Had a bit of a close call today. Just filled up the bike and was heading down Berowra Waters Road, through the first roundabout, gradually getting up to speed (going about 30km/h at this point) when I hear another bike coming up behind me pretty quickly. I assume he had just come off the Pacific Highway and was still going about 80. My first instinct was to move over to the left of my lane (I was in the middle) so I look down at the mirror to see where he is. As I look down and see the mirror is empty, he suddenly goes flying past me on the inside of the lane, on my left going at least double my speed. It's lucky I took that extra second before moving over, otherwise that could have been even more dangerous. I'm not sure what else I could have done. I guess watch the mirrors more closely or keep more to the left side of the lane? If you see/hear another bike coming up behind you, is it better to stay where you are and let them figure it out or try and move over?