Don't look from the front look from the back
For everyone worried about the width of Aluminium Panniers, no matter who they are from, a lot of people make the mistake of looking at them from the back, if you look from the front, you will almost certainly notice that they are nearly always, narrower than your handlebars by a good couple of inches and in most cases only about the same width as your engine bars. So if you can get them through the gap, your boxes will follow.
Caveman