaging the thread. Whilst the extenders worked to reduce buffeting I am removing them due to the fear of permanent damage to the mirror mounts.
Unfortunately the same ride broke a lot of the screws in my clavicle and I am now in recovery after removal of the original plate and replacement with two larger plates and a lot of screws so I won't be riding again until late May.