Minimal logging for bulk inserts?
Paul White has a really detailed post about a way to get minimal logging for INSERT...SELECT statements that target clustered tables with secondary indexes.  Check out the full article here:
Minimal Logging with INSERT…SELECT and Fast Load Context
The main thing you're probably missing is that you need to enable trace flag 610.
Read the whole thing to see make sure you get past all the conditions and edge cases - especially around estimated number of rows to be inserted, existing number of pages in indexes, and the estimated data size of rows being inserted.