I used to ride with panniers all the time on my Langster with 405mm CSs. Looks like the Steamroller's CSs are a little shorter than that (398mm). You would probably need a long rack and panniers that can be adjusted to sit really far back on that rack. With much weight that far back, the front end can get pretty light. There were times that I literally had to hold down the bars to keep the bike's front end from wanting to flip up when I got off the bike.