Crackpipe Lightmount [preorder]
This light mount fits B&M and SON type rear dynamo lights. The mount is made from silver soldered stainless steel parts and bolts on to your frame using M5 bolts and can be used on any mudguard/fender or rack mount that is M5. It can be used on both drive side and non-drive side.
WARNING: The light mount is relatively long and exposed when mounted in a mudguard stay boss and could potentially damage your frame if hit in a crash or similar force. It is likely that bolt will just snap or bend in a collision but I can not recommend mounting the mount to a carbon frame. On a steel frame on the other hand I have never had any issues personally.